Windows Manager中的视图始终为null

Question

我有一个BroadcastReceiver用于来电和接听来电我想要给视图充气。

但是当我在调用状态为IDLE时尝试删除视图时，应用程序崩溃： java.lang.IllegalArgumentException：view不能为null

我的代码：

showview();

在onPostExecute中我调用

public void showview(){

    params = new WindowManager.LayoutParams(WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT,
            WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY, WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
            | WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE, PixelFormat.TRANSLUCENT);

    params.gravity = Gravity.CENTER | Gravity.CENTER;
    params.flags |= WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;

    wm = (WindowManager) mContext.getSystemService(mContext.WINDOW_SERVICE);

    inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    view = inflater.inflate(R.layout.child, null);
    txtIncomingnumber = (TextView) view.findViewById(R.id.txtviewoncall);
    txtIncomingnumber.setText("TEST");
    wm.addView(view, params);

}

public void removeview(){


        wm.removeView(view);


}

这是我的方法：

 .gallery-item {
     display: none;
  }