安卓学习第36课——PopupWindow

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:gravity="center_horizontal"
    android:background="#B6A8D9">

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="240dp"
        android:src="@drawable/a" />

    <Button
        android:id="@+id/close"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="关闭" />

</LinearLayout>

<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:orientation="vertical"
    android:gravity="center_horizontal">

    <Button
        android:id="@+id/bn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="弹出Popup窗口" />

</LinearLayout>

package com.example.popupwindow;

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

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //装载R.Layout.popup对应的界面布局
        View root=this.getLayoutInflater().inflate(R.layout.popup, null);
        //创建PopupWindow对象
        final PopupWindow popup=new PopupWindow(root,280,280);
        Button button=(Button) findViewById(R.id.bn);
        button.setOnClickListener(new  OnClickListener(){
            @Override
            public void onClick(View v) {
                //下拉方式显示(按钮下方)
                popup.showAsDropDown(v);
                //设置指定位置
                //popup.showAtLocation(findViewById(R.id.bn), Gravity.CENTER, 20, 20);
            }

        });
        //获取PopupWindow中的关闭按钮
        root.findViewById(R.id.close).setOnClickListener(new OnClickListener(){

            @Override
            public void onClick(View v) {
                popup.dismiss();
            }

        });
    }

}