wpf-devexpress-dot-xpf-dot-grid-2f03e8fc.md
Populates the GridViewBase.ValidateRow event handler with data.
Namespace : DevExpress.Xpf.Grid
Assembly : DevExpress.Xpf.Grid.v25.2.Core.dll
NuGet Package : DevExpress.Wpf.Grid.Core
public class GridRowValidationEventArgs :
ValidationEventArgs,
IDataRowEventArgs
Public Class GridRowValidationEventArgs
Inherits ValidationEventArgs
Implements IDataRowEventArgs
GridRowValidationEventArgs is the data class for the following events:
The GridControl validates changes made within the focused row when you try to move focus to another row. Handle the GridViewBase.ValidateRow event to process the row validate operation.
The Row and RowHandle properties return the processed row and the row’s handle, respectively.
You can obtain cell values and verify if they meet your validation criteria. If these values are incorrect, set the IsValid property to false.
Refer to the following topic for more information: Row Validation.
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.
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;
}
}
Public Class Task
Implements IDataErrorInfo
Public Property TaskName As String
Public Property StartDate As Date
Public Property EndDate As Date
Private ReadOnly Property [Error] As String Implements IDataErrorInfo.[Error]
Get
Return If(StartDate > EndDate, "Either Start Date or End Date should be corrected.", Nothing)
End Get
End Property
Private ReadOnly Property Item(ByVal columnName As String) As String Implements IDataErrorInfo.Item
Get
Select Case columnName
Case NameOf(Task.StartDate)
If StartDate > EndDate Then Return "Start Date must be less than End Date"
Case NameOf(Task.EndDate)
If StartDate > EndDate Then Return "End Date must be greater than Start Date"
Case NameOf(Task.TaskName)
If String.IsNullOrEmpty(TaskName) Then Return "Enter a task name"
End Select
Return Nothing
End Get
End Property
End Class
Public Partial Class MainWindow
Inherits Window
' ...
Private Sub OnValidateRow(ByVal sender As Object, ByVal e As GridRowValidationEventArgs)
Dim task = CType(e.Row, Task)
If task.StartDate > task.EndDate Then e.SetError("Start Date must be less than End Date")
If String.IsNullOrEmpty(task.TaskName) Then e.SetError("Enter a task name")
End Sub
Private Sub OnInvalidRowException(ByVal sender As Object, ByVal e As InvalidRowExceptionEventArgs)
e.ExceptionMode = ExceptionMode.NoAction
End Sub
End Class
Object EventArgs RoutedEventArgs ValidationEventArgs GridRowValidationEventArgs GridCellValidationEventArgs
TreeListNodeValidationEventArgs
TreeListCellValidationEventArgs
See Also