`
mmdev
  • 浏览: 12933149 次
  • 性别: Icon_minigender_1
  • 来自: 大连
文章分类
社区版块
存档分类
最新评论

IOS 数据存储

 
阅读更多
ios数据存储包括以下几种存储机制：

属性列表

对象归档

SQLite3

CoreData

AppSettings

普通文件存储

1、属性列表

[cpp]view plaincopy
  1. //
  2. //Persistence1ViewController.h
  3. //Persistence1
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<UIKit/UIKit.h>
  10. #definekFilename@"data.plist"
  12. @interfacePersistence1ViewController:UIViewController{
  13. UITextField*filed1;
  14. UITextField*field2;
  15. UITextField*field3;
  16. UITextField*field4;
  17. }
  18. @property(nonatomic,retain)IBOutletUITextField*field1;
  19. @property(nonatomic,retain)IBOutletUITextField*field2;
  20. @property(nonatomic,retain)IBOutletUITextField*field3;
  21. @property(nonatomic,retain)IBOutletUITextField*field4;
  23. -(NSString*)dataFilePath;
  24. -(void)applicationWillResignActive:(NSNotification*)notification;
  26. @end

[cpp]view plaincopy
  1. //
  2. //Persistence1ViewController.m
  3. //Persistence1
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"Persistence1ViewController.h"
  11. @implementationPersistence1ViewController
  12. @synthesizefield1;
  13. @synthesizefield2;
  14. @synthesizefield3;
  15. @synthesizefield4;
  17. //数据文件的完整路径
  18. -(NSString*)dataFilePath{
  19. //检索Documents目录路径。第二个参数表示将搜索限制在我们的应用程序沙盒中
  20. NSArray*paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
  21. //每个应用程序只有一个Documents目录
  22. NSString*documentsDirectory=[pathsobjectAtIndex:0];
  23. //创建文件名
  24. return[documentsDirectorystringByAppendingPathComponent:kFilename];
  25. }
  27. //应用程序退出时，将数据保存到属性列表文件
  28. -(void)applicationWillResignActive:(NSNotification*)notification{
  29. NSMutableArray*array=[[NSMutableArrayalloc]init];
  30. [arrayaddObject:field1.text];
  31. [arrayaddObject:field2.text];
  32. [arrayaddObject:field3.text];
  33. [arrayaddObject:field4.text];
  34. [arraywriteToFile:[selfdataFilePath]atomically:YES];
  35. [arrayrelease];
  36. }
  38. /*
  39. //Thedesignatedinitializer.Overridetoperformsetupthatisrequiredbeforetheviewisloaded.
  40. -(id)initWithNibName:(NSString*)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil{
  41. self=[superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];
  42. if(self){
  43. //Custominitialization
  44. }
  45. returnself;
  46. }
  47. */
  49. /*
  50. //ImplementloadViewtocreateaviewhierarchyprogrammatically,withoutusinganib.
  51. -(void)loadView{
  52. }
  53. */
  57. //ImplementviewDidLoadtodoadditionalsetupafterloadingtheview,typicallyfromanib.
  58. -(void)viewDidLoad{
  59. [superviewDidLoad];
  60. NSString*filePath=[selfdataFilePath];
  61. //检查数据文件是否存在
  62. if([[NSFileManagerdefaultManager]fileExistsAtPath:filePath]){
  63. NSArray*array=[[NSArrayalloc]initWithContentsOfFile:filePath];
  64. field1.text=[arrayobjectAtIndex:0];
  65. field2.text=[arrayobjectAtIndex:1];
  66. field3.text=[arrayobjectAtIndex:2];
  67. field4.text=[arrayobjectAtIndex:3];
  68. [arrayrelease];
  69. }
  70. UIApplication*app=[UIApplicationsharedApplication];
  71. [[NSNotificationCenterdefaultCenter]addObserver:self
  72. selector:@selector(applicationWillResignActive:)
  73. name:UIApplicationWillResignActiveNotification
  74. object:app];
  75. [superviewDidLoad];
  76. }
  79. /*
  80. //Overridetoalloworientationsotherthanthedefaultportraitorientation.
  81. -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
  82. //ReturnYESforsupportedorientations
  83. return(interfaceOrientation==UIInterfaceOrientationPortrait);
  84. }
  85. */
  87. -(void)didReceiveMemoryWarning{
  88. //Releasestheviewifitdoesn'thaveasuperview.
  89. [superdidReceiveMemoryWarning];
  91. //Releaseanycacheddata,images,etcthataren'tinuse.
  92. }
  94. -(void)viewDidUnload{
  95. self.field1=nil;
  96. self.field2=nil;
  97. self.field3=nil;
  98. self.field4=nil;
  99. [superviewDidUnload];
  100. }
  103. -(void)dealloc{
  104. [field1release];
  105. [field2release];
  106. [field3release];
  107. [field4release];
  108. [superdealloc];
  109. }
  111. @end

===================================================================================

===================================================================================

2、对象归档

[cpp]view plaincopy
  1. //
  2. //Fourlines.h
  3. //Persistence2
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<Foundation/Foundation.h>
  11. @interfaceFourlines:NSObject<NSCoding,NSCopying>{
  12. NSString*field1;
  13. NSString*field2;
  14. NSString*field3;
  15. NSString*field4;
  16. }
  17. @property(nonatomic,retain)NSString*field1;
  18. @property(nonatomic,retain)NSString*field2;
  19. @property(nonatomic,retain)NSString*field3;
  20. @property(nonatomic,retain)NSString*field4;
  23. @end

[cpp]view plaincopy
  1. //
  2. //Fourlines.m
  3. //Persistence2
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"Fourlines.h"
  11. #definekField1Key@"Field1"
  12. #definekField2Key@"Field2"
  13. #definekField3Key@"Field3"
  14. #definekField4Key@"Field4"
  16. @implementationFourlines
  17. @synthesizefield1;
  18. @synthesizefield2;
  19. @synthesizefield3;
  20. @synthesizefield4;
  22. #pragmamarkNSCoding
  23. -(void)encodeWithCoder:(NSCoder*)aCoder{
  24. [aCoderencodeObject:field1forKey:kField1Key];
  25. [aCoderencodeObject:field2forKey:kField2Key];
  26. [aCoderencodeObject:field3forKey:kField3Key];
  27. [aCoderencodeObject:field4forKey:kField4Key];
  28. }
  30. -(id)initWithCoder:(NSCoder*)aDecoder{
  31. if(self=[superinit]){
  32. field1=[[aDecoderdecodeObjectForKey:kField1Key]retain];
  33. field2=[[aDecoderdecodeObjectForKey:kField2Key]retain];
  34. field3=[[aDecoderdecodeObjectForKey:kField3Key]retain];
  35. field4=[[aDecoderdecodeObjectForKey:kField4Key]retain];
  36. }
  37. returnself;
  38. }
  40. #pragmamark-
  41. #pragmamarkNSCopying
  42. -(id)copyWithZone:(NSZone*)zone{
  43. Fourlines*copy=[[[selfclass]allocWithZone:zone]init];
  44. copy.field1=[[self.field1copyWithZone:zone]autorelease];
  45. copy.field2=[[self.field2copyWithZone:zone]autorelease];
  46. copy.field3=[[self.field3copyWithZone:zone]autorelease];
  47. copy.field4=[[self.field4copyWithZone:zone]autorelease];
  48. returncopy;
  49. }
  50. @end

