接上篇代码

package com.view;


import android.app.Activity;
import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;

public class MainActivity extends Activity {

    private android.widget.PopupWindow popWindow;
    
    private Button btn = null;
    private View v;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main2);
        v = new View(this.getApplicationContext());
        v.setBackgroundColor(Color.RED);
        
        btn = (Button)findViewById(R.id.Button01);
        
        popWindow = new android.widget.PopupWindow(v,   
                LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
        asycTask.execute();
        
         
    }

    private AsyncTask asycTask = new AsyncTask() {

        @Override
        protected Object doInBackground(Object... params) {
            // TODO Auto-generated method stub
            return null;
        }
        @Override
        protected void onPostExecute(java.lang.Object result) {
            showPopupWindowHandler.sendEmptyMessage(1);
        }
    };
    
    private Handler showPopupWindowHandler = new Handler(){
        @Override
        public void handleMessage(android.os.Message msg) {
            if(msg.what == 1) {
                popWindow.showAtLocation(btn, android.view.Gravity.CENTER, 0, 0);
            }
        }
        
    };
    
}