c# WPF 过滤控件列表

Question

有没有人试过过滤控件列表？我有一些简单的示例代码可以说明我似乎无法解决的问题。过滤文本列表时我没有问题，但是当我将列表转换为可观察的控件列表时，任何过滤器我运行都会影响其他过滤器。这是一些有效的示例代码

代码：

public partial class MainWindow : Window
{
    public ObservableCollection<string> testOC { get; set; }
    public MainWindow()
    {
        InitializeComponent();

        testOC = new ObservableCollection<string>();

        for (int i = 0; i < 20; i++)
        {
            testOC.Add("Test Stuff " + i);
        }

        ListCollectionView view1 = new ListCollectionView(testOC);
        ListCollectionView view2 = new ListCollectionView(testOC);
        view1.Filter = Filter1;
        view2.Filter = Filter2;
        leftGrid.ItemsSource = testOC;
        MiddleGrid.ItemsSource = view1;
        rightGrid.ItemsSource = view2;
    }

    private bool Filter1(object test)
    {
        try
        {
            var testStuff = test as string;

            if (testStuff.Contains("1"))
            {
                return true;
            }
            return false;
        }
        catch (Exception)
        {
            throw;
        }
    }
    private bool Filter2(object test)
    {
        try
        {
            var testStuff = test as string;

            if (testStuff.Contains("2"))
            {
                return true;
            }
            return false;
        }
        catch (Exception)
        {
            throw;
        }
    }
}

XML:

<Window x:Class="testTheFilter.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:testTheFilter"
    mc:Ignorable="d"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="150"/>
        <ColumnDefinition Width="150"/>
        <ColumnDefinition Width="150"/>
    </Grid.ColumnDefinitions>

    <Grid.RowDefinitions>
        <RowDefinition Height="25"/>
        <RowDefinition Height="775"/>
    </Grid.RowDefinitions>
    <ItemsControl Name="leftGrid" Grid.Column="0" Grid.RowSpan="2"/>
    <ItemsControl Name="MiddleGrid" Grid.Column="1" Grid.RowSpan="2"/>
    <ItemsControl Name="rightGrid" Grid.Column="2" Grid.RowSpan="2"/>
</Grid>

代码运行截图：

这按预期工作，您得到三个列表，第一个列表包含所有字符串，第二个列表仅包含带 1 的字符串，第三个列表仅包含带 2 的字符串。

现在，如果我采用完全相同的代码并将其更改为控件列表，它就会变得不稳定

这是代码部分：

public partial class MainWindow : Window
{
    public ObservableCollection<Button> testOC { get; set; }
    public MainWindow()
    {
        InitializeComponent();

        testOC = new ObservableCollection<Button>();

        for (int i = 0; i < 20; i++)
        {
            Button btn = new Button();
            btn.Content = "Test Stuff " + i;
            testOC.Add(btn);
        }

        ListCollectionView view1 = new ListCollectionView(testOC);
        ListCollectionView view2 = new ListCollectionView(testOC);
        view1.Filter = Filter1;
        view2.Filter = Filter2;
        leftGrid.ItemsSource = testOC;
        MiddleGrid.ItemsSource = view1;
        rightGrid.ItemsSource = view2;
    }

    private bool Filter1(object test)
    {
        try
        {
            var testStuff = test as Button;

            if (testStuff.Content.ToString().Contains("1"))
            {
                return true;
            }
            return false;
        }
        catch (Exception)
        {
            throw;
        }
    }
    private bool Filter2(object test)
    {
        try
        {
            var testStuff = test as Button;

            if (testStuff.Content.ToString().Contains("2"))
            {
                return true;
            }
            return false;
        }
        catch (Exception)
        {
            throw;
        }
    }
}

下面是代码无法运行的屏幕截图：

有没有人以前见过这种行为，有没有人知道如何解决这个问题？我花了几个小时研究这个问题，但似乎找不到解决办法。

提前致谢

Answer 1

既然不能同时将一个视觉元素（按钮）添加到不同的parents，为什么不使用DataTemplates呢？如果您保留第一个示例中的代码，只需编辑 XAML 就可以开始了：

<Grid>
    <Grid.Resources>
        <DataTemplate x:Key="itemTemplate">
            <Button>
                <ContentPresenter Content="{Binding}" />
            </Button>
        </DataTemplate>
    </Grid.Resources>

    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="150"/>
        <ColumnDefinition Width="150"/>
        <ColumnDefinition Width="150"/>
    </Grid.ColumnDefinitions>

    <Grid.RowDefinitions>
        <RowDefinition Height="25"/>
        <RowDefinition Height="775"/>
    </Grid.RowDefinitions>
    <ItemsControl Name="leftGrid" Grid.Column="0" Grid.RowSpan="2" ItemTemplate="{StaticResource itemTemplate}" />
    <ItemsControl Name="MiddleGrid" Grid.Column="1" Grid.RowSpan="2" ItemTemplate="{StaticResource itemTemplate}" />
    <ItemsControl Name="rightGrid" Grid.Column="2" Grid.RowSpan="2" ItemTemplate="{StaticResource itemTemplate}" />
</Grid>

Answer 2

像一样，一个视觉元素不能是多个父元素的子元素。按钮是一个视觉元素 - 字符串不是。如果您将代码更改为此，您会得到不满意的结果：

    public ObservableCollection<Button> testOC { get; set; }
    public ObservableCollection<Button> testOC1 { get; set; }
    public ObservableCollection<Button> testOC2 { get; set; }

    public MainWindow()
    {
        InitializeComponent();

        testOC = new ObservableCollection<Button>();
        testOC1 = new ObservableCollection<Button>();
        testOC2 = new ObservableCollection<Button>();

        for (int i = 0; i < 20; i++)
        {
            var content = "Test Stuff " + i;

            Button btn = new Button();
            btn.Content = content;
            testOC.Add(btn);

            Button btn1 = new Button();
            btn1.Content = content;
            testOC1.Add(btn1);

            Button btn2 = new Button();
            btn2.Content = content;
            testOC2.Add(btn2);
        }

        ListCollectionView view1 = new ListCollectionView(testOC1);
        ListCollectionView view2 = new ListCollectionView(testOC2);
        view1.Filter = Filter1;
        view2.Filter = Filter2;
        leftGrid.ItemsSource = testOC;
        MiddleGrid.ItemsSource = view1;
        rightGrid.ItemsSource = view2;
    }

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