PopupWindow罩层实现

例子:



PopupWindowActivity.java

package com.popup;

import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout.LayoutParams;
import android.widget.PopupWindow;

public class PopupwindowActivity extends Activity {
	public PopupWindow mPopupWindow;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		View popupWindow_view = getLayoutInflater().inflate(R.layout.control, null,false);
		mPopupWindow = new PopupWindow(popupWindow_view, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT,true);
		Button show = (Button) findViewById(R.id.button1);
		show.setOnClickListener(new Button.OnClickListener() {
			@Override
			public void onClick(View v) {
				mPopupWindow.showAtLocation(findViewById(R.id.linear),Gravity.RIGHT | Gravity.BOTTOM, 0, 0);
			}
		});
		mPopupWindow.update();
		 //获取自定义布局文件popup.xml的视图
		Button btn1 = (Button)popupWindow_view.findViewById(R.id.button2);
		btn1.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				mPopupWindow.dismiss();
			}
		});
	}
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"  android:id="@+id/linear">
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button" />

</LinearLayout>

control.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:background="#b0000000"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical|center_horizontal"
        android:text="Button" />

</LinearLayout>