c# - 使用 caliburn micro 和 fluent Validation 通过按钮进行验证

Question

我想使用 caliburn micro 和 FluentValidation 显示对按钮事件的验证。验证规则当前按预期显示，但在单击按钮之前我无法隐藏它们。Wpf 相当新，所以请放轻松。我试图绑定 ValidatesOnDataErrors 但无法绑定。此外，我试图隐藏显示错误的 ControlTemplate

我的观点

<UserControl.Resources>
    <BooleanToVisibilityConverter x:Key="booleanVisibilityConverter"/>
</UserControl.Resources>

<Canvas FocusManager.FocusedElement="{Binding ElementName=box}">
    <!-- Sets the focus to start with textbox-->
    <Button x:Name="ValidateText" Content="Validate" Canvas.Left="234" Canvas.Top="265" Width="301" Height="29" />

    <TextBox  Height="23" Canvas.Left="205" TextWrapping="Wrap" Text="{Binding Name, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" 
              Canvas.Top="187" Width="330" TabIndex="0" x:Name="box" >
        <Validation.ErrorTemplate >
            <ControlTemplate >
                <StackPanel Orientation="Horizontal" >
                    <!-- Placeholder for the TextBox itself -->
                    <AdornedElementPlaceholder x:Name="textBox" />
                    <TextBlock Margin="10" Text="{Binding [0].ErrorContent}" Foreground="Red"  />
                </StackPanel>
            </ControlTemplate>
        </Validation.ErrorTemplate>
    </TextBox>
</Canvas>

验证：

 public class UserValidator : AbstractValidator<TestViewModel>
    {
        public UserValidator()
        {
            RuleFor(x => x.Name)
                .NotEmpty()
                .WithMessage("No name entered");
        }
    }

视图模型：

    public class TestViewModel : Screen, IDataErrorInfo

    {
        public bool Hello { get; set; } = false;

        private readonly UserValidator _userValidator;
        private bool _showHideError = false;

        public bool ShowHideError
        {
            get { return _showHideError; }
            set { _showHideError = value;
                NotifyOfPropertyChange(() => ShowHideError);
            }
        }

        public TestViewModel()
        {
            _userValidator = new UserValidator();
        }

        public string Name { get; set; }
        private string _lastName;

        public string LastName
        {
            get { return _lastName; }
            set
            {
                _lastName = value;
                NotifyOfPropertyChange(() => LastName);
            }
        }

        public string this[string columnName]
        {
            get
            {
                var firstOrDefault = _userValidator.Validate(this).Errors.FirstOrDefault(lol => lol.PropertyName == columnName);
                if (firstOrDefault != null)
                    return _userValidator != null ? firstOrDefault.ErrorMessage : "";
                return "";
            }
        }
        public string Error
        {
            get
            {
                if (_userValidator != null)
                {
                    FluentValidation.Results.ValidationResult results = _userValidator.Validate(this);
                    if (results != null && results.Errors.Any())
                    {
                        string errors = string.Join(Environment.NewLine, results.Errors.Select(x => x.ErrorMessage).ToArray());
                        return errors;
                    }
                }
                return string.Empty;
            }
        }
        public void ValidateText()
        {
            //Display Error on View when this is fired
        }
    }
}

标签： c#wpfcaliburn.microfluentvalidation

Answer 1

弄清楚了！我创建了一个名为 Validation 的标志，并在 HomepageViewModel 加载时将其设置为 false。然后我在以下代码中检查验证是否为真：

    public string this[string columnName]
    {
        get
        {
            if (!Validation)
            {
                return null;
            }
            var firstOrDefault = _userValidator.Validate(this).Errors.FirstOrDefault(lol => lol.PropertyName == columnName);
            if (firstOrDefault != null)
                return _userValidator != null ? firstOrDefault.ErrorMessage : "";
            return "";
        }
    }
    public string Error
    {
        get
        {
            if (Validation)
            {

                if (_userValidator != null)
                {
                    FluentValidation.Results.ValidationResult results = _userValidator.Validate(this);
                    if (results != null && results.Errors.Any())
                    {
                        string errors = string.Join(Environment.NewLine, results.Errors.Select(x => x.ErrorMessage).ToArray());
                        return errors;
                    }
                } 
            }
            return string.Empty;
        }

当调用按钮方法时，我将 flag(validation) 设置为 true，并且 notify 属性更改为更新视图，如下所示：

        Validation = true; // turn on validation
        NotifyOfPropertyChange(null); //refresh the properties/view

工作示例位于： https ://github.com/zenloki/TestButtonValidation

希望这对将来的人有所帮助