[cpp]view plaincopy
  1. //
  2. //Persistence2ViewController.h
  3. //Persistence2
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<UIKit/UIKit.h>
  10. #definekFilename@"archive"
  11. #definekDataKey@"Data"
  13. @interfacePersistence2ViewController:UIViewController{
  14. UITextField*filed1;
  15. UITextField*field2;
  16. UITextField*field3;
  17. UITextField*field4;
  18. }
  19. @property(nonatomic,retain)IBOutletUITextField*field1;
  20. @property(nonatomic,retain)IBOutletUITextField*field2;
  21. @property(nonatomic,retain)IBOutletUITextField*field3;
  22. @property(nonatomic,retain)IBOutletUITextField*field4;
  24. -(NSString*)dataFilePath;
  25. -(void)applicationWillResignActive:(NSNotification*)notification;
  27. @end

[cpp]view plaincopy
  1. //
  2. //Persistence2ViewController.m
  3. //Persistence2
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"Persistence2ViewController.h"
  10. #import"Fourlines.h"
  12. @implementationPersistence2ViewController
  13. @synthesizefield1;
  14. @synthesizefield2;
  15. @synthesizefield3;
  16. @synthesizefield4;
  18. //数据文件的完整路径
  19. -(NSString*)dataFilePath{
  20. //检索Documents目录路径。第二个参数表示将搜索限制在我们的应用程序沙盒中
  21. NSArray*paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
  22. //每个应用程序只有一个Documents目录
  23. NSString*documentsDirectory=[pathsobjectAtIndex:0];
  24. //创建文件名
  25. return[documentsDirectorystringByAppendingPathComponent:kFilename];
  26. }
  28. //应用程序退出时，将数据保存到属性列表文件
  29. -(void)applicationWillResignActive:(NSNotification*)notification{
  30. Fourlines*fourlines=[[Fourlinesalloc]init];
  31. fourlines.field1=field1.text;
  32. fourlines.field2=field2.text;
  33. fourlines.field3=field3.text;
  34. fourlines.field4=field4.text;
  36. NSMutableData*data=[[NSMutableDataalloc]init];//用于存储编码的数据
  37. NSKeyedArchiver*archiver=[[NSKeyedArchiveralloc]initForWritingWithMutableData:data];
  39. [archiverencodeObject:fourlinesforKey:kDataKey];
  40. [archiverfinishEncoding];
  41. [datawriteToFile:[selfdataFilePath]atomically:YES];
  43. [fourlinesrelease];
  44. [archiverrelease];
  45. [datarelease];
  46. }
  48. /*
  49. //Thedesignatedinitializer.Overridetoperformsetupthatisrequiredbeforetheviewisloaded.
  50. -(id)initWithNibName:(NSString*)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil{
  51. self=[superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];
  52. if(self){
  53. //Custominitialization
  54. }
  55. returnself;
  56. }
  57. */
  59. /*
  60. //ImplementloadViewtocreateaviewhierarchyprogrammatically,withoutusinganib.
  61. -(void)loadView{
  62. }
  63. */
  67. //ImplementviewDidLoadtodoadditionalsetupafterloadingtheview,typicallyfromanib.
  68. -(void)viewDidLoad{
  69. [superviewDidLoad];
  70. NSString*filePath=[selfdataFilePath];
  71. //检查数据文件是否存在
  72. if([[NSFileManagerdefaultManager]fileExistsAtPath:filePath]){
  74. //从文件获取用于解码的数据
  75. NSData*data=[[NSMutableDataalloc]initWithContentsOfFile:[selfdataFilePath]];
  76. NSKeyedUnarchiver*unarchiver=[[NSKeyedUnarchiveralloc]initForReadingWithData:data];
  78. Fourlines*fourlines=[unarchiverdecodeObjectForKey:kDataKey];
  79. [unarchiverfinishDecoding];
  81. field1.text=fourlines.field1;
  82. field2.text=fourlines.field2;
  83. field3.text=fourlines.field3;
  84. field4.text=fourlines.field4;
  86. [unarchiverrelease];
  87. [datarelease];
  88. }
  89. UIApplication*app=[UIApplicationsharedApplication];
  90. [[NSNotificationCenterdefaultCenter]addObserver:self
  91. selector:@selector(applicationWillResignActive:)
  92. name:UIApplicationWillResignActiveNotification
  93. object:app];
  94. [superviewDidLoad];
  95. }
  98. /*
  99. //Overridetoalloworientationsotherthanthedefaultportraitorientation.
  100. -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
  101. //ReturnYESforsupportedorientations
  102. return(interfaceOrientation==UIInterfaceOrientationPortrait);
  103. }
  104. */
  106. -(void)didReceiveMemoryWarning{
  107. //Releasestheviewifitdoesn'thaveasuperview.
  108. [superdidReceiveMemoryWarning];
  110. //Releaseanycacheddata,images,etcthataren'tinuse.
  111. }
  113. -(void)viewDidUnload{
  114. self.field1=nil;
  115. self.field2=nil;
  116. self.field3=nil;
  117. self.field4=nil;
  118. [superviewDidUnload];
  119. }
  122. -(void)dealloc{
  123. [field1release];
  124. [field2release];
  125. [field3release];
  126. [field4release];
  127. [superdealloc];
  128. }
  129. @end


===================================================================================

===================================================================================


3、SQLite

[cpp]view plaincopy
  1. //
  2. //Persistence3ViewController.h
  3. //Persistence3
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<UIKit/UIKit.h>
  10. #definekFilename@"data.sqlite3"
  12. @interfacePersistence3ViewController:UIViewController{
  13. UITextField*filed1;
  14. UITextField*field2;
  15. UITextField*field3;
  16. UITextField*field4;
  17. }
  18. @property(nonatomic,retain)IBOutletUITextField*field1;
  19. @property(nonatomic,retain)IBOutletUITextField*field2;
  20. @property(nonatomic,retain)IBOutletUITextField*field3;
  21. @property(nonatomic,retain)IBOutletUITextField*field4;
  23. -(NSString*)dataFilePath;
  24. -(void)applicationWillResignActive:(NSNotification*)notification;
  25. @end

