android 實現懸浮控件

package com.example.desktoptxt;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.PixelFormat;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.WindowManager.LayoutParams;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

/**
 * 實現桌面View
 * 
 * 1)將要顯示在桌面的view,通過WindowManager.addView，掛在到WindowManager下;	要注意，WindowManager對象來源，源碼裡解釋。
 * 	並且配置好view的WindowManager.LayoutParams
 * 		1-1)WindowManager.LayoutParams.type 設置為 WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY;時，
 * 			桌面UI不可以直接setOnClickListener()，該View的onTouchEvent()函數也無效了
 * 			設置為WindowManager.LayoutParams.TYPE_SYSTEM_ALERT(2003)或者WindowManager.LayoutParams.TYPE_PHONE2002才有效。
 * 		1-2)WindowManager.LayoutParams.flag 設置為LayoutParams.FLAG_NOT_TOUCH_MODAL | LayoutParams.FLAG_NOT_FOCUSABLE
 * 			如果設置了WindowManager.LayoutParams.type為2002,2003；那麼flag不設置為這兩個flag的話，那麼其他組件就無法獲得touch和focus事件了。
 * 			設置了該兩個屬性之後就大家都可以獲得Touch和Focus事件
 * 
 * 2)androidManifest裡申明權限
 * 	
 * 
 * 
 * @author jiese1990
 *
 */
public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		TextView tv = new TextView(this);  
		tv.setText("this is a desktop text");
		tv.setTextColor(0xFFFF0000);
		tv.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				Toast.makeText(MainActivity.this, "click", Toast.LENGTH_SHORT).show();
			}
		});
		tv.setBackgroundColor(0xFF00000);
		initDestopText(tv);
		
	}

	private void initDestopText(View childView){

		//直接通過Activity獲取的 WindowManager，在act退出時，桌面組件也將退出。
//		WindowManager wm = (WindowManager)getSystemService(WINDOW_SERVICE); 
		//一定要通過getApplicationContext()獲取WindowManager,這種情況下，當Application終止後，懸浮控件才會被退出
		WindowManager wm = (WindowManager)getApplicationContext().getSystemService(WINDOW_SERVICE); 
		
		
		WindowManager.LayoutParams params = new WindowManager.LayoutParams();  
//		params.type = WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY;  	//如果設置為
		params.type = WindowManager.LayoutParams.TYPE_PHONE; // 
		params.flags = LayoutParams.FLAG_NOT_TOUCH_MODAL | LayoutParams.FLAG_NOT_FOCUSABLE;
		params.width = WindowManager.LayoutParams.WRAP_CONTENT;  
		params.height = WindowManager.LayoutParams.WRAP_CONTENT;  
		wm.addView(childView, params);  
	}


}