1 1）更改AlertDialog窗口大小的方法：
 2 AlertDialog dialog = new AlertDialog.Builder(this).create();
 3 dialog.show();
 4 WindowManager.LayoutParams params = dialog.getWindow().getAttributes();
 5 params.width = 200;
 6 params.height = 200 ;
 7 dialog.getWindow().setAttributes(params);
 8 
 9 2）去除边框
10 AlertDialog.setView(view,0,0,0,0);