[cpp]view plaincopy
  1. //
  2. //Persistence3ViewController.m
  3. //Persistence3
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"Persistence3ViewController.h"
  10. #import<sqlite3.h>
  12. @implementationPersistence3ViewController
  13. @synthesizefield1;
  14. @synthesizefield2;
  15. @synthesizefield3;
  16. @synthesizefield4;
  18. //数据文件的完整路径
  19. -(NSString*)dataFilePath{
  20. //检索Documents目录路径。第二个参数表示将搜索限制在我们的应用程序沙盒中
  21. NSArray*paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
  22. //每个应用程序只有一个Documents目录
  23. NSString*documentsDirectory=[pathsobjectAtIndex:0];
  24. //创建文件名
  25. return[documentsDirectorystringByAppendingPathComponent:kFilename];
  26. }
  28. //应用程序退出时，将数据保存到属性列表文件
  29. -(void)applicationWillResignActive:(NSNotification*)notification{
  30. sqlite3*database;
  31. if(sqlite3_open([[selfdataFilePath]UTF8String],&database)!=SQLITE_OK){
  32. sqlite3_close(database);
  33. NSAssert(0,@"Failedtoopendatabase");
  34. }
  36. for(inti=1;i<=4;i++){
  37. NSString*fieldname=[[NSStringalloc]initWithFormat:@"field%d",i];
  38. UITextField*field=[selfvalueForKey:fieldname];
  39. [fieldnamerelease];
  41. char*update="INSERTORREPLACEINTOFIELDS(ROW,FIELD_DATA)VALUES(?,?);";
  42. sqlite3_stmt*stmt;
  43. //将SQL语句编译为sqlite内部一个结构体(sqlite3_stmt),类似javaJDBC的PreparedStatement预编译
  44. if(sqlite3_prepare_v2(database,update,-1,&stmt,nil)==SQLITE_OK){
  45. //在bind参数的时候,参数列表的index从1开始,而取出数据的时候,列的index是从0开始
  46. sqlite3_bind_int(stmt,1,i);
  47. sqlite3_bind_text(stmt,2,[field.textUTF8String],-1,NULL);
  48. }else{
  49. NSAssert(0,@"Error:Failedtopreparestatemen");
  50. }
  51. //执行SQL文，获取结果
  52. intresult=sqlite3_step(stmt);
  53. if(result!=SQLITE_DONE){
  54. NSAssert1(0,@"Errorupdatingtable:%d",result);
  55. }
  56. //释放stmt占用的内存(sqlite3_prepare_v2()分配的）
  57. sqlite3_finalize(stmt);
  58. }
  59. sqlite3_close(database);
  60. }
  62. /*
  63. //Thedesignatedinitializer.Overridetoperformsetupthatisrequiredbeforetheviewisloaded.
  64. -(id)initWithNibName:(NSString*)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil{
  65. self=[superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];
  66. if(self){
  67. //Custominitialization
  68. }
  69. returnself;
  70. }
  71. */
  73. /*
  74. //ImplementloadViewtocreateaviewhierarchyprogrammatically,withoutusinganib.
  75. -(void)loadView{
  76. }
  77. */
  81. //ImplementviewDidLoadtodoadditionalsetupafterloadingtheview,typicallyfromanib.
  82. -(void)viewDidLoad{
  83. [superviewDidLoad];
  84. NSString*filePath=[selfdataFilePath];
  85. //检查数据文件是否存在
  86. if([[NSFileManagerdefaultManager]fileExistsAtPath:filePath]){
  87. //打开数据库
  88. sqlite3*database;
  89. if(sqlite3_open([filePathUTF8String],&database)!=SQLITE_OK){
  90. sqlite3_close(database);
  91. NSAssert(0,@"Failedtoopendatabase");
  92. }
  94. //创建表
  95. char*errorMsg;
  96. NSString*createSQL=
  97. @"CREATETABLEIFNOTEXISTSFIELDS(ROWINTEGERPRIMARYKEY,FIELD_DATATEXT);";
  98. if(sqlite3_exec(database,[createSQLUTF8String],NULL,NULL,&errorMsg)!=SQLITE_OK){
  99. sqlite3_close(database);
  100. NSAssert(0,@"Errorcreatingtable:%s",errorMsg);
  101. }
  103. //查询
  104. NSString*query=@"SELECTROW,FIELD_DATAFROMFIELDSORDERBYROW";
  105. sqlite3_stmt*statement;
  106. //设置nByte可以加速操作
  107. if(sqlite3_prepare_v2(database,[queryUTF8String],-1,&statement,nil)==SQLITE_OK){
  108. while(sqlite3_step(statement)==SQLITE_ROW){//返回每一行
  109. introw=sqlite3_column_int(statement,0);
  110. char*rowData=(char*)sqlite3_column_text(statement,1);
  112. NSString*fieldName=[[NSStringalloc]initWithFormat:@"field%d",row];
  113. NSString*fieldValue=[[NSStringalloc]initWithUTF8String:rowData];
  115. UITextField*field=[selfvalueForKey:fieldName];
  116. field.text=fieldValue;
  118. [fieldNamerelease];
  119. [fieldValuerelease];
  120. }
  121. //释放statement占用的内存(sqlite3_prepare()分配的）
  122. sqlite3_finalize(statement);
  123. }
  124. sqlite3_close(database);
  125. }
  128. UIApplication*app=[UIApplicationsharedApplication];
  129. [[NSNotificationCenterdefaultCenter]addObserver:self
  130. selector:@selector(applicationWillResignActive:)
  131. name:UIApplicationWillResignActiveNotification
  132. object:app];
  133. [superviewDidLoad];
  134. }
  137. /*
  138. //Overridetoalloworientationsotherthanthedefaultportraitorientation.
  139. -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
  140. //ReturnYESforsupportedorientations
  141. return(interfaceOrientation==UIInterfaceOrientationPortrait);
  142. }
  143. */
  145. -(void)didReceiveMemoryWarning{
  146. //Releasestheviewifitdoesn'thaveasuperview.
  147. [superdidReceiveMemoryWarning];
  149. //Releaseanycacheddata,images,etcthataren'tinuse.
  150. }
  152. -(void)viewDidUnload{
  153. self.field1=nil;
  154. self.field2=nil;
  155. self.field3=nil;
  156. self.field4=nil;
  157. [superviewDidUnload];
  158. }
  161. -(void)dealloc{
  162. [field1release];
  163. [field2release];
  164. [field3release];
  165. [field4release];
  166. [superdealloc];
  167. }
  169. @end

