public boolean onKeyDown(int keyCode, KeyEvent event) {
 // 如果是返回鍵,直接返回到桌面
 if(keyCode == KeyEvent.KEYCODE_BACK || keyCode == KeyEvent.KEYCODE_HOME){
      showExitGameAlert();
 }
 return super.onKeyDown(keyCode, event);
}
private void showExitGameAlert() {
 final AlertDialog dlg = new AlertDialog.Builder(this).create();
 dlg.show();
 Window window = dlg.getWindow();
    // *** 主要就是在這里實現(xiàn)這種效果的.
    // 設置窗口的內(nèi)容頁面,shrew_exit_dialog.xml文件中定義view內(nèi)容
 window.setContentView(R.layout.shrew_exit_dialog);
    // 為確認按鈕添加事件,執(zhí)行退出應用操作
 ImageButton ok = (ImageButton) window.findViewById(R.id.btn_ok);
 ok.setOnClickListener(new View.OnClickListener() {
 public void onClick(View v) {
  exitApp(); // 退出應用...
 }
 });
    // 關閉alert對話框架
    ImageButton cancel = (ImageButton) window.findViewById(R.id.btn_cancel);
    cancel.setOnClickListener(new View.OnClickListener() {
  public void onClick(View v) {
  dlg.cancel();
 }
  });
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
 xmlns:Android="http://schemas.android.com/apk/res/android"
 android:layout_height="wrap_content"
 android:layout_width="wrap_content">
 <!-- 退出游戲的背景圖 -->
 <ImageView android:id="@+id/exitGameBackground"
 android:layout_centerInParent="true"
 android:layout_height="wrap_content"
 android:layout_width="wrap_content"
 android:src="@drawable/bg_exit_game" />
 <!-- 確認按鈕 -->
 <ImageButton android:layout_alignBottom="@+id/exitGameBackground"
 android:layout_alignLeft="@+id/exitGameBackground"
 android:layout_marginBottom="30dp"
 android:layout_marginLeft="35dp"
 android:id="@+id/btn_ok"
 android:layout_height="wrap_content"
 android:layout_width="wrap_content"
 android:background="@drawable/btn_ok" />
 <!-- 取消按鈕 -->
 <ImageButton android:layout_alignBottom="@+id/exitGameBackground"
 android:layout_alignRight="@+id/exitGameBackground"
 android:layout_marginBottom="30dp"
 android:layout_marginRight="35dp"
 android:id="@+id/btn_cancel"
 android:layout_height="wrap_content"
 android:layout_width="wrap_content"
 android:background="@drawable/btn_cancel" />
</RelativeLayout>