PopupWindow在Android.widget包下，项目中经常会使用到PopupWindow做菜单选项， PopupWindow这个类用来实现一个弹出框，可以使用任意布局的View作为其内容，这个弹出框是悬浮在当前activity之上的。
效果图：
MainActivity.java
1 public class MainActivity extends Activityimplements OnClickListener { 2 3 private PopupWindowm PopWindow; 4 private View parentView; 5 private Context context; 6 ImageView mImageViewBar; 7 8 @Override 9 protected void onCreate(Bundle savedInstanceState) { 10 super.onCreate(savedInstanceState); 11 requestWindowFeature(Window.FEATURE_NO_TITLE); 12 setContentView(R.layout.activity_main); 13 context = this; 14 initView(); 15 } 16 17 private void initView() { 18 // TODOAuto-generated method stub 19 parentView =getLayoutInflater().inflate(R.layout.activity_main,null); 20 mImageViewBar =(ImageView) findViewById(R.id.menu); 21 mImageViewBar.setOnClickListener(this); 22 showPopupWindow(); 23 } 24 25 private void showPopupWindow() { 26 LayoutInflater inflater = (LayoutInflater)context 27 .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 28 View contentView =inflater.inflate(R.layout.popuplayout,null); 29 mPopWindow = newPopupWindow(contentView); 30 mPopWindow.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT); 31 mPopWindow.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT); 32 mPopWindow = newPopupWindow(); 33 // 设置SelectPicPopupWindow的View 34 mPopWindow.setContentView(contentView); 35 // 设置SelectPicPopupWindow弹出窗体的宽 36 mPopWindow.setWidth(LayoutParams.WRAP_CONTENT); 37 // 设置SelectPicPopupWindow弹出窗体的高 38 mPopWindow.setHeight(LayoutParams.WRAP_CONTENT); 39 // 设置SelectPicPopupWindow弹出窗体可点击 40 mPopWindow.setFocusable(true); 41 mPopWindow.setOutsideTouchable(true); 42 // 刷新状态 43 mPopWindow.update(); 44 // 实例化一个ColorDrawable颜色为半透明 45 ColorDrawable dw = new ColorDrawable(0000000000); 46 // 点back键和其他地方使其消失,设置了这个才能触发OnDismisslistener，设置其他控件变化等操作 47 mPopWindow.setBackgroundDrawable(dw); 48 contentView.findViewById(R.id.memu1).setOnClickListener(this); 49 contentView.findViewById(R.id.memu2).setOnClickListener(this); 50 contentView.findViewById(R.id.memu3).setOnClickListener(this); 51 } 52 53 @Override 54 public void onClick(View v) { 55 int id =v.getId(); 56 switch (id) { 57 case R.id.menu: 58 mPopWindow.showAsDropDown(mImageViewBar); 59 break; 60 case R.id.memu1: { 61 Toast.makeText(context,"消息", Toast.LENGTH_SHORT).show(); 62 mPopWindow.dismiss(); 63 } 64 break; 65 case R.id.memu2: { 66 Toast.makeText(context,"收藏", Toast.LENGTH_SHORT).show(); 67 mPopWindow.dismiss(); 68 } 69 break; 70 case R.id.memu3: { 71 Toast.makeText(context,"首页", Toast.LENGTH_SHORT).show(); 72 mPopWindow.dismiss(); 73 } 74 break; 75 } 76 } 77 78 @Override 79 protected void onDestroy() { 80 // TODOAuto-generated method stub 81 super.onDestroy(); 82 mPopWindow.dismiss(); 83 } 84 }