===================================================================================

===================================================================================

4、Core Data

[cpp]view plaincopy
  1. //
  2. //PersistenceViewController.h
  3. //Persistence4
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<UIKit/UIKit.h>
  12. @interfacePersistenceViewController:UIViewController{
  13. UITextField*filed1;
  14. UITextField*field2;
  15. UITextField*field3;
  16. UITextField*field4;
  17. }
  18. @property(nonatomic,retain)IBOutletUITextField*field1;
  19. @property(nonatomic,retain)IBOutletUITextField*field2;
  20. @property(nonatomic,retain)IBOutletUITextField*field3;
  21. @property(nonatomic,retain)IBOutletUITextField*field4;
  23. @end

[cpp]view plaincopy
  1. //
  2. //PersistenceViewController.m
  3. //Persistence4
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"PersistenceViewController.h"
  10. #import"Persistence4AppDelegate.h"
  12. @implementationPersistenceViewController
  13. @synthesizefield1;
  14. @synthesizefield2;
  15. @synthesizefield3;
  16. @synthesizefield4;
  19. -(void)applicationWillResignActive:(NSNotification*)notification{
  20. Persistence4AppDelegate*appDelegate=[[UIApplicationsharedApplication]delegate];
  21. NSManagedObjectContext*context=[appDelegatemanagedObjectContext];
  22. NSError*error;
  23. for(inti=1;i<=4;i++){
  24. NSString*fieldName=[NSStringstringWithFormat:@"field%d",i];
  25. UITextField*theField=[selfvalueForKey:fieldName];
  27. //创建提取请求
  28. NSFetchRequest*request=[[NSFetchRequestalloc]init];
  29. //创建实体描述并关联到请求
  30. NSEntityDescription*entityDescription=[NSEntityDescriptionentityForName:@"Line"
  31. inManagedObjectContext:context];
  32. [requestsetEntity:entityDescription];
  34. //设置检索数据的条件
  35. NSPredicate*pred=[NSPredicatepredicateWithFormat:@"(lineNum=%d)",i];
  36. [requestsetPredicate:pred];
  38. NSManagedObject*theLine=nil;
  39. ////检查是否返回了标准匹配的对象，如果有则加载它，如果没有则创建一个新的托管对象来保存此字段的文本
  40. NSArray*objects=[contextexecuteFetchRequest:requesterror:&error];
  41. if(!objects){
  42. NSLog(@"Therewasanerror");
  43. }
  44. //if(objects.count>0){
  45. //theLine=[objectsobjectAtIndex:0];
  46. //}else{
  47. //创建一个新的托管对象来保存此字段的文本
  48. theLine=[NSEntityDescriptioninsertNewObjectForEntityForName:@"Line"
  49. inManagedObjectContext:context];
  50. [theLinesetValue:[NSNumbernumberWithInt:i]forKey:@"lineNum"];
  51. [theLinesetValue:theField.textforKey:@"lineText"];
  52. //}
  53. [requestrelease];
  54. }
  55. //通知上下文保存更改
  56. [contextsave:&error];
  58. }
  60. //Thedesignatedinitializer.OverrideifyoucreatethecontrollerprogrammaticallyandwanttoperformcustomizationthatisnotappropriateforviewDidLoad.
  61. /*
  62. -(id)initWithNibName:(NSString*)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil{
  63. self=[superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];
  64. if(self){
  65. //Custominitialization.
  66. }
  67. returnself;
  68. }
  69. */
  72. //ImplementviewDidLoadtodoadditionalsetupafterloadingtheview,typicallyfromanib.
  73. -(void)viewDidLoad{
  74. Persistence4AppDelegate*appDelegate=[[UIApplicationsharedApplication]delegate];
  76. NSManagedObjectContext*context=[appDelegatemanagedObjectContext];
  77. //创建一个实体描述
  78. NSEntityDescription*entityDescription=[NSEntityDescriptionentityForName:@"Line"inManagedObjectContext:context];
  79. //创建一个请求，用于提取对象
  80. NSFetchRequest*request=[[NSFetchRequestalloc]init];
  81. [requestsetEntity:entityDescription];
  83. //检索对象
  84. NSError*error;
  85. NSArray*objects=[contextexecuteFetchRequest:requesterror:&error];
  86. if(!objects){
  87. NSLog(@"Therewasanerror!");
  88. }
  89. for(NSManagedObject*objinobjects){
  90. NSNumber*lineNum=[objvalueForKey:@"lineNum"];
  91. NSString*lineText=[objvalueForKey:@"lineText"];
  92. NSString*fieldName=[NSStringstringWithFormat:@"field%d",[lineNumintegerValue]];
  93. UITextField*textField=[selfvalueForKey:fieldName];
  94. textField.text=lineText;
  95. }
  96. [requestrelease];
  98. UIApplication*app=[UIApplicationsharedApplication];
  99. [[NSNotificationCenterdefaultCenter]addObserver:self
  100. selector:@selector(applicationWillResignActive:)
  101. name:UIApplicationWillResignActiveNotification
  102. object:app];
  103. [superviewDidLoad];
  104. }
  106. /*
  107. //Overridetoalloworientationsotherthanthedefaultportraitorientation.
  108. -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
  109. //ReturnYESforsupportedorientations.
  110. return(interfaceOrientation==UIInterfaceOrientationPortrait);
  111. }
  112. */
  114. -(void)didReceiveMemoryWarning{
  115. //Releasestheviewifitdoesn'thaveasuperview.
  116. [superdidReceiveMemoryWarning];
  118. //Releaseanycacheddata,images,etc.thataren'tinuse.
  119. }
  121. -(void)viewDidUnload{
  122. self.field1=nil;
  123. self.field2=nil;
  124. self.field3=nil;
  125. self.field4=nil;
  126. [superviewDidUnload];
  127. }
  130. -(void)dealloc{
  131. [field1release];
  132. [field2release];
  133. [field3release];
  134. [field4release];
  135. [superdealloc];
  136. }
  140. @end

5、AppSettings

[cpp]view plaincopy
  1. NSUserDefaults*defaults=[NSUserDefaultsstandardUserDefaults];

===================================================================================

===================================================================================

