切换键盘

使用了自定义键盘之后需要切换回系统自带的数字键盘

- (void)changeKeyBoard{

    [_inputView becomeFirstResponder];

    _inputView.inputView = nil;

    [_inputView reloadInputViews];

  _inputView.keyboardType = UIKeyboardTypeNumbersAndPunctuation;

}