DataGrid：使用转换器更改单元格颜色

Question

I have a WPF DataGrid bound to a DataView I create from a DataTable . The DataTable cells are a custom object ( TableCellDifference ) that have some information I'd like to color code.

Here is the xaml

<DataGrid ItemsSource="{Binding Path=SelectedTableView}" Grid.Column="2" 
    <DataGrid.CellStyle>
        <Style TargetType="{x:Type DataGridCell}">
            <Style.Setters>
                <Setter Property="Background" Value="{Binding Converter={StaticResource converter}}" />
            </Style.Setters>
        </Style>
    </DataGrid.CellStyle>
</DataGrid> 

The convert method is actually getting called. What I'm curious about, though, is why it's getting called on DataRowView rather than a DataGridCell , as declared in the trigger.

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var dataRow = value as DataRowView;
        if (dataRow == null) return null;

        // why does the cast to DataRowView succeed? It
        // seems like this method should be targeting the cell objects
        foreach (object item in dataRow.Row.ItemArray) 
        {
            var cast = item as TableCellDifference;
            if (cast == null) continue;

            switch(cast.Type)
            {
                case TableCellDifferenceType.Addition:
                    return Brushes.LightGreen;

                case TableCellDifferenceType.Mismatch:
                case TableCellDifferenceType.Omission:
                    return Brushes.Red;

                default:
                    return Brushes.White;
            }
        }
        return null;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

Is this the correct way of doing things?

Answer 1

Converter will take the value coming as a result of Binding. As you are using DataView as your ItemsSource , and DataView is comprised of DataRowView objects. So, you are getting DataRowView as source in your Converter.

Answer 2

The converter name is too much generic and can be a problem. Instead use "CellStyleConverter" as name for example.