6、普通文件存储

这种方式即自己将数据通过IO保存到文件，或从文件读取。


声明：此篇所有代码来自《Iphone4与IPad开发基础教程》

from:http://blog.csdn.net/liuhongwei123888/article/details/6841338

属性列表

对象归档

SQLite3

CoreData

AppSettings

普通文件存储

1、属性列表

[cpp]view plaincopy
  1. //
  2. //Persistence1ViewController.h
  3. //Persistence1
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<UIKit/UIKit.h>
  10. #definekFilename@"data.plist"
  12. @interfacePersistence1ViewController:UIViewController{
  13. UITextField*filed1;
  14. UITextField*field2;
  15. UITextField*field3;
  16. UITextField*field4;
  17. }
  18. @property(nonatomic,retain)IBOutletUITextField*field1;
  19. @property(nonatomic,retain)IBOutletUITextField*field2;
  20. @property(nonatomic,retain)IBOutletUITextField*field3;
  21. @property(nonatomic,retain)IBOutletUITextField*field4;
  23. -(NSString*)dataFilePath;
  24. -(void)applicationWillResignActive:(NSNotification*)notification;
  26. @end

[cpp]view plaincopy
  1. //
  2. //Persistence1ViewController.m
  3. //Persistence1
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"Persistence1ViewController.h"
  11. @implementationPersistence1ViewController
  12. @synthesizefield1;
  13. @synthesizefield2;
  14. @synthesizefield3;
  15. @synthesizefield4;
  17. //数据文件的完整路径
  18. -(NSString*)dataFilePath{
  19. //检索Documents目录路径。第二个参数表示将搜索限制在我们的应用程序沙盒中
  20. NSArray*paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
  21. //每个应用程序只有一个Documents目录
  22. NSString*documentsDirectory=[pathsobjectAtIndex:0];
  23. //创建文件名
  24. return[documentsDirectorystringByAppendingPathComponent:kFilename];
  25. }
  27. //应用程序退出时，将数据保存到属性列表文件
  28. -(void)applicationWillResignActive:(NSNotification*)notification{
  29. NSMutableArray*array=[[NSMutableArrayalloc]init];
  30. [arrayaddObject:field1.text];
  31. [arrayaddObject:field2.text];
  32. [arrayaddObject:field3.text];
  33. [arrayaddObject:field4.text];
  34. [arraywriteToFile:[selfdataFilePath]atomically:YES];
  35. [arrayrelease];
  36. }
  38. /*
  39. //Thedesignatedinitializer.Overridetoperformsetupthatisrequiredbeforetheviewisloaded.
  40. -(id)initWithNibName:(NSString*)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil{
  41. self=[superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];
  42. if(self){
  43. //Custominitialization
  44. }
  45. returnself;
  46. }
  47. */
  49. /*
  50. //ImplementloadViewtocreateaviewhierarchyprogrammatically,withoutusinganib.
  51. -(void)loadView{
  52. }
  53. */
  57. //ImplementviewDidLoadtodoadditionalsetupafterloadingtheview,typicallyfromanib.
  58. -(void)viewDidLoad{
  59. [superviewDidLoad];
  60. NSString*filePath=[selfdataFilePath];
  61. //检查数据文件是否存在
  62. if([[NSFileManagerdefaultManager]fileExistsAtPath:filePath]){
  63. NSArray*array=[[NSArrayalloc]initWithContentsOfFile:filePath];
  64. field1.text=[arrayobjectAtIndex:0];
  65. field2.text=[arrayobjectAtIndex:1];
  66. field3.text=[arrayobjectAtIndex:2];
  67. field4.text=[arrayobjectAtIndex:3];
  68. [arrayrelease];
  69. }
  70. UIApplication*app=[UIApplicationsharedApplication];
  71. [[NSNotificationCenterdefaultCenter]addObserver:self
  72. selector:@selector(applicationWillResignActive:)
  73. name:UIApplicationWillResignActiveNotification
  74. object:app];
  75. [superviewDidLoad];
  76. }
  79. /*
  80. //Overridetoalloworientationsotherthanthedefaultportraitorientation.
  81. -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
  82. //ReturnYESforsupportedorientations
  83. return(interfaceOrientation==UIInterfaceOrientationPortrait);
  84. }
  85. */
  87. -(void)didReceiveMemoryWarning{
  88. //Releasestheviewifitdoesn'thaveasuperview.
  89. [superdidReceiveMemoryWarning];
  91. //Releaseanycacheddata,images,etcthataren'tinuse.
  92. }
  94. -(void)viewDidUnload{
  95. self.field1=nil;
  96. self.field2=nil;
  97. self.field3=nil;
  98. self.field4=nil;
  99. [superviewDidUnload];
  100. }
  103. -(void)dealloc{
  104. [field1release];
  105. [field2release];
  106. [field3release];
  107. [field4release];
  108. [superdealloc];
  109. }
  111. @end

===================================================================================

===================================================================================

2、对象归档

[cpp]view plaincopy
  1. //
  2. //Fourlines.h
  3. //Persistence2
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<Foundation/Foundation.h>
  11. @interfaceFourlines:NSObject<NSCoding,NSCopying>{
  12. NSString*field1;
  13. NSString*field2;
  14. NSString*field3;
  15. NSString*field4;
  16. }
  17. @property(nonatomic,retain)NSString*field1;
  18. @property(nonatomic,retain)NSString*field2;
  19. @property(nonatomic,retain)NSString*field3;
  20. @property(nonatomic,retain)NSString*field4;
  23. @end

[cpp]view plaincopy
  1. //
  2. //Fourlines.m
  3. //Persistence2
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"Fourlines.h"
  11. #definekField1Key@"Field1"
  12. #definekField2Key@"Field2"
  13. #definekField3Key@"Field3"
  14. #definekField4Key@"Field4"
  16. @implementationFourlines
  17. @synthesizefield1;
  18. @synthesizefield2;
  19. @synthesizefield3;
  20. @synthesizefield4;
  22. #pragmamarkNSCoding
  23. -(void)encodeWithCoder:(NSCoder*)aCoder{
  24. [aCoderencodeObject:field1forKey:kField1Key];
  25. [aCoderencodeObject:field2forKey:kField2Key];
  26. [aCoderencodeObject:field3forKey:kField3Key];
  27. [aCoderencodeObject:field4forKey:kField4Key];
  28. }
  30. -(id)initWithCoder:(NSCoder*)aDecoder{
  31. if(self=[superinit]){
  32. field1=[[aDecoderdecodeObjectForKey:kField1Key]retain];
  33. field2=[[aDecoderdecodeObjectForKey:kField2Key]retain];
  34. field3=[[aDecoderdecodeObjectForKey:kField3Key]retain];
  35. field4=[[aDecoderdecodeObjectForKey:kField4Key]retain];
  36. }
  37. returnself;
  38. }
  40. #pragmamark-
  41. #pragmamarkNSCopying
  42. -(id)copyWithZone:(NSZone*)zone{
  43. Fourlines*copy=[[[selfclass]allocWithZone:zone]init];
  44. copy.field1=[[self.field1copyWithZone:zone]autorelease];
  45. copy.field2=[[self.field2copyWithZone:zone]autorelease];
  46. copy.field3=[[self.field3copyWithZone:zone]autorelease];
  47. copy.field4=[[self.field4copyWithZone:zone]autorelease];
  48. returncopy;
  49. }
  50. @end

