PopupWindow的使用
在做Menu菜单时，系统为我们提供的Menu菜单在实际开发时，并不能满足我们的要求，于是想起来了PopupWindow，SDK API是对样对PopupWindow定义的：A popup window that can be used to display an arbitrary view. The popup windows is a floating container that appears on top of the current activity.? 大概意思是这样：这是一个可以显示任意的View的弹出窗口，这个窗口是浮动在当前的Activity上的，
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下面就用一个小例子来展示下PopupWindow的用法吧！下面就用一个Menu菜单作为例子,我个人比较喜欢用XML文件，所以下面都以XML为主
首先来写Menu菜单的布局 menu_item.xml：
?它的样式只是显示一排，这一拓为四个按钮，为了让例子更加清楚，我把其它的代码都删了
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Main.xml：
?这里的布局不会影响到具体的操作，所以我也没有怎么改。
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下面的代码才是关键
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package com.hilary.dialog;import android.app.Activity;import android.os.Bundle;import android.view.Gravity;import android.view.KeyEvent;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.GridView;import android.widget.LinearLayout;import android.widget.PopupWindow;import com.hilary.R;public class PopupWindowActivity extends Activity {public static PopupWindow popupWindow;private LinearLayout linear1_1;private LinearLayout linear1_2;private LinearLayout linear1_3;private LinearLayout linear1_4;View menuView = null;View parent = null;GridView gridView;LinearLayout linear;/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.popup_window);initWeight();initListener();}private void initWeight() {menuView = PopupWindowActivity.this.getLayoutInflater().inflate(R.layout.menu_list, null);parent = getLayoutInflater().inflate(R.layout.popup_window, null);popupWindow = new PopupWindow(menuView, LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT, false);/* * 设置此项为true时，会让其这个popupWindow处于焦点，其它控件(除主页面键)都会 * 失去焦点，不可点击 * popupWindow.setFocusable(true); *//* * 有的人说让下面这两项设计结合可以让PopupWindow失去焦点从而实现点击别的控件时， * PopupWindow会消失,这样虽然是可以实现这样的效果，但有一点不足之处就是，这样他 * 会重构你点击那项的背景，当你与点击selector并用时，就是产生你点击那项，它的内 * 容会消失(在你重写按钮背景时)，也许是因为那项的背景重构的事吧。。所以大家千万不要这样做 * * popupWindow.setOutsideTouchable(true); * popupWindow.setBackgroundDrawable(new BitmapDrawable()); * */popupWindow.setAnimationStyle(R.style.MenuAnimation);/*gridView = (GridView) findViewById(R.id.gridView);linear1_1 = (LinearLayout) menuView.findViewById(R.id.item1_1);linear1_2 = (LinearLayout) menuView.findViewById(R.id.item1_2);linear1_3 = (LinearLayout) menuView.findViewById(R.id.item1_3);linear1_4 = (LinearLayout) menuView.findViewById(R.id.item1_4);}private void initListener() {linear1_1.setOnClickListener(new ClickEvent());linear1_2.setOnClickListener(new ClickEvent());linear1_3.setOnClickListener(new ClickEvent());linear1_4.setOnClickListener(new ClickEvent());gridView.setOnTouchListener(new OnTouchListener() {@Overridepublic boolean onTouch(View v, MotionEvent event) {if(popupWindow != null && popupWindow.isShowing()){_setDismiss();}return false;}});}public void getPopupWindow() {if (popupWindow == null) {_showingPopupWindw();} else {if (popupWindow.isShowing()) {_setDismiss();} else {_showingPopupWindw();}}}@Overridepublic boolean onKeyUp(int keyCode, KeyEvent event) {if (keyCode == KeyEvent.KEYCODE_MENU) {if (popupWindow != null) {if (popupWindow.isShowing()) {_setDismiss();} else {getPopupWindow();}} else {getPopupWindow();}} else if (keyCode == KeyEvent.KEYCODE_BACK) {if(popupWindow != null && popupWindow.isShowing()){_setDismiss();}else{System.exit(0);}}return false;}@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {System.out.println("onKeyDown");return false;}private class ClickEvent implements OnClickListener {@Overridepublic void onClick(View v) {switch (v.getId()) {case R.id.btn1:getPopupWindow();break;case R.id.btn2:getPopupWindow();break;case R.id.item1_1:System.out.println("item1_1");break;case R.id.item1_2:System.out.println("item1_2");break;case R.id.item1_3:System.out.println("item1_3");break;case R.id.item1_4:System.out.println("item1_4");break;}popupWindow.dismiss();}}public void _setDismiss() { popupWindow.dismiss();}public void _showingPopupWindw(){popupWindow.showAtLocation(parent, Gravity.BOTTOM, 0, 0);}}?在我们用PopupWindow时，都会与某种布局结合应用，如我上面的应用，UC上的应用是与WebView应用，所以在点击外面时，PopupWindow消失，要在WebView上添加Touch监听事件，如果在整个布局上添加Touch是不成效的
