如何控制Android中默认报警对话框的宽度和高度?

AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Title");
        builder.setItems(items, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int item) {
                Toast.makeText(getApplicationContext(), items[item], Toast.LENGTH_SHORT).show();
            }
        });
        AlertDialog alert = builder.create();
AlertDialog.Builder builder = new AlertDialog.B