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【笔记】WPF中如何的动态设置DataGridTextColumn是否显示

news 2025/10/11 6:26:01

要动态控制 DataGridTextColumn 是否显示，不能用普通触发器或直接绑定，因为列不在可视树中。做法是：

给列挂“可绑定的可见性”附加属性；
用绑定把该属性连到一个状态值（如 ViewModel 的 SelectedTabItemData.State 或当前选中行的 State）；
用转换器把状态转成 Visible/Collapsed。

示例：

<UserControl x:Class="H.Sxb.Modules.Bill.View.OrderBillControl"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:b="http://schemas.microsoft.com/xaml/behaviors"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:local="clr-namespace:H.Sxb.Modules.Bill.View"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"xmlns:sys="clr-namespace:System;assembly=mscorlib"mc:Ignorable="d"><UserControl.Resources><local:IntInSetToVisibilityConverter x:Key="IntInSetToVisibilityConverter" /><local:BindingProxy x:Key="dgProxy" Data="{Binding}" /></UserControl.Resources><!-- ... --><DataGrid x:Name="dg"ItemsSource="{Binding PageResponse.Items}"><DataGrid.Columns><!-- 顶部表格：当 State 为 1/2/3 显示“实发金额”，为 2/3 显示“收货金额” --><DataGridTextColumn Binding="{Binding MinusAmount}"Header="实发金额"local:DataGridColumnExtensions.BindableVisibility="{Binding Data.SelectedTabItemData.State,Source={StaticResource dgProxy},Converter={StaticResource IntInSetToVisibilityConverter},ConverterParameter=1,2,3}" /><DataGridTextColumn Binding="{Binding ReceivableAmount}"Header="收获金额"local:DataGridColumnExtensions.BindableVisibility="{Binding Data.SelectedTabItemData.State,Source={StaticResource dgProxy},Converter={StaticResource IntInSetToVisibilityConverter},ConverterParameter=2,3}" /><!-- 其余列... --></DataGrid.Columns></DataGrid>
</UserControl>

IntInSetToVisibilityConverter

using System;
using System.Globalization;
using System.Linq;
using System.Windows;
using System.Windows.Data;namespace H.Sxb.Modules.Bill.View
{public class IntInSetToVisibilityConverter : IValueConverter{public bool Invert { get; set; }public object Convert(object value, Type targetType, object parameter, CultureInfo culture){var text = parameter?.ToString() ?? string.Empty;var set = text.Split(new[] { ' '}, StringSplitOptions.RemoveEmptyEntries).Select(s => s.Trim()).ToArray();var val = value?.ToString();var match = set.Any(s => string.Equals(s, val, StringComparison.OrdinalIgnoreCase));if (Invert) match = !match;return match ? Visibility.Visible : Visibility.Collapsed;}public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) =>Binding.DoNothing;}
}

DataGridColumnExtensions

using System.Windows;
using System.Windows.Controls;namespace H.Sxb.Modules.Bill.View
{public static class DataGridColumnExtensions{public static readonly DependencyProperty BindableVisibilityProperty =DependencyProperty.RegisterAttached("BindableVisibility",typeof(Visibility),typeof(DataGridColumnExtensions),new PropertyMetadata(Visibility.Visible, OnBindableVisibilityChanged));public static void SetBindableVisibility(DependencyObject obj, Visibility value) =>obj.SetValue(BindableVisibilityProperty, value);public static Visibility GetBindableVisibility(DependencyObject obj) =>(Visibility)obj.GetValue(BindableVisibilityProperty);private static void OnBindableVisibilityChanged(DependencyObject d, DependencyPropertyChangedEventArgs e){if (d is DataGridColumn column && e.NewValue is Visibility v)column.Visibility = v;}}
}

BindingProxy

using System.Windows;namespace H.Sxb.Modules.Bill.View
{// Freezable proxy to expose DataContext into places not in the visual tree (e.g., DataGridColumn)public class BindingProxy : Freezable{public object Data{get => GetValue(DataProperty);set => SetValue(DataProperty, value);}public static readonly DependencyProperty DataProperty =DependencyProperty.Register(nameof(Data), typeof(object), typeof(BindingProxy), new UIPropertyMetadata(null));protected override Freezable CreateInstanceCore() => new BindingProxy();}
}

要点

DataGridColumn 不在可视树，必须用附加属性设置列的 Visibility。请确保使用命名空间前缀：local:DataGridColumnExtensions.BindableVisibility。
绑定源可用 BindingProxy 暴露的 DataContext（你已加 dgProxy，继续沿用即可）。
ConverterParameter 建议逗号分隔（1,2,3）。如果你的 IntInSetToVisibilityConverter 已实现空格分隔，也可保持空格。
若需“按行”显示/隐藏，请改用 DataGridTemplateColumn，在 CellTemplate 内用 DataTrigger 控制单元内容的 Visibility。