C＃WPF DataGrid将行背景绑定到DataRow中找到的属性

Question

I need to bind a background of a DataRow, to a property of an object attached to the DataRow. What I have done is:

I have extended the DataRow class, to have a 'Tag' property which is of type [object].

Example:

myDataTable.Rows.Cast<ExtendedDataRow>().ToList(){r => {
    r.Tag = Brushes.Green;
});

So basically for every Row, there is a Tag property which is a Brush, Green. I need to bind my DataTable to this dataset, and bind each row to the Tag property.

What I have tried:

<DataGrid ItemsSource="{Binding myDataTable}">
    <DataGrid.RowStyle>
        <Style TargetType="DataGridRow">
            <Setter Property="Background" Value="{Binding Tag.Background}" />
        </Style>
    </DataGrid.RowStyle>
</DataGrid>

But it does not seem to 'pick up' the Tag item when I am trying to bind to it. Do I need to create an ItemTemplate for this? (I have tried it, also did not work)

: The dataset is binding successfully, and in the code in the ViewModel I can see the Tag items for each row is populated.

Thanks in advance

: It has been requested to see how my ExtendedDataRow class is used:

public class ExtendedDataTable : DataTable {
    public ExtendedDataTable()
        : base() {
    }

    public ExtendedDataTable(string tableName)
        : base(tableName) {
    }

    public ExtendedDataTable(string tableName, string tableNamespace)
        : base(tableName, tableNamespace) {
    }

    // Return the RowType as ExtendedDataRow instead of DataRow
    protected override Type GetRowType() {
        return typeof(ExtendedDataRow);
    }

    // Use the RowBuilder to return an ExtendedDataRow instead of DataRow
    protected override DataRow NewRowFromBuilder(DataRowBuilder builder) {
        return new ExtendedDataRow(builder);
    }
}

public class ExtendedDataRow : DataRow {
    public ExtendedDataRow()
        : base(null) {
    }

    public ExtendedDataRow(DataRowBuilder rb)
        : base(rb) {
    }

    // The tag object attached to the ExtendedDataRow
    public object Tag { get; set; }
}

: To bind to the ExtendedDataTable instead of a normal DataTable, you have to fill a normal DataTable, and use its IDataReader to fill the dataset of the ExtendedDataTable:

myDt = new ExtendedDataTable();
dt = new DataTable();
var dt = GetDataTable("SELECT * FROM SomeTable");
var reader = dt.DataSet.CreateDataReader(dt);
myDt.Load(reader);

Answer 1

I did every thing as expected , just like you've done .

I noticed the problem by looking in the output window :

      System.Windows.Data Error: 40 : BindingExpression path error: 'Tag' property not found on 'object' ''DataRowView' (HashCode=30296746)'. BindingExpression:Path=Tag; DataItem='DataRowView' (HashCode=30296746); target element is 'DataGridRow' (Name=''); target property is 'Background' (type 'Brush')

DataRow is some how internally wrapped with something called a DataRowView

A quick glance in msdn - DataRowView.Row

XAML :

  <DataGrid CanUserAddRows="False" ItemsSource="{Binding Table}">                     
        <DataGrid.RowStyle>
            <Style TargetType="DataGridRow">
                <Setter Property="Background" Value="{Binding Row.Tag, Mode=OneWay}" />
            </Style>
        </DataGrid.RowStyle>
    </DataGrid>