Can i use a different item source for a checkbox inside a DataGrid, which has already defined an ite-CodePudding

i am working on a wpf project in c# using the mvvm pattern. My problem is, that i have a datagrid in my main window which uses a collection of items as the item source. It is defined like this:

   <Border Grid.Column="1" Style="{StaticResource BorderStyle}" Padding="5">
                <DataGrid ItemsSource="{Binding SampleCollection.Samples}" 
                          AutoGenerateColumns="False"
                          CanUserAddRows="False"
                          Grid.Column="1" 
                          SelectedItem="{Binding Selected, Mode=TwoWay}"
                          SelectionMode="Single">

But now i need a checkbox in the header of the table which binds directly to a variable in the main window view model.

        <DataGrid.Columns>
                    <DataGridCheckBoxColumn
                        Binding="{Binding StrStatus, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" >
                        <DataGridCheckBoxColumn.Header>
                            <Grid>
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition/>
                                    <ColumnDefinition/>
                                </Grid.ColumnDefinitions>
                                <Grid Grid.Column="0">
                                    <CheckBox IsChecked="{Binding ActivateAllSampleSTR, Mode=TwoWay}" Background="AliceBlue" Height="16" VerticalAlignment="Top" />
                                </Grid>
                                <Grid Grid.Column="1">
                                    <TextBlock Text="STR-Status"/>
                                </Grid>
                            </Grid>
                        </DataGridCheckBoxColumn.Header>
                    </DataGridCheckBoxColumn>

The idea was to use a checkbox in the table header to set a boolean in the main view model, which triggers a function which sets all Status of the bound collection to true.

CodePudding user response：

You can bind your CheckBox.IsChecked to main view-model using RelativeSource to take DataContext of DataGrid itself, for example, like this:

IsChecked="{Binding DataContext.ActivateAllSampleSTR, Mode=TwoWay, RelativeSource={RelativeSource FindAncestor, AncestorType=DataGrid}}"

Or maybe simpler to have your DataGrid named, for example, <DataGrid x:Name='Grid' and then use:

IsChecked="{Binding DataContext.ActivateAllSampleSTR, Mode=TwoWay, ElementName=Grid}"