ValidationResult.ErrorContent Property

Gets an object that provides additional information about the invalidity.

Namespace:  System.Windows.Controls
Assembly:  PresentationFramework (in PresentationFramework.dll)

'Declaration
Public ReadOnly Property ErrorContent As Object

Property Value

Type: System.Object
An object that provides additional information about the invalidity.

The WPF data binding model enables you to associate ValidationRules with your Binding or MultiBinding object. You can create custom rules by subclassing the ValidationRule class and implementing the Validate method. The Validate method returns a ValidationResult object to report whether the checked value is valid.

For a detailed discussion of the validation process, see "Data Validation" in Data Binding Overview.

The following example shows the implementation of a validation rule that marks the input value as invalid if it contains non-numeric characters or outside the lower and upper bounds. If the value is invalid, the ErrorContent property and the IsValid property of the returned ValidationResult are set to the appropriate error message and false respectively.

For the complete example, see How to: Implement Binding Validation.

public class AgeRangeRule : ValidationRule
{
    private int _min;
    private int _max;

    public AgeRangeRule()
    {
    }

    public int Min
    {
        get { return _min; }
        set { _min = value; }
    }

    public int Max
    {
        get { return _max; }
        set { _max = value; }
    }

    public override ValidationResult Validate(object value, CultureInfo cultureInfo)
    {
        int age = 0;

        try
        {
            if (((string)value).Length > 0)
                age = Int32.Parse((String)value);
        }
        catch (Exception e)
        {
            return new ValidationResult(false, "Illegal characters or " + e.Message);
        }

        if ((age < Min) || (age > Max))
        {
            return new ValidationResult(false,
              "Please enter an age in the range: " + Min + " - " + Max + ".");
        }
        else
        {
            return new ValidationResult(true, null);
        }
    }
}

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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