Android 程式开发：（四）使用Intent调用“内置”应用 —— 4.3配置Intent-Filter

我们已经知道，一个activity通过使用Intent对象调用另外一个activity。为了能让其他activity做出回应，还需要在AndroidManifest.xml中配置<intent-filter>元素，同时指定action和category。例如：

            <intent-filter >
                <action android:name="net.learn2develop.SecondActivity" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>

1.新建一个工程，创建一个类：MyBrowserActivity.java。同时在res/layout中创建一个xml文件：brwoser.xml。

2.AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="net.learn2develop.Intents"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="14" />
    <uses-permission android:name="android.permission.CALL_PHONE"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:label="@string/app_name"
            android:name=".IntentsActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        
              
        <activity android:name=".MyBrowserActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <action android:name="net.learn2develop.MyBrowser" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:scheme="http" />
            </intent-filter>
        </activity>
        
            
    </application>

</manifest>

3.在main.xml中添加一个Button元素。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/btn_launchMyBrowser"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="onClickLaunchMyBrowser"
        android:text="Launch My Browser" />

</LinearLayout>

4.IntentsActivity.java

package net.learn2develop.Intents;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;

public class IntentsActivity extends Activity {

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
	}
	
	public void onClickLaunchMyBrowser(View view) {
		Intent i = new Intent("net.learn2develop.MyBrowser");
                i.setData(Uri.parse("http://www.amazon.com"));
                startActivity(i);		
	}
	
}

5.browser.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <WebView
        android:id="@+id/WebView01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

6.MyBorwserActivity.java

package net.learn2develop.Intents;

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MyBrowserActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.browser);

        Uri url = getIntent().getData();
        WebView webView = (WebView) findViewById(R.id.WebView01);
        webView.setWebViewClient(new Callback());
        webView.loadUrl(url.toString());
    }

    private class Callback extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            return (false);
        }
    }
}

7.调试。

8.点击“Launch my Browser”按钮，将会看到一个新的activity，并且显示了Amazon.com网站的网页。