使用IDataErrorInfo和ValidationRule组合显示DataGridCell的多个验证规则异常

Question

我有一个ValidationRule，我想将其用于验证DataGrid中的用户输入。 可能是因为用户输入的数据违反了一个以上的规则，因此可以在IDataErrorInfo实现类中检测到某些规则破坏者，而在ValidationRule类中可以检测到某些破坏者。因此，我想针对特定单元格将所有这些错误消息组合并显示给用户（也许使用工具提示） 。

例如，我要检查是否为';'包含在任何单元格中。我想在ValidationRule类中进行检查。
特定于某个单元的检查应在IDataErrorInfo实现模型类中完成。

我该如何实现？

我的IDataErrorInfo实现类：

public class RawTag : IDataErrorInfo, INotifyPropertyChanged
{
    private int hash;
    private string tagName;
    private string cycle;
    private string source;

    public RawTag()
    {
        RefreshHash();
    }

    public void RefreshHash()
    {
        hash = GetHashCode();
    }

    public RawTag(string tagName, string cycle, string source)
    {
        TagName = tagName;
        Cycle = cycle;
        Source = source;
        RefreshHash();
    }

    public string TagName
    {
        get => tagName;
        set
        {
            if (value == tagName) return;
            tagName = value;
            OnPropertyChanged();
        }
    }

    // should be an integer but any entered value shall be accepted
    public string Cycle
    {
        get => cycle;
        set
        {
            if (value == cycle)
            {
                return;
            }
            cycle = value;
            OnPropertyChanged();
        }
    }
    public string Source
    {
        get => source;
        set
        {
            if (value == source) return;
            source = value;
            OnPropertyChanged();
        }
    }

    string IDataErrorInfo.Error
    {
        get
        {
            StringBuilder error = new StringBuilder();
            if (string.IsNullOrEmpty(TagName))
            {
                error.Append("Name cannot be null or empty");
            }
            if (!int.TryParse(Cycle.ToString(), out int i))
            {
                error.Append("Cycle should be an integer value.");
            }

            return error.ToString();
        }
    }

    private void checkIfEmptyfieldsExists()
    {
        PropertyInfo[] properties = this.GetType().GetProperties();
    }

    private bool checkForInvalidCharacter(string value, string character)
    {
        return value.Contains(character);
    }

    string IDataErrorInfo.this[string columnName]
    {
        get
        {
            // apply property level validation rules
            if (columnName == "TagName")
            {
                if (string.IsNullOrEmpty(TagName))
                    return "Name cannot be null or empty";
            }

            if (columnName == "Cycle")
            {
                if (!int.TryParse(Cycle.ToString(), out int i))
                    return "Cycle should be an integer value.";
            }

            if (columnName == "Source")
            {
                if (string.IsNullOrEmpty(Source))
                    return "Source must not be empty";
            }

            return "";
        }
    }

    public override string ToString()
    {
        return "TagName: " + TagName + " Cycle: " + Cycle + " Source: " + Source;
    }

    public bool IsDirty()
    {
        return hash != GetHashCode();
    }

    protected bool Equals(RawTag other)
    {
        return string.Equals(TagName, other.TagName) && string.Equals(Cycle, other.Cycle) && string.Equals(Source, other.Source);
    }

    public override bool Equals(object obj)
    {
        if (ReferenceEquals(null, obj)) return false;
        if (ReferenceEquals(this, obj)) return true;
        if (obj.GetType() != this.GetType()) return false;
        return Equals((RawTag)obj);
    }

    public override int GetHashCode()
    {
        unchecked
        {
            var hashCode = (TagName != null ? TagName.GetHashCode() : 0);
            hashCode = (hashCode * 397) ^ (Cycle != null ? Cycle.GetHashCode() : 0);
            hashCode = (hashCode * 397) ^ (Source != null ? Source.GetHashCode() : 0);
            return hashCode;
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    [NotifyPropertyChangedInvocator]
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

我的ValidationRule类：

public class MyValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value,
        System.Globalization.CultureInfo cultureInfo)
    {
        BindingGroup group = (BindingGroup)value;
        StringBuilder error = null;
        foreach (var item in group.Items)
        {
            IDataErrorInfo info = item as IDataErrorInfo;
            if (info != null)
            {
                if (!string.IsNullOrEmpty(info.Error))
                {
                    if (error == null)
                    {
                        error = new StringBuilder();
                    }

                    Type type = item.GetType();
                    PropertyInfo[] properties = type.GetProperties();
                    foreach (PropertyInfo property in properties)
                    {
                        Console.WriteLine(property.GetValue(property.Name, null));
                        if (property.GetValue(property.Name, null).ToString().Contains(";"))
                        {
                            error.Append((error.Length != 0 ? ", " : "") + property.Name + " may not contain a ';'.");
                        }
                    }

                    error.Append((error.Length != 0 ? ", " : "") + info.Error);
                }
            }
        }

        if (error != null)
            return new ValidationResult(false, error.ToString());
        else
            return new ValidationResult(true, "");

    }
}

通过这种方式，LOC在CycleValidationRule中：if (error != null) return new ValidationResult(false, error.ToString()); 显示所有收集到的错误消息，但是当悬停单元格时，在DataGrid的最终工具提示中只有

  

“周期应为整数值。”

似乎已定义样式：

<Style x:Key="textBlockErrStyle" TargetType="{x:Type TextBlock}">
    <Style.Triggers>
        <DataTrigger Binding="{Binding Path=(Validation.HasError), RelativeSource={RelativeSource AncestorType=DataGridRow}}" Value="true" >
            <Setter Property="Background" Value="Red" />
            <Setter Property="Foreground" Value="White" />
            <Setter Property="ToolTip" Value="{Binding RelativeSource={x:Static RelativeSource.Self}, Path=(Validation.Errors)[0].ErrorContent}"/>
        </DataTrigger>
    </Style.Triggers>
</Style>

绑定到IDataErrorInfo，但没有绑定到我的CycleValiadtionRule验证错误。