c# – WPF TreeView刷新

我有一个问题.我在我的 WPF项目中使用TreeView来可视化我的 XML数据.问题是,当我编辑我的XmlDocument时,它不会在TreeView中刷新.但是我注意到当我检查Selectednode时,它是我的编辑和XmlNode.所以我的“编辑”方法工作正常,但我的树的视觉刷新只有一个问题. .Refresh()或.Items.Refresh()也不起作用.

这是我树的模板：

<DataTemplate x:Key="AttributeTemplate">
    <StackPanel Orientation="Horizontal"
            Margin="3,0"
            HorizontalAlignment="Center">
        <TextBlock Text="{Binding Path=Name}"
             Foreground="{StaticResource xmAttributeBrush}" FontFamily="Consolas" FontSize="8pt" />
        <TextBlock Text="=&quot;"
             Foreground="{StaticResource xmlMarkBrush}" FontFamily="Consolas" FontSize="8pt" />
        <TextBlock Text="{Binding Path=Value,Mode=TwoWay}"
             Foreground="{StaticResource xmlValueBrush}" FontFamily="Consolas" FontSize="8pt" />
        <TextBlock Text="&quot;"
             Foreground="{StaticResource xmlMarkBrush}" FontFamily="Consolas" FontSize="8pt" />
    </StackPanel>
</DataTemplate>

<HierarchicalDataTemplate x:Key="NodeTemplate">
    <StackPanel Orientation="Horizontal" Focusable="False">
        <TextBlock x:Name="tbName" Text="?" FontFamily="Consolas" FontSize="8pt" />
        <ItemsControl
            ItemTemplate="{StaticResource AttributeTemplate}"
            ItemsSource="{Binding Path=Attributes}"
            HorizontalAlignment="Center">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <StackPanel Orientation="Horizontal"/>
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>
    </StackPanel>
    <HierarchicalDataTemplate.ItemsSource>
        <Binding XPath="*" />
    </HierarchicalDataTemplate.ItemsSource>
    <HierarchicalDataTemplate.Triggers>
        <DataTrigger Binding="{Binding Path=NodeType}" Value="Text">
            <Setter TargetName="tbName" Property="Text" Value="{Binding Path=Value,Mode=TwoWay}"/>
        </DataTrigger>
        <DataTrigger Binding="{Binding Path=NodeType}" Value="Element">
            <Setter TargetName="tbName" Property="Text" Value="{Binding Path=Name}"/>
        </DataTrigger>
    </HierarchicalDataTemplate.Triggers>
</HierarchicalDataTemplate>

<Style x:Key="TreeViewAllExpandedStyle"  targettype="{x:Type TreeView}">
    <Style.Resources>
        <Style targettype="TreeViewItem">
            <Setter Property="IsExpanded" Value="True" />
        </Style>
    </Style.Resources>
</Style>

<Style x:Key="TreeViewAllCollapsedStyle" targettype="{x:Type TreeView}">
    <Style.Resources>
        <Style targettype="TreeViewItem">
            <Setter Property="IsExpanded" Value="False" />
        </Style>
    </Style.Resources>
</Style>

这是Window.Resources：

<Window.Resources>
    <XmlDataProvider x:Key="XmlData" />
</Window.Resources>

这是我的树：

<TreeView x:Name="XmlTree" Grid.Row="1"
      ItemsSource="{Binding Source={StaticResource XmlData},XPath=.,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
      ItemTemplate="{StaticResource NodeTemplate}"
      selecteditemchanged="XmlTree_selecteditemchanged" />

这是我的代码背后：

private XmlDocument _xml;
private XmlElement _selectedElement;
private XmlDataProvider _xmlDataProvider;

private void MainWindow_Load(object sender,EventArgs e)
{
    XmlTree.Style = (Style)FindResource("TreeViewAllExpandedStyle");
    _xmlDataProvider = FindResource("XmlData") as XmlDataProvider;
}

private void OpenXmlFile(string filePath)
{
    _xml = new XmlDocument();
    _xml.Load(filePath);

    _xmlDataProvider.Document = _xml;
}

private void SaveChangesButton_Click(object sender,EventArgs e)
{
    Dictionary<string,string> newAttributes = GetChangedAttributes();
    foreach (keyvaluePair<string,string> pair in newAttributes)
    {
        _selectedElement.SetAttribute(pair.Key,pair.Value);
    }

    RefreshViews();
}

private void RefreshViews()
{
    // Now I don't kNow what to do here,any Refresh doesn't work:S
}

第二件事是,如何清除我的树以便能够再次使用它来获取另一个数据(我在尝试XmlTree.Items.Clear()时遇到了NullReferenceException;

解决方法

经过几个小时终于找到了解决方案！

private void RefreshViews()
{
    XmlEditor.Clear();
    XmlEditor.Text = IndentXml();

    UnselectSelectedItem();

    XmlTree.Items.Refresh();
    XmlTree.UpdateLayout();
}

private void UnselectSelectedItem()
{
    if (XmlTree.SelectedItem != null)
    {
        var container = FindTreeViewSelectedItemContainer(XmlTree,XmlTree.SelectedItem);
        if (container != null)
        {
            container.IsSelected = false;
        }
    }
}

private static TreeViewItem FindTreeViewSelectedItemContainer(ItemsControl root,object selection)
{
    var item = root.ItemContainerGenerator.ContainerFromItem(selection) as TreeViewItem;
    if (item == null)
    {
        foreach (var subItem in root.Items)
        {
            item = FindTreeViewSelectedItemContainer((TreeViewItem)root.ItemContainerGenerator.ContainerFromItem(subItem),selection);
            if (item != null)
            {
                break;
            }
        }
    }

    return item;
}

原文地址：https://www.jb51.cc/csharp/93659.html