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场景：根据配置文件显示DataGrid中的某些列。
问题：Columns集合只是DataGrid的一个属性，这个集合在逻辑树或视觉树中是看不到的，也不会继承DataContext属性。
通过网上查阅各种资料，方法可以归结以下几种，下面将一一展示。
方法一：对DataGridColumn附加DataContext属性
该方法需要用到一个帮助类（需要创建一个全局实例），具体内容如下：
public class DataGridContextHelper { static DataGridContextHelper() { DependencyProperty dp = FrameworkElement.DataContextProperty.AddOwner(typeof(DataGridColumn)); FrameworkElement.DataContextProperty.OverrideMetadata(typeof(DataGrid), new FrameworkPropertyMetadata (null, FrameworkPropertyMetadataOptions.Inherits, new PropertyChangedCallback(OnDataContextChanged))); } public static void OnDataContextChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { DataGrid grid = d as DataGrid; if (grid != null) { foreach (DataGridColumn col in grid.Columns) { col.SetValue(FrameworkElement.DataContextProperty, e.NewValue); } } } }
前台绑定示例
<DataGridTextColumn x:Name="col2" Header="TestColumn" Visibility="{Binding (FrameworkElement.DataContext).Show,RelativeSource={RelativeSource Self},Converter={StaticResource cc}}"></DataGridTextColumn>
后台绑定示例
var binding = new Binding(); binding.Mode = BindingMode.OneWay; binding.RelativeSource=new RelativeSource(RelativeSourceMode.Self); binding.Converter = new BooleanToVisibilityConverter(); binding.Path=new PropertyPath("(FrameworkElement.DataContext).Show"); BindingOperations.SetBinding(obj, DataGridColumn.VisibilityProperty, binding);
方法二：通过Source直接与Vm绑定
示例代码：
var binding = new Binding(); binding.Mode = BindingMode.OneWay; binding.Source = vm; binding.Converter = new BooleanToVisibilityConverter(); binding.Path = new PropertyPath("Show"); BindingOperations.SetBinding(obj, DataGridColumn.VisibilityProperty, binding);
方法三：通过Source与VM的一个代理类进行绑定
代理类
Freezable可以继承DataContext即使它们不在视觉树或逻辑树中
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); } } public static readonly DependencyProperty DataProperty = DependencyProperty.Register("Data", typeof(object), typeof(BindingProxy)); }
前台绑定代码
<DataGrid x:Name="dg" HorizontalAlignment="Left" VerticalAlignment="Top" Height="253" Width="436" ItemsSource="{Binding Persons}" AutoGenerateColumns="False"> <DataGrid.Resources> <dgTest:BindingProxy x:Key="proxy" Data="{Binding}"/> </DataGrid.Resources> <DataGrid.Columns> <DataGridTextColumn x:Name="col1" Header="TestColumn" Binding="{Binding Name}"></DataGridTextColumn> <DataGridTextColumn x:Name="col2" Header="TestColumn" Visibility="{Binding (FrameworkElement.DataContext).Show,RelativeSource={RelativeSource Self},Converter={StaticResource cc}}"></DataGridTextColumn> <DataGridTextColumn x:Name="col3" Header="TestColumn" Visibility="{Binding Data.Show,Source={StaticResource proxy},Converter={StaticResource cc}}"></DataGridTextColumn> </DataGrid.Columns> </DataGrid>
方法四：通过一个代理控件来实现
代理控件与代理对象的解决方式类似，都是因为其可以继承DataContext属性，只是一个在逻辑树中看的到，一个看不到。示例如下：
<FrameworkElement x:Name="dummyElement" Visibility="Collapsed"/> <DataGrid> <DataGrid.Columns> <DataGridTextColumn Header="Test" Binding="{Binding Name}" Visibility="{Binding DataContext.IsEnable, Source={x:Reference dummyElement}}"/> </DataGrid.Columns> </DataGrid>
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原文地址：http://www.cnblogs.com/maigc249/p/4561079.html
