C＃WPF DataGridCheckboxColumn检查一次检查很多

Question

我在使用DataGridCheckBoxColumn时遇到一些问题。对于某些单元格，当我选中一个复选框时，会同时检查多个复选框。我应该如何防止这种情况？这是我的XAML。

<DataGrid IsReadOnly="True" Margin="10,0,10,8" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Grid.Row="2" Name="newsStories" AutoGenerateColumns="False" RowHeaderWidth="0">
    <DataGrid.Columns>
        <DataGridTextColumn Width="8*" Header="Headline" Binding="{Binding Path=heading}">
            <DataGridTextColumn.HeaderStyle>
                <Style TargetType="DataGridColumnHeader">
                    <Setter Property="HorizontalContentAlignment" Value="Center" />
                </Style>
            </DataGridTextColumn.HeaderStyle>
            <DataGridTextColumn.ElementStyle>
                <Style>
                    <Setter Property="TextBlock.TextWrapping" Value="Wrap" />
                    <Setter Property="TextBlock.Padding" Value="5" />
                </Style>
            </DataGridTextColumn.ElementStyle>
        </DataGridTextColumn>
        <DataGridCheckBoxColumn Header="Select" Width="2*" Binding="{Binding Path=isIncluded, Mode=OneWayToSource, UpdateSourceTrigger=PropertyChanged}">
            <DataGridCheckBoxColumn.HeaderStyle>
                <Style TargetType="DataGridColumnHeader">
                    <Setter Property="HorizontalContentAlignment" Value="Center" />
                </Style>
            </DataGridCheckBoxColumn.HeaderStyle>
            <DataGridCheckBoxColumn.ElementStyle>
                <Style>
                    <Setter Property="TextBlock.HorizontalAlignment" Value="Center" />
                    <Setter Property="TextBlock.VerticalAlignment" Value="Center" />
                </Style>
            </DataGridCheckBoxColumn.ElementStyle>
            <DataGridCheckBoxColumn.CellStyle>
                <Style>
                    <EventSetter Event="CheckBox.Checked" Handler="handleChecked" />
                    <EventSetter Event="CheckBox.Unchecked" Handler="handleChecked" />
                </Style>
            </DataGridCheckBoxColumn.CellStyle>
        </DataGridCheckBoxColumn>
    </DataGrid.Columns>
</DataGrid>

我没有任何代码隐藏在这里显示。问题出在这里，即使我没有任何代码隐藏。

谢谢。