CODEWITHSUNDEEP
c#wpfcomboboxbindingdatagrid
A. H
A. H

Reputation: 47

C# WPF DataGrid: DataGridComboxBoxColumn Binding ItemsSource failed

i want to display a ComboBox on my DataGrid. But the ComboBox does not load the ObservableCollection. My ObservableCollection 'Projects' is on my ViewModel defined. The problem is not the DataContext. But when I define the ComboBox outside of my DataGrid, the binding works. Does anyone have an idea where my problem is?

ViewModel:

public Project SelectedProject
{
    get { return _project; }
    set
    {
        if (_project != value)
        {
            _project = value;
            OnPropertyChanged();
            _actions = _database.LoadActions(SelectedProject.Id);
            OnPropertyChanged(() => Actions);
        }
    }
}

public ObservableCollection<Project> Projects
{
    get { return _database.LoadProjects(); }
}

XAML:

<DataGridComboBoxColumn Header="Projekt:" Width="140" DisplayMemberPath="Name">
    <DataGridComboBoxColumn.ElementStyle>
        <Style TargetType="ComboBox">
            <Setter Property="ItemsSource" Value="{Binding Projects, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}"/>
            <Setter Property="SelectedItem" Value="{Binding SelectedProject, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
        </Style>
    </DataGridComboBoxColumn.ElementStyle>
    <DataGridComboBoxColumn.EditingElementStyle>
        <Style TargetType="ComboBox">
            <Setter Property="ItemsSource" Value="{Binding Projects, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" />
            <Setter Property="SelectedItem" Value="{Binding SelectedProject, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
            <Setter Property="IsDropDownOpen" Value="True" />
        </Style>
    </DataGridComboBoxColumn.EditingElementStyle>

Upvotes: 0

Views: 186

Answers (1)

mm8
mm8

Reputation: 169200

Try this:

<Setter Property="ItemsSource" Value="{Binding DataContext.Projects, RelativeSource={RelativeSource AncestorType=DataGrid}}"/>

The DataContext of the ComboBox in a DataGridComboBoxColumn is the corresponding object in the DataGrid's ItemsSource.

If your Projects collection is defined in the view model, you need to specify a RelativeSource for the binding to work.

Upvotes: 1

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