如何选择使用TreeViewItem填充的WPF TreeViewItem？

Question

我有一个WPF TreeView，它是在运行时从一个XML文件中填充的。单击一个按钮，就会出现一个FileDialog框，然后选择一个XML文件。然后将XML文件加载到TreeView中。我使用了一个XmlDataProvider和一些HierarchicalDataTemplate来加载XML。

我已经在TreeView中添加了一个操作处理程序，但是当我选择该TreeView的一个项时，我找不到该项的任何引用。我只找到第一个元素的引用。

我怎样才能解决这个问题？

XAML是：

<Window x:Class="Demo2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="600" Width="800">
<Window.Resources>
    <XmlDataProvider x:Key="MEIInformation" XPath="/MEI" />
    <HierarchicalDataTemplate DataType="Case" ItemsSource="{Binding}">
        <TextBlock Text="{Binding XPath=@Name}"></TextBlock>            
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate DataType="Phase" ItemsSource="{Binding}">
        <TextBlock Text="{Binding XPath=@Name}"></TextBlock>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate DataType="Trigger" ItemsSource="{Binding}">
        <TextBlock Text="{Binding XPath=@Name}"></TextBlock>
    </HierarchicalDataTemplate>
</Window.Resources>  
<Grid>
    <ToolBarTray>
        <ToolBar>                
            <Button ToolTip="Open Test Suite" Click="OpenTestSuite">
                <Image Source="Icons/open.png"></Image>
            </Button>                
        </ToolBar>
    </ToolBarTray>
    <TreeView x:Name="trv" FontSize="14" Height="518" HorizontalAlignment="Left" Margin="6,31,0,0"  VerticalAlignment="Top" Width="431">
        <TreeViewItem ItemsSource="{Binding Source={StaticResource MEIInformation}, XPath=*}" Header="Suites"></TreeViewItem>
    </TreeView>                           
</Grid>
</Window>

最简单的代码是：

public partial class MainWindow : Window
{     
    public MainWindow()
    {
        InitializeComponent();     
        this.trv.MouseRightButtonUp+=new MouseButtonEventHandler(DoSomething);      
    }    

    private void OpenTestSuite(object sender, RoutedEventArgs e)
    {
        XmlDocument xmlDocument = new XmlDocument();
        OpenFileDialog open = new OpenFileDialog();
        open.Filter = "XML Files (*.xml)|*.xml";
        if (open.ShowDialog() == true)
        {
            xmlDocument.Load(open.FileName);
            XmlDataProvider dataProvider = this.FindResource("MEIInformation") as XmlDataProvider;
            dataProvider.Document = xmlDocument;         
        }
    }        

    private void DoSomething(object sender, MouseEventArgs e)
    {
        MessageBox.Show("Do Something in TreeView!");
        TreeViewItem childItem = e.Source as TreeViewItem;
        if (childItem != null)
        {
            MessageBox.Show(childItem.Header.ToString()); // or MessageBox.Show(childItem.toString);
            childItem.IsSelected = true;
        }
        else
            MessageBox.Show("No Selected Item!");                    
    }                
}

XML

<?xml version="1.0" encoding="ISO-8859-1"?>
<MEI>
    <Case Name="Jean Price">
        <Phase Name="January">
            <Trigger Name="Order # JAN001"></Trigger>
            <Trigger Name="Order # JAN002"></Trigger>
        </Phase>
        <Phase Name="February">
            <Trigger Name="Order # FEB001"></Trigger>
        </Phase>
    </Case>
    <Case Name="John P Grant">
        <Phase Name="April">
            <Trigger Name="Order # APR001"></Trigger>
    <!-- ... -->
</MEI>

我只想有一个该项目的参考，以便我可以添加新的项目后的项目。

@Mart我改变了xaml上的treeview，就像这样.(加上SelectedItemChanged=“DoSomething”)

<TreeView SelectedItemChanged="DoSomething"....../>    

c#代码现在是..。

private void DoSomething(object sender, EventArgs e)
        {
            MessageBox.Show("Do Something in TreeView!");           

            TreeViewItem childItem = sender as TreeViewItem;                        
            if (childItem != null)
            {
                MessageBox.Show(childItem.Header.ToString());
                childItem.IsSelected = true;
                MessageBox.Show("It Works!");
            }
            else
                MessageBox.Show("No Selected Item!");                    
        }     

但一点运气也没有。我还不明白你的UIElement建议.

