WPF Foreground Color in a DataGrid, Change via Code (C#)?

Question

Hi,
I need to Change a Foreground Color in a DataGrid Line, here ist the XAML Code from the Line in the DataGrid:

                   <DataGridTemplateColumn Header="Nr " Width="38" CanUserSort="True" x:Name="SP001" >
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <Label x:Name="SP001F" Height="50" Content="{Binding GrLaufendePosition}" Foreground="Black" Background="White" HorizontalAlignment="Center" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" BorderThickness="0" VerticalAlignment="Center"  />
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>

SP001.Foreground = "Red"; is wrong :-(
SP001F.Foreground = "Red"; is wrong too :-(

Have anyone a idea?

Best Regards

Bernd

Answer 1

There are many ways to do this, but the easier way is to refer with DynamicResource.

<DataGrid x:Name="dataGrid1" >
    <DataGrid.Resources>
        <SolidColorBrush Color="Black" x:Key="columnForeground"/>
    </DataGrid.Resources>

    <DataGrid.Columns>
        <DataGridTemplateColumn Header="Nr " Width="38" CanUserSort="True" x:Name="SP001" >
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate >
                    <Label x:Name="SP001F" 
                    Height="50" 
                    Content="{Binding GrLaufendePosition}"

                    Foreground="{DynamicResource columnForeground}" 

                    Background="White" 
                    HorizontalAlignment="Center" 
                    HorizontalContentAlignment="Center" 
                    VerticalContentAlignment="Center" 
                    BorderThickness="0" 
                    VerticalAlignment="Center"/>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>


this.dataGrid1.Resources["columnForeground"] = Brushes.Red;

Answer 2

I Change my Code:

                <DataGrid.Resources>

                    <SolidColorBrush Color="Black" x:Key="columnForeground"/>
                    <SolidColorBrush Color="Transparent" x:Key="columnBackground"/>

                </DataGrid.Resources>


...

                    <DataGridTemplateColumn Header="Nr " Width="38" CanUserSort="True" x:Name="SP001">
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <Label x:Name="SP001F" 
                                       Height="50" 
                                       Content="{Binding GrLaufendePosition}" 

                                       Foreground="{DynamicResource columnForeground}"  
                                       Background="{DynamicResource columnBackground}"  

                                       HorizontalAlignment="Center" 
                                       HorizontalContentAlignment="Center" 
                                       VerticalContentAlignment="Center" 
                                       BorderThickness="0" 
                                       VerticalAlignment="Center" 
                                       Padding="0" RenderTransformOrigin="0,0" TextOptions.TextHintingMode="Fixed"  />
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>

…

            this.dg.Resources["columnForeground"] = Brushes.HotPink;
            this.dg.Resources["columnBackground"] = Brushes.LightBlue;

What is here wrong?

Answer 3

In a bound column for a datagrid in wpf if you want to change the color of some of the rows use a IValueConverter. This interface allows you to bind to a property and in this example change the brush used for the forground.

   public class ColorConverter : IValueConverter
   {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            int id = 0;

            if (value != null && int.TryParse(value.ToString(), out id))
           {
                 if (id == 3)
                 {
                      return new SolidColorBrush(Colors.Red);
                 }
           }

           return new SolidColorBrush(Colors.Black);
        }


         public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
         {
               throw new NotImplementedException();
         }
   }

To use this in the Xaml. First register it as a resource

   <Window.Resources>
         <local:ColorConverter x:Key="ColorConverter" />
   </Window.Resources>

Then in the binding you can use the converter

       <DataGridTemplateColumn Header="Name" Width="380" CanUserSort="True">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <Label Height="50"
                           Content="{Binding Name}"

                           Foreground="{Binding id, Converter={StaticResource ColorConverter}}"

                           Background="White"
                           HorizontalAlignment="Center"
                           HorizontalContentAlignment="Center"
                           VerticalContentAlignment="Center"
                           BorderThickness="0"
                           VerticalAlignment="Center" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>

Answer 4

SUPER!
That is what i Need :-)
And the Background is then "columnBackground" … !?

Answer 5

But if i change the Colors then i become this (the Colors of the fields are now ok...)

The Background is White!?
This is NOT the db.Background Color...
It must be anythink like ROW or Column Background?