Popup to edit complex property of a data grid

Question

I am developing a WPF application that uses a datagrid to display a list of objects. A few of the columns are displaying properties with deeper information, I would like to display a summary value in the data grid, and then display a deeper window when clicked to allow editing properties.

I am part way to what I want, in that my data grid displays what I want and that I can make a dialog box appear when one of my special columns are clicked.

<DataGrid ItemsSource="{Binding Sequence.Steps}" AutoGenerateColumns="False" IsReadOnly="True" SelectionUnit="Cell">
    <DataGrid.Resources>
        <Style TargetType="DataGridCell">
            <EventSetter Event="PreviewMouseDown" Handler="DataGrid_PreviewMouseDown" />
            <Setter Property="Focusable" Value="False" />
        </Style>
    </DataGrid.Resources>
    <DataGrid.Columns>
        <DataGridTextColumn Header="Axis 1" Binding="{Binding Axes[0]}" ClipboardContentBinding="{Binding Axes[0].DestinationSP}" Width="*" />
        <DataGridTextColumn Header="Axis 2" Binding="{Binding Axes[1]}" ClipboardContentBinding="{Binding Axes[1].DestinationSP}" Width="*"/>
        <DataGridTextColumn Header="Axis 3" Binding="{Binding Axes[2]}" ClipboardContentBinding="{Binding Axes[2].DestinationSP}" Width="*"/>
    </DataGrid.Columns>
</DataGrid>

I have then defined a handler

private void DataGrid_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
    var dlg = new Views.EditAxisMovement(CellValue); // Need to find a way to get Cell value so I can pass it
    dlg.Owner = this;
    dlg.ShowDialog();
}

However I cant find the right way to find CellValue to pass to the dialog box. Is there a nice and/or better way of handling this.

Answer 1

You could create a DataGridCellInfo and check the header of the column to map the cell against a property of your data item, e.g.:

private void DataGrid_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
    DataGridCell cell = (DataGridCell)sender;
    DataGridCellInfo cellInfo = new DataGridCellInfo(cell);
    string header = cellInfo.Column.Header?.ToString();
    int index = -1;
    switch (header)
    {
        case "Axis 1":
            index = 0;
            break;
        case "Axis 2":
            index = 1;
            break;
        case "Axis 3":
            index = 2;
            break;
    }
    if (index != -1)
    {

    }

    var dataItem = cellInfo.Item as YourClass;
    object value = dataItem.Axes[index];
    //...
}