R – How to bind WPF Datagrid itemssource to Collection of Collections

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What is the best approach to bind a WPF DataGrid ItemsSource to an ObservableCollection of ObservableCollections ?

e.g.

public ObservableCollection<ObservableCollection<MyDataItem>> DataValues = new ObservableCollection<ObservableCollection<MyDataItem>>();

where MyDataItem may look like this:

public class MyDataItem
{
    public string Caption { get; set; }
    public string DataValue { get; set; }
}

I can assume the collection of collections isn't jagged, and they all contain the same number of "columns"

Is it possible to bind each column dynamically to the 'DataValue' property of the MyDataItem objects or do I need to pack the data into an easier structure to bind to?

Best Answer

This is possible by using a collection-derived class as the inner object, and implementing ICustomTypeDescriptor on it - See a similar SO question on the topic (tagged with Silverlight, but same idea)

Silverlight DataGrid - Binding to a Collection of Collections of objects.

Related Solutions

R – Different cell styling in a wpf datagrid depending on datatype in the ItemsSource

Yes, it is possible to do it in several ways. The one I would go for is writing your own custom "typeswitch" converter that selects a value depending on type of input. Like this:

public class TypeSwitchConverter : Dictionary<Type, object>, IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, .CultureInfo culture)
    {
        foreach (var mapping in this)
        {
            if (mapping.Key.IsAssignableFrom(value.GetType()))
            {
                return mapping.Value;
            }
        }

        return null;
    }

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

And then use a binding for the Style of the top-level element in template for your cell, and use the above converter for that binding as needed. Here's a simplified example that styles items in a ListBox using it:

    <ListBox ItemsSource="{Binding}">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <TextBlock Text="{Binding}">
                    <TextBlock.Style>
                        <Binding>
                            <Binding.Converter>
                                <my:TypeSwitchConverter>
                                    <Style x:Key="{x:Type cor:Int32}" TargetType="{x:Type TextBlock}">
                                        <Setter Property="Background" Value="Red" />
                                    </Style>
                                    <Style x:Key="{x:Type cor:String}" TargetType="{x:Type TextBlock}">
                                        <Setter Property="Background" Value="Green" />
                                    </Style>
                                    <Style x:Key="{x:Type sys:Uri}" TargetType="{x:Type TextBlock}">
                                        <Setter Property="Background" Value="Blue" />
                                    </Style>
                                </my:TypeSwitchConverter>
                            </Binding.Converter>
                        </Binding>
                    </TextBlock.Style>
                </TextBlock>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>

C# WPF datagrid: ItemsSource

Answer to both questions is:

By looping through your datagrid
Access column by it's index

Best Answer

Related Solutions

R – Different cell styling in a wpf datagrid depending on datatype in the ItemsSource

C# WPF datagrid: ItemsSource

Related Topic