Wpf DataGridCheckBoxColumn 问题

使用DataGridCheckBoxColumn  binding一个布尔属性时，发现无法checkbox无法勾选， 并且HeaderTemplate中的checkbox无法获取到viewmodel的IsSelectAll属性，

最后通过下列方式解决。注意放大的部分

<DataGridCheckBoxColumn
                   x:Name="checkColumn"
                   Width=""
                   Binding="{Binding Path=IsSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                   CanUserSort="False"
                   IsReadOnly="False">
                    <DataGridCheckBoxColumn.ElementStyle>
                        <Style  TargetType="CheckBox" />
                    </DataGridCheckBoxColumn.ElementStyle>
                    <DataGridCheckBoxColumn.HeaderTemplate>
                        <DataTemplate>
                            <CheckBox IsChecked="{Binding Path=DataContext.IsSelectAll, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type DataGrid}}}" />
                        </DataTemplate>

                    </DataGridCheckBoxColumn.HeaderTemplate>
                </DataGridCheckBoxColumn>

方案二：

通过资源绑定

 public class BindingProxy : Freezable
    {
        #region Overrides of Freezable

        protected override Freezable CreateInstanceCore()
        {
            return new BindingProxy();
        }

        #endregion

        public object Data
        {
            get { return (object)GetValue(DataProperty); }
            set { SetValue(DataProperty, value); }
        }

        // Using a DependencyProperty as the backing store for Data.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty DataProperty =
            DependencyProperty.Register("Data", typeof(object), typeof(BindingProxy), new UIPropertyMetadata(null));
    }

添加资源
 <wpf:BindingProxy x:Key="proxy" Data="{Binding}" />

 <DataGridTemplateColumn  Visibility="{Binding Data.CanChooseMorePatients,Source={StaticResource proxy}, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource  CollapsedConverter}}" >
                        <DataGridTemplateColumn.Header>
                            <CheckBox IsChecked="{Binding Path=Data.IsAllPatientSelected,UpdateSourceTrigger=PropertyChanged, Source={StaticResource proxy} }" />
                        </DataGridTemplateColumn.Header>
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <CheckBox IsChecked="{Binding IsPatientSelected,Mode=OneWay,UpdateSourceTrigger=PropertyChanged}"  wpf:CheckboxHelper.PreMouseLeftButtonDownCommand="{Binding CheckedClickCommand}"  />
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>

  </DataGridTemplateColumn>