Prevent updation to ObservableCollection on Error - wpf

Question

Is there a way to prevent updating to ObservableCollection list when there is an validation error in xaml? I am using "Binding" in the xaml
my xaml
<ControlTemplate x:Key="ErrorTemplate">
<DockPanel LastChildFill="True">
<Border BorderBrush="Red" BorderThickness="1">
<AdornedElementPlaceholder />
</Border>
</DockPanel>
</ControlTemplate>
<Style TargetType="TextBlock">
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="ToolTip"
Value="{Binding RelativeSource={x:Static RelativeSource.Self}, Path=(Validation.Errors)[0].ErrorContent}"/>
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources>
<DataGrid Name="grid" HorizontalAlignment="Stretch" ItemsSource="{Binding mMngModelList}" Margin="0,0,0,50" VerticalAlignment="Stretch" AutoGenerateColumns="False" CanUserAddRows="False">
<DataGrid.Columns>
<DataGridTemplateColumn Header="Name">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<TextBox Text="{Binding Name}" />
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Type">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Type}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<TextBox Text="{Binding Type}" />
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Range Left">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding RangeLeft,ValidatesOnDataErrors=True, NotifyOnValidationError=True, ValidatesOnExceptions=True}" Validation.ErrorTemplate="{StaticResource ErrorTemplate}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<TextBox Text="{Binding RangeLeft, ValidatesOnDataErrors=True, NotifyOnValidationError=True, ValidatesOnExceptions=True}" Validation.ErrorTemplate="{StaticResource ErrorTemplate}"/>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
code behind is
public string this[string columnName]
{
get
{
var result = string.Empty;
switch (columnName)
{
case "RangeLeft":
if (RangeLeft == 0)
{
result = "RangeLeft should be greater than zero";
}
break;
}
return result;
}
}
public string Error
{
get
{
StringBuilder error = new StringBuilder();
// iterate over all of the properties
// of this object - aggregating any validation errors
PropertyDescriptorCollection props = TypeDescriptor.GetProperties(this);
foreach (PropertyDescriptor prop in props)
{
String propertyError = this[prop.Name];
if (propertyError != string.Empty)
{
error.Append((error.Length != 0 ? ", " : "") + propertyError);
}
}
return error.Length == 0 ? null : error.ToString();
}
}
The above code is to display error in the tooltip and the cell goes red when there is a validation error. The problem is that the collection is updated with invalid values. Is there a way to prevent updation to the collection till all validation is resolved by the user?

Answer 1

you can solve your problem by clone the object that is enter in the editing mode, when there is validation return cloning object and make refresh on DataGrid Items