Android 改变AlertDialog的大小

1）更改AlertDialog窗口大小的方法：
AlertDialog dialog = new AlertDialog.Builder(this).create();
dialog.show();
WindowManager.LayoutParams params = dialog.getWindow().getAttributes();
params.width = 200;
params.height = 200 ;
dialog.getWindow().setAttributes(params);

2）去除边框
AlertDialog.setView(view,0,0,0,0);