顶级浮动窗口

窗口一直浮在手机任何应用上

package test.floating;

import android.app.Activity;
import android.os.Bundle;
import android.view.WindowManager;
import android.widget.Button;

public class MyFloatViewActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
//         setContentView(R.layout.main);
         Button bb=new Button(getApplicationContext());
         bb.setText("测试浮动窗口");
         WindowManager wm=(WindowManager)getApplicationContext().getSystemService("window");
         WindowManager.LayoutParams wmParams = new WindowManager.LayoutParams();

         /**
          *以下都是WindowManager.LayoutParams的相关属性
          * 具体用途请参考SDK文档
          */
         /*
          * 这个FIRST_SYSTEM_WINDOW的值就是2000。
          * 2003和2002的区别就在于2003类型的View比2002类型的还要top，
          * 能显示在系统下拉状态栏之上
          */
         wmParams.type=2002;   //这里是关键，你也可以试试2003
         wmParams.format=1;
          /**
          *这里的flags也很关键
          *代码实际是wmParams.flags |= FLAG_NOT_FOCUSABLE;
          *40的由来是wmParams的默认属性（32）+ FLAG_NOT_FOCUSABLE（8）
          */
         wmParams.flags=40;
         wmParams.width=100;
         wmParams.height=60;
         wm.addView(bb, wmParams);  //创建View
    }
}