来自 DataSet 的分层 TreeView

Question

我是 WPF 新手，不知道如何将该数据集绑定到树视图

Dim dtHDD As New DataTable("Disks")
dtHDD.Columns.Add("ID")
dtHDD.Columns.Add("DiskName")

dtHDD.Rows.Add(1, "Disc1")
dtHDD.Rows.Add(2, "Disc2")

Dim dtFolders As New DataTable("Folders")
dtFolders.Columns.Add("ID")
dtFolders.Columns.Add("DiskID")
dtFolders.Columns.Add("FolderID")
dtFolders.Columns.Add("FolderName")

dtFolders.Rows.Add(1, 2, DBNull.Value, "Music")
dtFolders.Rows.Add(2, 1, DBNull.Value, "Documents")
dtFolders.Rows.Add(3, 1, 2, "Scatches")
dtFolders.Rows.Add(4, 1, 3, "Images")
dtFolders.Rows.Add(5, 1, 3, "Folder1")
dtFolders.Rows.Add(6, 1, 2, "Bin")
dtFolders.Rows.Add(7, 2, DBNull.Value, "Moves")
dtFolders.Rows.Add(8, 1, 5, "Another one")


Dim dtFiles As New DataTable("Files")
dtFiles.Columns.Add("ID")
dtFiles.Columns.Add("FolderID")
dtFiles.Columns.Add("FileName")

dtFiles.Rows.Add(1, 8, "file1")
dtFiles.Rows.Add(2, 2, "file2")
dtFiles.Rows.Add(3, 3, "file3")
dtFiles.Rows.Add(4, 2, "file4")
dtFiles.Rows.Add(5, 5, "file5")
dtFiles.Rows.Add(6, 5, "file6")
dtFiles.Rows.Add(7, 8, "file7")
dtFiles.Rows.Add(8, 8, "file8")
dtFiles.Rows.Add(9, 1, "file9")

Dim ds As New DataSet
ds.Tables.Add(dtHDD)
ds.Tables.Add(dtFolders)
ds.Tables.Add(dtFiles)
ds.Relations.Add("DiskFolder", ds.Tables("Disks").Columns("ID"), ds.Tables("Folders").Columns("DiskID"))
ds.Relations.Add("FolderFolder", ds.Tables("Folders").Columns("ID"), ds.Tables("Folders").Columns("FolderID"))
ds.Relations.Add("FolderFile", ds.Tables("Folders").Columns("ID"), ds.Tables("Files").Columns("FolderID"))

treeTest.ItemsSource = ds.Tables("Disks").DefaultView

所以每个磁盘只能包含文件夹。 每个文件夹都可以包含文件和文件夹。 我做了以下标记

<TreeView x:Name="treeTest" Margin="380,0,0,0">
    <TreeView.ItemTemplate>
        <HierarchicalDataTemplate ItemsSource="{Binding DiskFolder}">
            <TextBlock Text="{Binding DiskName}"/>
            <HierarchicalDataTemplate.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding FolderName}" />
                </DataTemplate>
            </HierarchicalDataTemplate.ItemTemplate>
        </HierarchicalDataTemplate>
    </TreeView.ItemTemplate>
</TreeView>

但我不知道如何为文件夹表设置 RowFilter 规则以及如何在该树视图中添加文件。

Answer 1

您可以使用 DataTemplateSelector 根据父表的名称选择适当的模板：

Public Class TemplateSelector
    Inherits DataTemplateSelector

    Public Property DiskTemplate As DataTemplate
    Public Property FolderTemplate As DataTemplate
    Public Property FileTemplate As DataTemplate

    Public Overrides Function SelectTemplate(item As Object, container As DependencyObject) As DataTemplate

        Dim drv = CType(item, System.Data.DataRowView)
        Select Case drv.DataView.Table.TableName
            Case "Disks"
                Return DiskTemplate
            Case "Folders"
                Return FolderTemplate
            Case "Files"
                Return FileTemplate
        End Select

        Return Nothing

    End Function

End Class

用法：

<Window x:Class="Window1"
        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:WpfApplication1"
        mc:Ignorable="d"
        Title="Window1" Height="300" Width="300">
    <Window.Resources>
        <HierarchicalDataTemplate x:Key="diskTemplate" ItemsSource="{Binding DiskFolder}">
            <TextBlock Text="{Binding DiskName}"/>
        </HierarchicalDataTemplate>

        <HierarchicalDataTemplate x:Key="folderTemplate" ItemsSource="{Binding FolderFile}">
            <TextBlock Text="{Binding FolderName}"/>
        </HierarchicalDataTemplate>

        <DataTemplate x:Key="fileTemplate">
            <TextBlock Text="{Binding FileName}"/>
        </DataTemplate>

        <local:TemplateSelector x:Key="TemplateSelector"
                                DiskTemplate="{StaticResource diskTemplate}" 
                                FolderTemplate="{StaticResource folderTemplate}"
                                FileTemplate="{StaticResource fileTemplate}"/>
    </Window.Resources>
    <StackPanel>
        <TreeView x:Name="treeTest" ItemTemplateSelector="{StaticResource TemplateSelector}" />
    </StackPanel>
</Window>

Answer 2

我就是这样做的

<HierarchicalDataTemplate x:Key="folderTemplate" ItemsSource="{Binding FolderFolder}">
    <TextBlock Text="{Binding FolderName}"/>
</HierarchicalDataTemplate>

MyWindow

我想左边为行添加一个过滤器

RowFilter = "FolderID is null"

但是怎么不明白...

Answer 3

最后我想看看那个结构

<disc Name="Disc1">
    <folder Name="Documents">
        <folder Name="Scatches">
            <folder Name="Images"/>
            <folder Name="Folder1">
                <folder Name="Another one">
                    <file Name="file1"/>
                    <file Name="file7"/>
                    <file Name="file8"/>
                </folder>
                <file Name="file5"/>
                <file Name="file6"/>
            </folder>
            <file Name="file3"/>
        </folder>
        <folder Name="Bin"/>
        <file Name="file2"/>
        <file Name="file4"/>
    </folder>
</disc>
<disc Name="Disc2">
    <folder Name="Music">
        <file Name="file9"/>
    </folder>
    <folder Name="Moves" />
</disc>