GridViewBase.InvalidRowException Event

Occurs when a row fails validation or cannot be saved to a data source.

Namespace: DevExpress.Xpf.Grid

Assembly: DevExpress.Xpf.Grid.v21.2.dll

Declaration

public event InvalidRowExceptionEventHandler InvalidRowException

Event Data

The InvalidRowException event's data class is InvalidRowExceptionEventArgs. The following properties provide information specific to this event:

Property Description
ErrorText Gets or sets the error description.
Exception Gets the exception that raised the GridViewBase.InvalidRowException event.
ExceptionMode Gets or sets a value that specifies how an exception should be handled.
Handled Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. Inherited from RoutedEventArgs.
OriginalSource Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs.
RoutedEvent Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. Inherited from RoutedEventArgs.
Row Gets the processed row. Inherited from RowEventArgs.
RowHandle Gets the processed row’s handle. Inherited from RowEventArgs.
Source Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs.
WindowCaption Gets or sets the error window’s caption.

The event data class exposes the following methods:

Method Description
InvokeEventHandler(Delegate, Object) When overridden in a derived class, provides a way to invoke event handlers in a type-specific way, which can increase efficiency over the base implementation. Inherited from RoutedEventArgs.
OnSetSource(Object) When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. Inherited from RoutedEventArgs.

Remarks

Use the GridViewBase.ValidateRow event to validate entered values. After this event is handled, the InvalidRowException event occurs and allows you to specify how to display validation errors.

Use the InvalidRowExceptionEventArgs.ExceptionMode property to specify which action to perform when a user enters an invalid value. You can display a message box with an error description, suppress an action, throw an exception, or ignore the validation result.

If you want to maintain a clean MVVM pattern and specify an error presentation in a View Model, create a command and bind it to the InvalidRowExceptionCommand property.

Refer to the following help topic for more information: Row Validation.

Example

This example shows how to check if a user enters valid data into a row. Handle the GridViewBase.ValidateRow and GridViewBase.InvalidRowException events to validate the focused row’s data. If the data is invalid, do not allow the user to move focus to another row until the invalid values are corrected.

The Task class implements the IDataErrorInfo interface and allows you to get error descriptions for the entire row and individual cells (data source fields). Error icons appear in cells that contain invalid values. Hover the mouse pointer over an error icon to display a tooltip with an error description.

DevExpress WPF | Grid Control - Validate Data Rows

View Example: How to Validate Data Rows

<dxg:GridControl x:Name="grid" AutoGenerateColumns="AddNew">
    <dxg:GridControl.View>
        <dxg:TableView AutoWidth="True"
                       ValidateRow="OnValidateRow"
                       InvalidRowException="OnInvalidRowException"/>
    </dxg:GridControl.View>
</dxg:GridControl>
public class Task : IDataErrorInfo {
    public string TaskName { get; set; }
    public DateTime StartDate { get; set; }
    public DateTime EndDate { get; set; }

    string IDataErrorInfo.Error => StartDate > EndDate ? "Either Start Date or End Date should be corrected." : null;
    string IDataErrorInfo.this[string columnName] {
        get {
            switch(columnName) {
                case nameof(StartDate):
                    if(StartDate > EndDate)
                        return "Start Date must be less than End Date";
                    break;
                case nameof(EndDate):
                    if(StartDate > EndDate)
                        return "End Date must be greater than Start Date";
                    break;
                case nameof(TaskName):
                    if(string.IsNullOrEmpty(TaskName))
                        return "Enter a task name";
                    break;
            }
            return null;
        }
    }
}
public partial class MainWindow : Window {
// ...
    void OnValidateRow(object sender, GridRowValidationEventArgs e) {
        var task = (Task)e.Row;
        if(task.StartDate > task.EndDate)
            e.SetError("Start Date must be less than End Date");
        if(string.IsNullOrEmpty(task.TaskName))
            e.SetError("Enter a task name");
    }

    void OnInvalidRowException(object sender, InvalidRowExceptionEventArgs e) {
        e.ExceptionMode = ExceptionMode.NoAction;
    }
}
See Also