Accessing a combo box property inside a datagrid in wpf

Question

I have a datagrid which has four columns of combobox in wpf. At the starting, the first combobox is enabled. After making a selection on the first combobox, the second combobox gets enabled. I am unable to access the combobox name property in my xaml.cs file so that I can enable the next combobox column after successful selection of the first one. Can you suggest how to access the combobox property which is present inside a datagrid in my xaml.cs file ?

This is my xaml code

<DataGridTemplateColumn     
    Header ="Example 9">
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <ComboBox ItemsSource="{Binding PartIds, RelativeSource={RelativeSource AncestorType=Window}}" SelectedItem ="{Binding PartId,UpdateSourceTrigger=PropertyChanged}" />
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

Answer 1

Assuming you have two columns in your DataGrid , the first column contains a combobox , and its selecteditem is bound to a property named PartId , the second column contains also a combobox with a selecteditem bound to a property named PartId2 , your model should look something like that:

public class Model
{
    public string PartId { get; set; }
    public string PartId2 { get; set; }
}

Now, assuming your DataGrid 's itemsource is bound to an ObservableCollection named DgCollection :

 private ObservableCollection<Model> _dgCollection;
 public ObservableCollection<Model> DgCollection
    {
        get { return _dgCollection; }
        set
        {
            if (Equals(value, _dgCollection)) return;
            _dgCollection = value;
            OnPropertyChanged();
        }
    }

The second column could use a DataTrigger to activate its combobox once the selecteditem of the first column is set, like so:

<DataGrid ItemsSource="{Binding DgCollection}" AutoGenerateColumns="False">
    <DataGrid.Columns>
        <DataGridTemplateColumn     
    Header ="Example 9">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <ComboBox ItemsSource="{Binding PartIds, RelativeSource={RelativeSource AncestorType=Window}}" SelectedItem ="{Binding PartId,UpdateSourceTrigger=PropertyChanged}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
        <DataGridTemplateColumn     
            Header ="Example 10">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <ComboBox x:Name="FirstCbx" ItemsSource="{Binding PartIds, RelativeSource={RelativeSource AncestorType=Window}}" SelectedItem ="{Binding PartId2,UpdateSourceTrigger=PropertyChanged}" >
                        <ComboBox.Style>
                            <Style TargetType="ComboBox">
                                <Setter Property="IsEnabled" Value="True"/>
                                <Style.Triggers>
                                    <DataTrigger Binding="{Binding PartId}" Value="{x:Null}">
                                        <Setter Property="IsEnabled" Value="False"/>
                                    </DataTrigger>
                                </Style.Triggers>
                            </Style>
                        </ComboBox.Style>
                    </ComboBox>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

You could generalize this to four columns easily.