android dialog点击确定dialog不消失

try {
java.lang.reflect.Field field = alertDialog.getClass().getSuperclass().getDeclaredField("mShowing");
field.setAccessible(true);
field.set(alertDialog, false);
} catch (Exception e) {
e.printStackTrace();
}

setNegativeButton("取消", new DialogInterface.OnClickListener() {
				
				@Override
				public void onClick(DialogInterface arg0, int arg1) {
					try {
						java.lang.reflect.Field field = alertDialog.getClass().getSuperclass().getDeclaredField("mShowing");
						field.setAccessible(true);
						field.set(alertDialog, true);
						} catch (Exception e) {
						e.printStackTrace();
						}
				}
			})