popupwindow-彈出對話框

原文地址：http://code.eoe.cn/169
上方網址有demo檔案

/***
 * PopupWindow
 * 
 * @author zhangjia
 * 
 */
public class MainActivity extends Activity {
 private Button button;
 private PopupWindow popupWindow;
 private LinearLayout layout;
 private ListView listView;
 private String title[] = { "全部", "我的微博", "周边", "智能排版", "同学" };

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  requestWindowFeature(Window.FEATURE_NO_TITLE);
  setContentView(R.layout.main);
  button = (Button) findViewById(R.id.tv_title);
  button.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View v) {
    button.getTop();
    int y = button.getBottom() * 3 / 2;
    int x = getWindowManager().getDefaultDisplay().getWidth() / 4;

    showPopupWindow(x, y);
   }
  });
 }

 public void showPopupWindow(int x, int y) {
  layout = (LinearLayout) LayoutInflater.from(MainActivity.this).inflate(
    R.layout.dialog, null);
  listView = (ListView) layout.findViewById(R.id.lv_dialog);
  listView.setAdapter(new ArrayAdapter<String>(MainActivity.this,
    R.layout.text, R.id.tv_text, title));

  popupWindow = new PopupWindow(MainActivity.this);
  popupWindow.setBackgroundDrawable(new BitmapDrawable());
  popupWindow
    .setWidth(getWindowManager().getDefaultDisplay().getWidth() / 2);
  popupWindow.setHeight(300);
  popupWindow.setOutsideTouchable(true);
  popupWindow.setFocusable(true);
  popupWindow.setContentView(layout);
  // showAsDropDown会把里面的view作为参照物，所以要那满屏幕parent
  // popupWindow.showAsDropDown(findViewById(R.id.tv_title), x, 10);
  popupWindow.showAtLocation(findViewById(R.id.main), Gravity.LEFT
    | Gravity.TOP, x, y);//需要指定Gravity，默认情况是center.

  listView.setOnItemClickListener(new OnItemClickListener() {

   @Override
   public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
     long arg3) {
    button.setText(title[arg2]);
    popupWindow.dismiss();
    popupWindow = null;
   }
  });
 }

}