1

我有一个项目控件的模板：

<DataTemplate DataType="{x:Type models:StringParameter}">
         <TextBox materialDesign:HintAssist.Hint="{Binding Name}">
             <TextBox.Text>
                 <Binding Path="Value">
                     <Binding.ValidationRules>
                         <ınteractiveCode:NotEmptyValidationRule ValidatesOnTargetUpdated="True"></ınteractiveCode:NotEmptyValidationRule>
                     </Binding.ValidationRules>
                 </Binding>
             </TextBox.Text>
         </TextBox>
     </DataTemplate>

而且我有一个与命令一起使用的按钮，我希望在 ItemsControl 中满足所有验证时启用它。但是我找不到访问数据模板内的文本框的方法。

4

1 回答 1

1

我有一个简单的方法来解决这个特定问题。我创建了一个ValidationChecker类，它将使用方法检查是否存在验证错误IsValid。

public class ValidationChecker : Freezable
{
    public static List<DependencyObject> elements = new List<DependencyObject>();

    public static int GetValidationObject(DependencyObject obj)
    {
        return (int)obj.GetValue(ValidationObjectProperty);
    }

    public static void SetValidationObject(DependencyObject obj, int value)
    {
        obj.SetValue(ValidationObjectProperty, value);
    }

    // Using a DependencyProperty as the backing store for ErrorCount.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty ValidationObjectProperty =
        DependencyProperty.RegisterAttached("ValidationObject", typeof(DependencyObject), typeof(ValidationChecker), new PropertyMetadata(null, OnValueChanged));


    public static bool IsValid()
    {
        foreach (var item in elements)
        {
            if (Validation.GetHasError(item)) return false;
        }
        return true;
    }

    private static void OnValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        elements.Add(d);
    }

    protected override Freezable CreateInstanceCore()
    {
        return new ValidationChecker();
    }
}

ValidationObject附加属性可以如下实现

<DataTemplate>
    <TextBox local:ValidationChecker.ValidationObject="{Binding RelativeSource={RelativeSource Self}}">
         <TextBox.Text>
             <Binding Path="Value">
                 <Binding.ValidationRules>
                      <local:NotEmptyValidationRule ValidatesOnTargetUpdated="True"></local:NotEmptyValidationRule>
                 </Binding.ValidationRules>
              </Binding>
          </TextBox.Text>
       </TextBox>
</DataTemplate>

您已经提到您的Button已绑定到Command. 所以实现and callCanExecute的方法。不要忘记在需要时为此调用方法。CommandValidationChecker.Isvalid()RaiseCanExecuteCommand

于 2017-10-22T19:03:55.030 回答