<?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="#FFBBFFBB"
  android:orientation="vertical" >

  <TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="10dp"
    android:text="Hello My Window"
    android:textSize="20sp" />

  <Button
    android:id="@+id/button1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="10dp"
    android:text="Button"
    android:textSize="20sp" />

</LinearLayout>

package com.example.hellopopupwindow;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.PopupWindow;
import android.widget.Toast;

public class MainActivity extends Activity {

  private Context mContext = null;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mContext = this;

    Button button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {

      @Override
      public void onClick(View view) {

        showPopupWindow(view);
      }
    });
  }

  private void showPopupWindow(View view) {

    // 一个自定义的布局，作为显示的内容
    View contentView = LayoutInflater.from(mContext).inflate(
        R.layout.pop_window, null);
    // 设置按钮的点击事件
    Button button = (Button) contentView.findViewById(R.id.button1);
    button.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        Toast.makeText(mContext, "button is pressed",
            Toast.LENGTH_SHORT).show();
      }
    });

    final PopupWindow popupWindow = new PopupWindow(contentView,
        LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, true);

    popupWindow.setTouchable(true);

    popupWindow.setTouchInterceptor(new OnTouchListener() {

      @Override
      public boolean onTouch(View v, MotionEvent event) {

        Log.i("mengdd", "onTouch : ");

        return false;
        // 这里如果返回true的话，touch事件将被拦截
        // 拦截后 PopupWindow的onTouchEvent不被调用，这样点击外部区域无法dismiss
      }
    });

    // 如果不设置PopupWindow的背景，无论是点击外部区域还是Back键都无法dismiss弹框
    // 我觉得这里是API的一个bug
    popupWindow.setBackgroundDrawable(getResources().getDrawable(
        R.drawable.selectmenu_bg_downward));

    // 设置好参数之后再show
    popupWindow.showAsDropDown(view);

  }

}

public void showAtLocation(View parent, int gravity, int x, int y)

public void showAtLocation(IBinder token, int gravity, int x, int y) 

public void showAsDropDown(View anchor)

public void showAsDropDown(View anchor, int xoff, int yoff)

public void showAsDropDown(View anchor, int xoff, int yoff, int gravity) 

  /**
   * <p>Prepare the popup by embedding in into a new ViewGroup if the
   * background drawable is not null. If embedding is required, the layout
   * parameters' height is mnodified to take into account the background's
   * padding.</p>
   *
   * @param p the layout parameters of the popup's content view
   */
  private void preparePopup(WindowManager.LayoutParams p) {
    if (mContentView == null || mContext == null || mWindowManager == null) {
      throw new IllegalStateException("You must specify a valid content view by "
          + "calling setContentView() before attempting to show the popup.");
    }

    if (mBackground != null) {
      final ViewGroup.LayoutParams layoutParams = mContentView.getLayoutParams();
      int height = ViewGroup.LayoutParams.MATCH_PARENT;
      if (layoutParams != null &&
          layoutParams.height == ViewGroup.LayoutParams.WRAP_CONTENT) {
        height = ViewGroup.LayoutParams.WRAP_CONTENT;
      }

      // when a background is available, we embed the content view
      // within another view that owns the background drawable
      PopupViewContainer popupViewContainer = new PopupViewContainer(mContext);
      PopupViewContainer.LayoutParams listParams = new PopupViewContainer.LayoutParams(
          ViewGroup.LayoutParams.MATCH_PARENT, height
      );
      popupViewContainer.setBackgroundDrawable(mBackground);
      popupViewContainer.addView(mContentView, listParams);

      mPopupView = popupViewContainer;
    } else {
      mPopupView = mContentView;
    }
    mPopupViewInitialLayoutDirectionInherited =
        (mPopupView.getRawLayoutDirection() == View.LAYOUT_DIRECTION_INHERIT);
    mPopupWidth = p.width;
    mPopupHeight = p.height;
  }

 @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
      if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
        if (getKeyDispatcherState() == null) {
          return super.dispatchKeyEvent(event);
        }

        if (event.getAction() == KeyEvent.ACTION_DOWN
            && event.getRepeatCount() == 0) {
          KeyEvent.DispatcherState state = getKeyDispatcherState();
          if (state != null) {
            state.startTracking(event, this);
          }
          return true;
        } else if (event.getAction() == KeyEvent.ACTION_UP) {
          KeyEvent.DispatcherState state = getKeyDispatcherState();
          if (state != null && state.isTracking(event) && !event.isCanceled()) {
            dismiss();
            return true;
          }
        }
        return super.dispatchKeyEvent(event);
      } else {
        return super.dispatchKeyEvent(event);
      }
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
      if (mTouchInterceptor != null && mTouchInterceptor.onTouch(this, ev)) {
        return true;
      }
      return super.dispatchTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
      final int x = (int) event.getX();
      final int y = (int) event.getY();
      
      if ((event.getAction() == MotionEvent.ACTION_DOWN)
          && ((x < 0) || (x >= getWidth()) || (y < 0) || (y >= getHeight()))) {
        dismiss();
        return true;
      } else if (event.getAction() == MotionEvent.ACTION_OUTSIDE) {
        dismiss();
        return true;
      } else {
        return super.onTouchEvent(event);
      }
    }

 　　/**
   * Set whether this window is touch modal or if outside touches will be sent
   * to
   * other windows behind it.
   *
   */
  public static void setPopupWindowTouchModal(PopupWindow popupWindow,
      boolean touchModal) {
    if (null == popupWindow) {
      return;
    }
    Method method;
    try {

      method = PopupWindow.class.getDeclaredMethod("setTouchModal",
          boolean.class);
      method.setAccessible(true);
      method.invoke(popupWindow, touchModal);

    }
    catch (Exception e) {
      e.printStackTrace();
    }

  }