[cpp]view plaincopy
  1. //
  2. //Persistence2ViewController.h
  3. //Persistence2
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<UIKit/UIKit.h>
  10. #definekFilename@"archive"
  11. #definekDataKey@"Data"
  13. @interfacePersistence2ViewController:UIViewController{
  14. UITextField*filed1;
  15. UITextField*field2;
  16. UITextField*field3;
  17. UITextField*field4;
  18. }
  19. @property(nonatomic,retain)IBOutletUITextField*field1;
  20. @property(nonatomic,retain)IBOutletUITextField*field2;
  21. @property(nonatomic,retain)IBOutletUITextField*field3;
  22. @property(nonatomic,retain)IBOutletUITextField*field4;
  24. -(NSString*)dataFilePath;
  25. -(void)applicationWillResignActive:(NSNotification*)notification;
  27. @end

[cpp]view plaincopy
  1. //
  2. //Persistence2ViewController.m
  3. //Persistence2
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"Persistence2ViewController.h"
  10. #import"Fourlines.h"
  12. @implementationPersistence2ViewController
  13. @synthesizefield1;
  14. @synthesizefield2;
  15. @synthesizefield3;
  16. @synthesizefield4;
  18. //数据文件的完整路径
  19. -(NSString*)dataFilePath{
  20. //检索Documents目录路径。第二个参数表示将搜索限制在我们的应用程序沙盒中
  21. NSArray*paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
  22. //每个应用程序只有一个Documents目录
  23. NSString*documentsDirectory=[pathsobjectAtIndex:0];
  24. //创建文件名
  25. return[documentsDirectorystringByAppendingPathComponent:kFilename];
  26. }
  28. //应用程序退出时，将数据保存到属性列表文件
  29. -(void)applicationWillResignActive:(NSNotification*)notification{
  30. Fourlines*fourlines=[[Fourlinesalloc]init];
  31. fourlines.field1=field1.text;
  32. fourlines.field2=field2.text;
  33. fourlines.field3=field3.text;
  34. fourlines.field4=field4.text;
  36. NSMutableData*data=[[NSMutableDataalloc]init];//用于存储编码的数据
  37. NSKeyedArchiver*archiver=[[NSKeyedArchiveralloc]initForWritingWithMutableData:data];
  39. [archiverencodeObject:fourlinesforKey:kDataKey];
  40. [archiverfinishEncoding];
  41. [datawriteToFile:[selfdataFilePath]atomically:YES];
  43. [fourlinesrelease];
  44. [archiverrelease];
  45. [datarelease];
  46. }
  48. /*
  49. //Thedesignatedinitializer.Overridetoperformsetupthatisrequiredbeforetheviewisloaded.
  50. -(id)initWithNibName:(NSString*)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil{
  51. self=[superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];
  52. if(self){
  53. //Custominitialization
  54. }
  55. returnself;
  56. }
  57. */
  59. /*
  60. //ImplementloadViewtocreateaviewhierarchyprogrammatically,withoutusinganib.
  61. -(void)loadView{
  62. }
  63. */
  67. //ImplementviewDidLoadtodoadditionalsetupafterloadingtheview,typicallyfromanib.
  68. -(void)viewDidLoad{
  69. [superviewDidLoad];
  70. NSString*filePath=[selfdataFilePath];
  71. //检查数据文件是否存在
  72. if([[NSFileManagerdefaultManager]fileExistsAtPath:filePath]){
  74. //从文件获取用于解码的数据
  75. NSData*data=[[NSMutableDataalloc]initWithContentsOfFile:[selfdataFilePath]];
  76. NSKeyedUnarchiver*unarchiver=[[NSKeyedUnarchiveralloc]initForReadingWithData:data];
  78. Fourlines*fourlines=[unarchiverdecodeObjectForKey:kDataKey];
  79. [unarchiverfinishDecoding];
  81. field1.text=fourlines.field1;
  82. field2.text=fourlines.field2;
  83. field3.text=fourlines.field3;
  84. field4.text=fourlines.field4;
  86. [unarchiverrelease];
  87. [datarelease];
  88. }
  89. UIApplication*app=[UIApplicationsharedApplication];
  90. [[NSNotificationCenterdefaultCenter]addObserver:self
  91. selector:@selector(applicationWillResignActive:)
  92. name:UIApplicationWillResignActiveNotification
  93. object:app];
  94. [superviewDidLoad];
  95. }
  98. /*
  99. //Overridetoalloworientationsotherthanthedefaultportraitorientation.
  100. -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
  101. //ReturnYESforsupportedorientations
  102. return(interfaceOrientation==UIInterfaceOrientationPortrait);
  103. }
  104. */
  106. -(void)didReceiveMemoryWarning{
  107. //Releasestheviewifitdoesn'thaveasuperview.
  108. [superdidReceiveMemoryWarning];
  110. //Releaseanycacheddata,images,etcthataren'tinuse.
  111. }
  113. -(void)viewDidUnload{
  114. self.field1=nil;
  115. self.field2=nil;
  116. self.field3=nil;
  117. self.field4=nil;
  118. [superviewDidUnload];
  119. }
  122. -(void)dealloc{
  123. [field1release];
  124. [field2release];
  125. [field3release];
  126. [field4release];
  127. [superdealloc];
  128. }
  129. @end


===================================================================================

===================================================================================


3、SQLite

[cpp]view plaincopy
  1. //
  2. //Persistence3ViewController.h
  3. //Persistence3
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<UIKit/UIKit.h>
  10. #definekFilename@"data.sqlite3"
  12. @interfacePersistence3ViewController:UIViewController{
  13. UITextField*filed1;
  14. UITextField*field2;
  15. UITextField*field3;
  16. UITextField*field4;
  17. }
  18. @property(nonatomic,retain)IBOutletUITextField*field1;
  19. @property(nonatomic,retain)IBOutletUITextField*field2;
  20. @property(nonatomic,retain)IBOutletUITextField*field3;
  21. @property(nonatomic,retain)IBOutletUITextField*field4;
  23. -(NSString*)dataFilePath;
  24. -(void)applicationWillResignActive:(NSNotification*)notification;
  25. @end

