android实现多列显示的下拉列表框-Spinner

先上张效果图：

严格来说，这并不是一个下拉列表，只不过实现的效果很像是下拉列表

实现原理：

该下拉列表其实是一个AlertDialog.Builder，给它设置了一个以LinearLayout布局的View。该View内使用了一个GridView组件，

代码：

package yyy.testandroid9;
	private Intent intent;
	private int index = 0;
	private SharedPreferences preferences;
	private File file;
	private Spinner spinner;
	private GridView gridView;
	private LinearLayout layout;
	private Builder builder;
	private AlertDialog dialog;
	private MyAdapter adapter;

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

		LayoutInflater inflater = LayoutInflater.from(this);
		layout = (LinearLayout) inflater.inflate(R.layout.bank_grid, null);
		gridView = (GridView) layout.findViewById(R.id.grid);
		adapter = new MyAdapter(this);
		gridView.setAdapter(adapter);
		button1 = (Button) findViewById(R.id.button1);
		button2 = (Button) findViewById(R.id.button2);
		textView = (TextView) findViewById(R.id.textview);
		builder = new Builder(TestAndroid9Activity.this);
		builder.setView(layout);
	    
		
		button1.setOnClickListener(new OnClickListener() {
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				 if(dialog == null){
					 dialog = builder.show();
				 }
				 dialog.show();
				 
			}
		});
		
		
		gridView.setOnItemClickListener(new OnItemClickListener() {
			public void onItemClick(AdapterView<?> arg0, View arg1, int position,
					long arg3) {
				// TODO Auto-generated method stub
				button1.setText(getResources().getStringArray(R.array.city)[position]);
				dialog.dismiss();
				adapter.map.put(index, false);
				adapter.map.put(position, true);
				index = position;
				adapter.notifyDataSetChanged();
			}
		});
		
	}

	private class MyAdapter extends BaseAdapter{
		private Context context;
		private String[] citys;
		private LayoutInflater inflater;
        public HashMap<Integer, Boolean> map;
		
		public MyAdapter(Context context) {
			super();
			this.context = context;
			citys = context.getResources().getStringArray(R.array.city);
			inflater = LayoutInflater.from(context);
			map = new HashMap<Integer, Boolean>();
			for(int i=0;i<citys.length;i++){
				map.put(i, false);
			}
		}

		public int getCount() {
			// TODO Auto-generated method stub
			return citys.length;
		}

		public Object getItem(int position) {
			// TODO Auto-generated method stub
			return null;
		}

		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		public View getView(int position, View view, ViewGroup parent) {
			// TODO Auto-generated method stub
			if(view == null){
				view = inflater.inflate(R.layout.bank_item, null);
			}
			TextView textView = (TextView) view.findViewById(R.id.list_text);
			RadioButton radioButton = (RadioButton) view.findViewById(R.id.radiobutton);
			radioButton.setChecked(map.get(position));
			textView.setText(citys[position]);
			return view;
		}
	}

bank_grid.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"
    android:padding="20dp" 
    android:background="#ffffff"
    android:id="@+id/grid_layout">

	
	 
	<GridView	
	    android:id="@+id/grid"
  			android:layout_width="fill_parent"
			android:layout_height="fill_parent"
			android:verticalSpacing="20px"
			android:horizontalSpacing="10px"
			android:numColumns="4"
			android:scrollbars="vertical"
			android:layout_margin="10dp"/>
	
</LinearLayout>

bank_item.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:background="#ffffff"
     >

     <RadioButton
        android:id="@+id/radiobutton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginRight="15dp"
        android:focusable="false"
        android:clickable="false"
        android:focusableInTouchMode="false"
        />
    <TextView
        android:id="@+id/list_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#000000" 
        android:layout_gravity="center_vertical"/>

</LinearLayout>