android 弹出式textview,android-PopupWindow中的自动完成TextView

我在按钮单击上显示PopupWindow是这样的.

public void Search_Click(View view) {

try

{

Display display=getWindowManager().getDefaultDisplay();

LayoutInflater inflater = (LayoutInflater) IssueTokenActivity.this

.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

View layout = inflater.inflate(R.layout.activity_pop_up_transporter_details,

(ViewGroup) findViewById(R.id.popup_element));

AutoCompleteTextView act=(AutoCompleteTextView)layout.findViewById(R.id.act_trans_name);

ArrayAdapter dataadapter=new ArrayAdapter(view.getContext(), android.R.layout.simple_dropdown_item_1line,list);

dataadapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

act.setAdapter(dataadapter);

act.setThreshold(1);

//TODO: Need to support for higher API

pwindo = new PopupWindow(layout,display.getWidth()-60, display.getHeight()-400, true);

pwindo.showAtLocation(layout, Gravity.CENTER, 0, 0);

btnClosePopup = (Button) layout.findViewById(R.id.btn_close_popup);

btnClosePopup.setOnClickListener(cancel_button_click_listener);

}

catch (Exception e)

{

e.printStackTrace();

}

}

但是我在输入AutoCompleted TextView时遇到此错误.

06-20 09:15:47.091: E/AndroidRuntime(23277): android.view.WindowManager$BadTokenException: Unable to add window -- token android.view.ViewRootImpl$W@40ece840 is not valid; is your activity running?

06-20 09:15:47.091: E/AndroidRuntime(23277): at android.view.ViewRootImpl.setView(ViewRootImpl.java:567)

06-20 09:15:47.091: E/AndroidRuntime(23277): at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:246)

06-20 09:15:47.091: E/AndroidRuntime(23277): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)

06-20 09:15:47.091: E/AndroidRuntime(23277): at android.widget.PopupWindow.invokePopup(PopupWindow.java:993)

06-20 09:15:47.091: E/AndroidRuntime(23277): at android.widget.PopupWindow.showAsDropDown(PopupWindow.java:899)

06-20 09:15:47.091: E/AndroidRuntime(23277): at android.widget.ListPopupWindow.show(ListPopupWindow.java:603)