Android高手之路之popUpWindow的显示与关闭

popWIndow的效果就类似一个固定的小窗口。直接看效果吧

效果：

主要代码：

package com.example.popupwindowdemo;

import android.os.Bundle;
import android.app.Activity;
import android.app.ActionBar.LayoutParams;
import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.PopupWindow;

public class MainActivity extends Activity implements OnClickListener{
	private Button btn_show,btn_close;
	private PopupWindow mPopupWindow;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		btn_show = (Button)findViewById(R.id.btn_show);
		btn_show.setOnClickListener(this);
		
		btn_close = (Button)findViewById(R.id.btn_close);
		btn_close.setOnClickListener(this);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

	@Override
	public void onClick(View v) {
		switch (v.getId()) {
		case  R.id.btn_show:
			if(null == mPopupWindow || !mPopupWindow.isShowing()){
				LayoutInflater mLayoutInflater = (LayoutInflater) this  
			            .getSystemService(LAYOUT_INFLATER_SERVICE);
				 View music_popunwindwow = mLayoutInflater.inflate(  
				            R.layout.music_popwindow, null); 
				 mPopupWindow = new PopupWindow(music_popunwindwow,LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT);
				 mPopupWindow.showAtLocation(findViewById(R.id.main), Gravity.RIGHT|Gravity.BOTTOM, 0, 0);
			}
			
			break;
		case R.id.btn_close:
			if(null != mPopupWindow && mPopupWindow.isShowing()){
				mPopupWindow.dismiss();
				if(null == mPopupWindow){
					Log.e("MainActivity","null == mPopupWindow");
				}
			}
			break;
		default:
			break;
		}
	
		
	}
	
	

}

activity_main.xml：

music_popwindow.xml：