I&#39;ve got a `DataGrid` with a row that has an image. This image is bound with a trigger to a certain state. When the state changes I want to change the image.

The template itself is set on the `HeaderStyle` of a `DataGridTemplateColumn`. This template has some bindings. The first binding Day shows what day it is and the State changes the image with a trigger.

These properties are set in a ViewModel. 

Properties:

```c#
public class HeaderItem
{
    public string Day { get; set; }
    public ValidationStatus State { get; set; }
}

this.HeaderItems = new ObservableCollection&lt;HeaderItem&gt;();
for (int i = 1; i &lt; 15; i++)
{
    this.HeaderItems.Add(new HeaderItem()
    {
        Day = i.ToString(),
        State = ValidationStatus.Nieuw,
    });
}
```

Datagrid:

```xaml
&lt;DataGrid x:Name=&quot;PersoneelsPrestatiesDataGrid&quot; HorizontalAlignment=&quot;Stretch&quot; VerticalAlignment=&quot;Stretch&quot;
              AutoGenerateColumns=&quot;False&quot; SelectionMode=&quot;Single&quot; ItemsSource=&quot;{Binding CaregiverPerformances}&quot; FrozenColumnCount=&quot;1&quot; &gt;

    &lt;DataGridTemplateColumn HeaderStyle=&quot;{StaticResource headerCenterAlignment}&quot; Header=&quot;{Binding HeaderItems[1]}&quot; Width=&quot;50&quot;&gt;
        &lt;DataGridTemplateColumn.CellEditingTemplate&gt;
            &lt;DataTemplate&gt;
                &lt;TextBox Text=&quot;{ Binding Performances[1].Duration,Converter={StaticResource timeSpanConverter},Mode=TwoWay}&quot;/&gt;
            &lt;/DataTemplate&gt;
        &lt;/DataGridTemplateColumn.CellEditingTemplate&gt;

        &lt;DataGridTemplateColumn.CellTemplate&gt;
            &lt;DataTemplate&gt;
                &lt;TextBlock TextAlignment=&quot;Center&quot; Text=&quot;{ Binding Performances[1].Duration,Converter={StaticResource timeSpanConverter}}&quot;/&gt;
            &lt;/DataTemplate&gt;
        &lt;/DataGridTemplateColumn.CellTemplate&gt;
    &lt;/DataGridTemplateColumn&gt; 
&lt;/DataGrid&gt;
```

Datagrid HeaderStyleTemplate:

```xaml
&lt;Style x:Key=&quot;headerCenterAlignment&quot; TargetType=&quot;{x:Type DataGridColumnHeader}&quot;&gt;
    &lt;Setter Property=&quot;HorizontalContentAlignment&quot; Value=&quot;Center&quot;/&gt;

    &lt;Setter Property=&quot;Template&quot;&gt;
        &lt;Setter.Value&gt;
            &lt;ControlTemplate TargetType=&quot;{x:Type DataGridColumnHeader}&quot;&gt;
                &lt;Grid&gt;
                    &lt;Grid.RowDefinitions&gt;
                        &lt;RowDefinition /&gt;
                        &lt;RowDefinition /&gt;
                    &lt;/Grid.RowDefinitions&gt;

                    &lt;TextBlock Grid.Row=&quot;0&quot; Text=&quot;{Binding Day}&quot; /&gt;
                    &lt;Image x:Name=&quot;imageValidation&quot; Grid.Row=&quot;1&quot; Width=&quot;16&quot; Height=&quot;16&quot; Source=&quot;{StaticResource imgBevestigd}&quot; /&gt;
                &lt;/Grid&gt;

                &lt;ControlTemplate.Triggers&gt;
                    &lt;MultiDataTrigger &gt;
                        &lt;MultiDataTrigger.Conditions&gt;
                            &lt;Condition Binding=&quot;{Binding State}&quot; Value=&quot;Nieuw&quot;/&gt;                                 
                        &lt;/MultiDataTrigger.Conditions&gt;
                        &lt;Setter TargetName=&quot;imageValidation&quot; Property=&quot;Source&quot; Value=&quot;{StaticResource imgGeenStatus}&quot;/&gt;
                    &lt;/MultiDataTrigger&gt;
                &lt;/ControlTemplate.Triggers&gt;
            &lt;/ControlTemplate&gt;
        &lt;/Setter.Value&gt;
    &lt;/Setter&gt;
&lt;/Style&gt;
```

Now when I startup the project the images doesn&#39;t show and I get this error:

&gt;System.Windows.Data Error: 2 : Cannot find governing FrameworkElement or FrameworkContentElement for target element. BindingExpression:Path=HeaderItems[0]; DataItem=null; target element is &#39;DataGridTemplateColumn&#39; (HashCode=26950454); target property is &#39;Header&#39; (type &#39;Object&#39;)

Why is this error showing?


All Multidatatrigger Solutions on Gang of Coders

Total of 1 Multidatatrigger Solutions

WPF Error: Cannot find governing FrameworkElement for target element