WPF:如何使用XAML隐藏GridViewColumn？

Question

我在App.xaml中有以下对象

<Application.Resources>
        <ResourceDictionary>
            <GridView x:Key="myGridView" x:Shared="false">
                             <GridViewColumn Header="Created" DisplayMemberBinding="{Binding Path=Created}"/>

... more code ...

我在多个地方使用这个网格视图.例:

<ListView x:Name="detailList"   View="{StaticResource myGridView}" ...>

在其中一个用法(例如上面的detailList)中,我想隐藏Created列,可能使用XAML？

有任何想法吗？

Answer 1

实际上,我发现最简单的解决方案是通过附加属性:

public class GridViewColumnVisibilityManager
{       
    static void UpdateListView(ListView lv)
    {
        GridView gridview = lv.View as GridView;
        if (gridview == null || gridview.Columns == null) return;
        List<GridViewColumn> toRemove = new List<GridViewColumn>();
        foreach (GridViewColumn gc in gridview.Columns)
        {
            if (GetIsVisible(gc) == false)
            {
                toRemove.Add(gc);
            }
        }
        foreach (GridViewColumn gc in toRemove)
        {
            gridview.Columns.Remove(gc);
        }
    }

    public static bool GetIsVisible(DependencyObject obj)
    {
        return (bool)obj.GetValue(IsVisibleProperty);
    }

    public static void SetIsVisible(DependencyObject obj, bool value)
    {
        obj.SetValue(IsVisibleProperty, value);
    }

    public static readonly DependencyProperty IsVisibleProperty =
        DependencyProperty.RegisterAttached("IsVisible", typeof(bool), typeof(GridViewColumnVisibilityManager), new UIPropertyMetadata(true));


    public static bool GetEnabled(DependencyObject obj)
    {
        return (bool)obj.GetValue(EnabledProperty);
    }

    public static void SetEnabled(DependencyObject obj, bool value)
    {
        obj.SetValue(EnabledProperty, value);
    }

    public static readonly DependencyProperty EnabledProperty =
        DependencyProperty.RegisterAttached("Enabled", typeof(bool), typeof(GridViewColumnVisibilityManager), new UIPropertyMetadata(false,
            new PropertyChangedCallback(OnEnabledChanged)));

        private static void OnEnabledChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
    {
        ListView view = obj as ListView;
        if (view != null)
        {
            bool enabled = (bool)e.NewValue;
            if (enabled)
            {
                view.Loaded += (sender, e2) =>
                {
                    UpdateListView((ListView)sender);
                };
                view.TargetUpdated += (sender, e2) =>
                {
                    UpdateListView((ListView)sender);
                };
                view.DataContextChanged += (sender, e2) =>
                {
                    UpdateListView((ListView)sender);
                };
            }
        }
    }
}

然后,它可以这样使用:

<ListView foo:GridViewColumnVisibilityManager.Enabled="True">
...
<GridViewColumn Header="Status" foo:GridViewColumnVisibilityManager.IsVisible="{Binding ShowStatusColumn}">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate> ...

Answer 2

基于Ben McMillan的回答,但支持动态改变可见属性.我通过删除IsEnabled属性进一步简化了他的解决方案.

public class GridViewColumnVisibilityManager
{
    static Dictionary<GridViewColumn, double> originalColumnWidths = new Dictionary<GridViewColumn, double>();

    public static bool GetIsVisible(DependencyObject obj)
    {
        return (bool)obj.GetValue(IsVisibleProperty);
    }

    public static void SetIsVisible(DependencyObject obj, bool value)
    {
        obj.SetValue(IsVisibleProperty, value);
    }

    public static readonly DependencyProperty IsVisibleProperty =
        DependencyProperty.RegisterAttached("IsVisible", typeof(bool), typeof(GridViewColumnVisibilityManager), new UIPropertyMetadata(true, OnIsVisibleChanged));

    private static void OnIsVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        GridViewColumn gc = d as GridViewColumn;
        if (gc == null)
            return;

        if (GetIsVisible(gc) == false)
        {
            originalColumnWidths[gc] = gc.Width;
            gc.Width = 0;
        }
        else
        {
            if (gc.Width == 0)
                gc.Width = originalColumnWidths[gc];
        }
    }
}

Answer 3

您最好的选择可能是通过继承GridView类,添加所需的列以及显示有意义的属性来显示/隐藏特定列来创建自定义控件.您的自定义GridView类可能如下所示:

using System;
using System.Windows.Controls;

namespace MyProject.CustomControls
{
    public class CustomGridView : GridView
    {
        private GridViewColumn _fixedColumn;
        private GridViewColumn _optionalColumn;

        public CustomGridView()
        {
            this._fixedColumn = new GridViewColumn() { Header = "Fixed Column" };
            this._optionalColumn = new GridViewColumn() { Header = "Optional Column" };

            this.Columns.Add(_fixedColumn);
            this.Columns.Add(_optionalColumn);
        }

        public bool ShowOptionalColumn
        {
            get { return _optionalColumn.Width > 0; }
            set
            {
                // When 'False' hides the entire column
                // otherwise its width will be set to 'Auto'
                _optionalColumn.Width = (!value) ? 0 : Double.NaN;
            }
        }

    }
}

然后,您可以像在此示例中一样从XAML设置该属性:

<Window x:Class="WpfApplication1.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:cc="clr-namespace:MyProject.CustomControls"
        Title="Window1"
        Height="300"
        Width="300">
    <StackPanel>
        <ListView>
            <ListView.View>
                <cc:CustomGridView ShowOptionalColumn="False" />
            </ListView.View>
        </ListView>

        <ListView>
            <ListView.View>
                <cc:CustomGridView ShowOptionalColumn="True" />
            </ListView.View>
        </ListView>
    </StackPanel>
</Window>

或者,您可以使' CustomGridView.ShowOptionalColumn '成为DependencyProperty,以便能够将其用作绑定目标.

Answer 4

我建议在父级上使用自定义属性（或劫持现有属性），然后在 gridviewcolumnheader 上使用自定义样式来引用该祖先属性。像这样：

<Window.Resources>
    <Style TargetType="{x:Type GridViewColumnHeader}">
        <Setter Property="Visibility" Value="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListView}}, Path=Tag}"/>
    </Style>
    <GridView x:Key="myGridView" x:Shared="false">                             
        <GridViewColumn Header="Created" DisplayMemberBinding="{Binding Path=Created}"/>    
    </GridView>
</Window.Resources>
<Grid x:Name="LayoutRoot">
    <StackPanel>
        <ListView x:Name="detailList"   View="{StaticResource myGridView}"/>
        <ListView x:Name="detailListHide" Tag="{x:Static Member=Visibility.Hidden}" View="{StaticResource myGridView}"/>
    </StackPanel>
</Grid>