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：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/main"
    android:orientation="horizontal"
    >
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btn_show"
        android:text="show" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btn_close"
        android:text="close"/>

</LinearLayout>

music_popwindow.xml：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:background="#77777777"

android:orientation="vertical" >

<Button android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="right"

android:text="like"/>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#77777777"
    android:orientation="vertical" >
    <Button android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:text="like"/>

</LinearLayout>