Answer 1

这就是我找到的获取selectedTreeViewItem值的方法，我是从xmlElement获得的。

考虑到这个xaml代码：

<i>
<Window.Resources>
    <HierarchicalDataTemplate DataType="Filial"
                              ItemsSource="{Binding XPath=./*}">
        <StackPanel Orientation="Horizontal">
            <Image Source="/WpfClient;component/Images/image4.png"
                   Height="20"></Image>
            <TextBlock Margin="5,0,0,0"
                       Text="{Binding XPath=@name}"
                       FontSize="18"
                       FontFamily="BankGothic Md BT"
                       Foreground="#FF355CE5"/>
        </StackPanel>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate DataType="Setor"
                              ItemsSource="{Binding XPath=./*}">
        <StackPanel Orientation="Horizontal">
            <TextBlock Margin="5,0,0,0"
                       Text="{Binding XPath=@name}"
                       FontWeight="Bold" />
        </StackPanel>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate DataType="User">
        <StackPanel Orientation="Horizontal">
            <Image Source="{Binding XPath=@source}"
                   Height="15"></Image>
                <TextBlock Margin="5,0,0,0"
                       Text="{Binding XPath=@name}"
                       FontStyle="Italic" />
        </StackPanel>
    </HierarchicalDataTemplate>
    <XmlDataProvider x:Key="xmlDP"
                     Source="Contatos.xml"
                     XPath="/Contatos/Filial"></XmlDataProvider>
</Window.Resources>
<Grid Width="Auto"
      Height="Auto">
    <TreeView Name="tv"
              ItemsSource="{Binding }"
              DataContext="{StaticResource xmlDP}"
              Margin="0,0,0,0"
              TreeViewItem.Selected="tv_Selected">
        <TreeView.ItemContainerStyle>
            <Style TargetType="TreeViewItem">
                <Setter Property="TreeViewItem.IsExpanded"
                        Value="True" />
            </Style>
        </TreeView.ItemContainerStyle>
    </TreeView>
</Grid>
</i> </pre>

而这个c#代码背后：

private void tv_Selected(object sender, RoutedEventArgs e)
    {
        System.Xml.XmlElement xmlElement= (XmlElement)tv.SelectedItem;

        string mySelectedValue = xmlElement.Attributes[0].Value.ToString();
        MessageBox.Show(mySelectedValue , "SelectedTreeValue", MessageBoxButton.OK, MessageBoxImage.Information);
    }
    </i>

这是xml文件：

<i>
<?xml version="1.0" encoding="utf-8" ?>
  <Contatos>
    <Filial name="Firm">
      <Setor name="Sector 1">
        <User name="user1" source="/WpfClient;component/Images/user.png"></User>
        <User name="user2" source="/WpfClient;component/Images/user.png"></User>
        <User name="user3" source="/WpfClient;component/Images/admin.png"></User>
      </Setor>
     <Setor name="Sector40">
        <User name="user43" source="/WpfClient;component/Images/admin.png"></User>
        <User name="user44" source="/WpfClient;component/Images/user.png"></User>
        <User name="user45" source="/WpfClient;component/Images/user.png"></User>
        <User name="user46" source="/WpfClient;component/Images/user.png"></User>
     </Setor>
   </Filial>
</Contatos>
</i>

Answer 2

我看不出是什么激发了您的DoSomething处理程序，我猜它是对Click事件的响应。

如果是单击项目模板的元素，则可能无法获得正确的发件人参数。

您可以将发送方强制转换为UIElement，然后访问它的DataContext，这应该是您的XML元素之一。

另一种方法是对treeview的SelectionChanged事件作出反应，这将在事件参数中为您提供treview项。