CODEWITHSUNDEEP
c#wpfvalidationxamldatagrid
M.Khamis
M.Khamis

Reputation: 21

c# WPF determine if DataGrid default visual validation has errors

I am a newbie in WPF, I have always done validation for various UI controls using custom ValidationRule classes, however, when using DataGrid for the first time and binding it with a simple DataTable, I found that the DataGrid has a pretty good default validation that detects the type of DataTable columns and gives a visual error if a cell value is not of the same expected type. This is pretty enough for me that I thought no need to create custom validation rules as the default one is fitting my purpose. However, I have a Submit button that I need to disable if this DataGrid has any errors, so I thought that this would be easy utilizing the Validation.HasError property using the following code:

<Button x:Name="btnSubmit" Content="Submit">
        <Button.Style>
            <Style TargetType="Button">
                <Setter Property="IsEnabled" Value="False"/>
                <Style.Triggers>
                    <MultiDataTrigger>
                        <MultiDataTrigger.Conditions>
                            <Condition Binding="{Binding Path=(Validation.HasError),ElementName=dataGrid}" Value="False"/>
                        </MultiDataTrigger.Conditions>
                        <Setter Property="IsEnabled" Value="True"/>
                    </MultiDataTrigger>
                </Style.Triggers>
            </Style>
        </Button.Style>
    </Button>

But unfortunately, it seems that Validation.HasError is always False whatever the value I enter in the datagrid cells in Runtime. The default visual validation is working properly, the cell gets a red border when an incorrect value is entered, however, no notification is sent that there is an error coming from the dataGrid.

Is there any way to detect within XAML that the default visual validation of the dataGrid is producing an error? or do I have to use a custom validation rule for this purpose?

Upvotes: 2

Views: 570

Answers (1)

Guilherme Fidelis
Guilherme Fidelis

Reputation: 1020

You can create a global validation on your Ap.xaml file. So Your control will have a red asterisk and the error message as Tooltip . Any control of your project can use the same validation.

In App.xaml file:

 <Style x:Key="AsteriskTemplate" TargetType="Control">
        <Setter Property="Validation.ErrorTemplate">
            <Setter.Value>
                <ControlTemplate>
                    <DockPanel LastChildFill="True">
                        <TextBlock DockPanel.Dock="Right"
                           Foreground="Red"
                           FontSize="14pt"
                           Margin="-15,0,0,0" FontWeight="Bold">*
                        </TextBlock>                            
                        <Border>
                            <AdornedElementPlaceholder Name="myControl"/>
                        </Border>
                    </DockPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <Trigger Property="Validation.HasError" Value="true">
                <Setter Property="ToolTip"
                    Value="{Binding RelativeSource={x:Static RelativeSource.Self},
                    Path=(Validation.Errors).CurrentItem.ErrorContent}"/>
            </Trigger>
        </Style.Triggers>
    </Style>


 <Style TargetType="DataGrid" BasedOn="{StaticResource AsteriskTemplate}" />

Upvotes: 0

Related Questions