使用PopupWindow创建一个简单的菜单

PopupWindow是一个弹出式窗口，它可以展示任意View。他会浮在当前窗口的上方展示。

下面看代码：

public class MyActivity extends Activity { private PopupWindow menu; private LayoutInflater inflater; private View layout; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //实例化PopupWindow创建菜单 initMenu(); } //判断按键 菜单的显示与隐藏 @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if(!menu.isShowing()&&keyCode == KeyEvent.KEYCODE_MENU){ show(); }else{ menu.dismiss(); } if(keyCode == KeyEvent.KEYCODE_BACK&&menu.isShowing()){ menu.dismiss(); } return true; } //实例化PopupWindow创建菜单 private void initMenu(){ //获取LayoutInflater实例 inflater = (LayoutInflater) this.getSystemService(LAYOUT_INFLATER_SERVICE); //获取弹出菜单的布局 layout = inflater.inflate(R.layout.menu,null); //设置popupWindow的布局 menu = new PopupWindow(layout, WindowManager.LayoutParams.WRAP_CONTENT,WindowManager.LayoutParams.WRAP_CONTENT); } //显示菜单 private void show(){ //设置位置 menu.showAtLocation(this.findViewById(R.id.main), Gravity.BOTTOM|Gravity.CENTER_HORIZONTAL,0,0); //设置在屏幕中的显示位置 } }

菜单的布局文件：

<?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="horizontal" > <ImageView android:id="@+id/icon_1" android:background="@drawable/icon_1" android:layout_width="40dp" android:layout_height="40dp"/> <ImageView android:id="@+id/icon_2" android:background="@drawable/icon_2" android:layout_width="40dp" android:layout_height="40dp"/> <ImageView android:id="@+id/icon_3" android:background="@drawable/icon3" android:layout_width="40dp" android:layout_height="40dp"/> <ImageView android:id="@+id/icon_4" android:background="@drawable/icon4" android:layout_width="40dp" android:layout_height="40dp"/> </LinearLayout>