[cpp]view plaincopy
  1. //
  2. //Persistence3ViewController.m
  3. //Persistence3
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"Persistence3ViewController.h"
  10. #import<sqlite3.h>
  12. @implementationPersistence3ViewController
  13. @synthesizefield1;
  14. @synthesizefield2;
  15. @synthesizefield3;
  16. @synthesizefield4;
  18. //数据文件的完整路径
  19. -(NSString*)dataFilePath{
  20. //检索Documents目录路径。第二个参数表示将搜索限制在我们的应用程序沙盒中
  21. NSArray*paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
  22. //每个应用程序只有一个Documents目录
  23. NSString*documentsDirectory=[pathsobjectAtIndex:0];
  24. //创建文件名
  25. return[documentsDirectorystringByAppendingPathComponent:kFilename];
  26. }
  28. //应用程序退出时，将数据保存到属性列表文件
  29. -(void)applicationWillResignActive:(NSNotification*)notification{
  30. sqlite3*database;
  31. if(sqlite3_open([[selfdataFilePath]UTF8String],&database)!=SQLITE_OK){
  32. sqlite3_close(database);
  33. NSAssert(0,@"Failedtoopendatabase");
  34. }
  36. for(inti=1;i<=4;i++){
  37. NSString*fieldname=[[NSStringalloc]initWithFormat:@"field%d",i];
  38. UITextField*field=[selfvalueForKey:fieldname];
  39. [fieldnamerelease];
  41. char*update="INSERTORREPLACEINTOFIELDS(ROW,FIELD_DATA)VALUES(?,?);";
  42. sqlite3_stmt*stmt;
  43. //将SQL语句编译为sqlite内部一个结构体(sqlite3_stmt),类似javaJDBC的PreparedStatement预编译
  44. if(sqlite3_prepare_v2(database,update,-1,&stmt,nil)==SQLITE_OK){
  45. //在bind参数的时候,参数列表的index从1开始,而取出数据的时候,列的index是从0开始
  46. sqlite3_bind_int(stmt,1,i);
  47. sqlite3_bind_text(stmt,2,[field.textUTF8String],-1,NULL);
  48. }else{
  49. NSAssert(0,@"Error:Failedtopreparestatemen");
  50. }
  51. //执行SQL文，获取结果
  52. intresult=sqlite3_step(stmt);
  53. if(result!=SQLITE_DONE){
  54. NSAssert1(0,@"Errorupdatingtable:%d",result);
  55. }
  56. //释放stmt占用的内存(sqlite3_prepare_v2()分配的）
  57. sqlite3_finalize(stmt);
  58. }
  59. sqlite3_close(database);
  60. }
  62. /*
  63. //Thedesignatedinitializer.Overridetoperformsetupthatisrequiredbeforetheviewisloaded.
  64. -(id)initWithNibName:(NSString*)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil{
  65. self=[superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];
  66. if(self){
  67. //Custominitialization
  68. }
  69. returnself;
  70. }
  71. */
  73. /*
  74. //ImplementloadViewtocreateaviewhierarchyprogrammatically,withoutusinganib.
  75. -(void)loadView{
  76. }
  77. */
  81. //ImplementviewDidLoadtodoadditionalsetupafterloadingtheview,typicallyfromanib.
  82. -(void)viewDidLoad{
  83. [superviewDidLoad];
  84. NSString*filePath=[selfdataFilePath];
  85. //检查数据文件是否存在
  86. if([[NSFileManagerdefaultManager]fileExistsAtPath:filePath]){
  87. //打开数据库
  88. sqlite3*database;
  89. if(sqlite3_open([filePathUTF8String],&database)!=SQLITE_OK){
  90. sqlite3_close(database);
  91. NSAssert(0,@"Failedtoopendatabase");
  92. }
  94. //创建表
  95. char*errorMsg;
  96. NSString*createSQL=
  97. @"CREATETABLEIFNOTEXISTSFIELDS(ROWINTEGERPRIMARYKEY,FIELD_DATATEXT);";
  98. if(sqlite3_exec(database,[createSQLUTF8String],NULL,NULL,&errorMsg)!=SQLITE_OK){
  99. sqlite3_close(database);
  100. NSAssert(0,@"Errorcreatingtable:%s",errorMsg);
  101. }
  103. //查询
  104. NSString*query=@"SELECTROW,FIELD_DATAFROMFIELDSORDERBYROW";
  105. sqlite3_stmt*statement;
  106. //设置nByte可以加速操作
  107. if(sqlite3_prepare_v2(database,[queryUTF8String],-1,&statement,nil)==SQLITE_OK){
  108. while(sqlite3_step(statement)==SQLITE_ROW){//返回每一行
  109. introw=sqlite3_column_int(statement,0);
  110. char*rowData=(char*)sqlite3_column_text(statement,1);
  112. NSString*fieldName=[[NSStringalloc]initWithFormat:@"field%d",row];
  113. NSString*fieldValue=[[NSStringalloc]initWithUTF8String:rowData];
  115. UITextField*field=[selfvalueForKey:fieldName];
  116. field.text=fieldValue;
  118. [fieldNamerelease];
  119. [fieldValuerelease];
  120. }
  121. //释放statement占用的内存(sqlite3_prepare()分配的）
  122. sqlite3_finalize(statement);
  123. }
  124. sqlite3_close(database);
  125. }
  128. UIApplication*app=[UIApplicationsharedApplication];
  129. [[NSNotificationCenterdefaultCenter]addObserver:self
  130. selector:@selector(applicationWillResignActive:)
  131. name:UIApplicationWillResignActiveNotification
  132. object:app];
  133. [superviewDidLoad];
  134. }
  137. /*
  138. //Overridetoalloworientationsotherthanthedefaultportraitorientation.
  139. -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
  140. //ReturnYESforsupportedorientations
  141. return(interfaceOrientation==UIInterfaceOrientationPortrait);
  142. }
  143. */
  145. -(void)didReceiveMemoryWarning{
  146. //Releasestheviewifitdoesn'thaveasuperview.
  147. [superdidReceiveMemoryWarning];
  149. //Releaseanycacheddata,images,etcthataren'tinuse.
  150. }
  152. -(void)viewDidUnload{
  153. self.field1=nil;
  154. self.field2=nil;
  155. self.field3=nil;
  156. self.field4=nil;
  157. [superviewDidUnload];
  158. }
  161. -(void)dealloc{
  162. [field1release];
  163. [field2release];
  164. [field3release];
  165. [field4release];
  166. [superdealloc];
  167. }
  169. @end

===================================================================================

===================================================================================

4、Core Data

[cpp]view plaincopy
  1. //
  2. //PersistenceViewController.h
  3. //Persistence4
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import<UIKit/UIKit.h>
  12. @interfacePersistenceViewController:UIViewController{
  13. UITextField*filed1;
  14. UITextField*field2;
  15. UITextField*field3;
  16. UITextField*field4;
  17. }
  18. @property(nonatomic,retain)IBOutletUITextField*field1;
  19. @property(nonatomic,retain)IBOutletUITextField*field2;
  20. @property(nonatomic,retain)IBOutletUITextField*field3;
  21. @property(nonatomic,retain)IBOutletUITextField*field4;
  23. @end

[cpp]view plaincopy
  1. //
  2. //PersistenceViewController.m
  3. //Persistence4
  4. //
  5. //Createdbyliulavyon11-10-3.
  6. //Copyright2011__MyCompanyName__.Allrightsreserved.
  7. //
  9. #import"PersistenceViewController.h"
  10. #import"Persistence4AppDelegate.h"
  12. @implementationPersistenceViewController
  13. @synthesizefield1;
  14. @synthesizefield2;
  15. @synthesizefield3;
  16. @synthesizefield4;
  19. -(void)applicationWillResignActive:(NSNotification*)notification{
  20. Persistence4AppDelegate*appDelegate=[[UIApplicationsharedApplication]delegate];
  21. NSManagedObjectContext*context=[appDelegatemanagedObjectContext];
  22. NSError*error;
  23. for(inti=1;i<=4;i++){
  24. NSString*fieldName=[NSStringstringWithFormat:@"field%d",i];
  25. UITextField*theField=[selfvalueForKey:fieldName];
  27. //创建提取请求
  28. NSFetchRequest*request=[[NSFetchRequestalloc]init];
  29. //创建实体描述并关联到请求
  30. NSEntityDescription*entityDescription=[NSEntityDescriptionentityForName:@"Line"
  31. inManagedObjectContext:context];
  32. [requestsetEntity:entityDescription];
  34. //设置检索数据的条件
  35. NSPredicate*pred=[NSPredicatepredicateWithFormat:@"(lineNum=%d)",i];
  36. [requestsetPredicate:pred];
  38. NSManagedObject*theLine=nil;
  39. ////检查是否返回了标准匹配的对象，如果有则加载它，如果没有则创建一个新的托管对象来保存此字段的文本
  40. NSArray*objects=[contextexecuteFetchRequest:requesterror:&error];
  41. if(!objects){
  42. NSLog(@"Therewasanerror");
  43. }
  44. //if(objects.count>0){
  45. //theLine=[objectsobjectAtIndex:0];
  46. //}else{
  47. //创建一个新的托管对象来保存此字段的文本
  48. theLine=[NSEntityDescriptioninsertNewObjectForEntityForName:@"Line"
  49. inManagedObjectContext:context];
  50. [theLinesetValue:[NSNumbernumberWithInt:i]forKey:@"lineNum"];
  51. [theLinesetValue:theField.textforKey:@"lineText"];
  52. //}
  53. [requestrelease];
  54. }
  55. //通知上下文保存更改
  56. [contextsave:&error];
  58. }
  60. //Thedesignatedinitializer.OverrideifyoucreatethecontrollerprogrammaticallyandwanttoperformcustomizationthatisnotappropriateforviewDidLoad.
  61. /*
  62. -(id)initWithNibName:(NSString*)nibNameOrNilbundle:(NSBundle*)nibBundleOrNil{
  63. self=[superinitWithNibName:nibNameOrNilbundle:nibBundleOrNil];
  64. if(self){
  65. //Custominitialization.
  66. }
  67. returnself;
  68. }
  69. */
  72. //ImplementviewDidLoadtodoadditionalsetupafterloadingtheview,typicallyfromanib.
  73. -(void)viewDidLoad{
  74. Persistence4AppDelegate*appDelegate=[[UIApplicationsharedApplication]delegate];
  76. NSManagedObjectContext*context=[appDelegatemanagedObjectContext];
  77. //创建一个实体描述
  78. NSEntityDescription*entityDescription=[NSEntityDescriptionentityForName:@"Line"inManagedObjectContext:context];
  79. //创建一个请求，用于提取对象
  80. NSFetchRequest*request=[[NSFetchRequestalloc]init];
  81. [requestsetEntity:entityDescription];
  83. //检索对象
  84. NSError*error;
  85. NSArray*objects=[contextexecuteFetchRequest:requesterror:&error];
  86. if(!objects){
  87. NSLog(@"Therewasanerror!");
  88. }
  89. for(NSManagedObject*objinobjects){
  90. NSNumber*lineNum=[objvalueForKey:@"lineNum"];
  91. NSString*lineText=[objvalueForKey:@"lineText"];
  92. NSString*fieldName=[NSStringstringWithFormat:@"field%d",[lineNumintegerValue]];
  93. UITextField*textField=[selfvalueForKey:fieldName];
  94. textField.text=lineText;
  95. }
  96. [requestrelease];
  98. UIApplication*app=[UIApplicationsharedApplication];
  99. [[NSNotificationCenterdefaultCenter]addObserver:self
  100. selector:@selector(applicationWillResignActive:)
  101. name:UIApplicationWillResignActiveNotification
  102. object:app];
  103. [superviewDidLoad];
  104. }
  106. /*
  107. //Overridetoalloworientationsotherthanthedefaultportraitorientation.
  108. -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
  109. //ReturnYESforsupportedorientations.
  110. return(interfaceOrientation==UIInterfaceOrientationPortrait);
  111. }
  112. */
  114. -(void)didReceiveMemoryWarning{
  115. //Releasestheviewifitdoesn'thaveasuperview.
  116. [superdidReceiveMemoryWarning];
  118. //Releaseanycacheddata,images,etc.thataren'tinuse.
  119. }
  121. -(void)viewDidUnload{
  122. self.field1=nil;
  123. self.field2=nil;
  124. self.field3=nil;
  125. self.field4=nil;
  126. [superviewDidUnload];
  127. }
  130. -(void)dealloc{
  131. [field1release];
  132. [field2release];
  133. [field3release];
  134. [field4release];
  135. [superdealloc];
  136. }
  140. @end

5、AppSettings

[cpp]view plaincopy
  1. NSUserDefaults*defaults=[NSUserDefaultsstandardUserDefaults];

===================================================================================

===================================================================================

6、普通文件存储

这种方式即自己将数据通过IO保存到文件，或从文件读取。


声明：此篇所有代码来自《Iphone4与IPad开发基础教程》

from:http://blog.csdn.net/liuhongwei123888/article/details/6841338
分享到：
| Java程序员必看的15本书：Java架构师之路
评论
发表评论

您还没有登录,请您登录后再发表评论

相关推荐

Magicbox
Global site tag (gtag.js) - Google Analytics