问无法让Silverlight HierarchicalDataTemplate显示IsolatedStorage文件夹
EN

Stack Overflow用户

提问于 2013-04-09 15:28:47

回答 2查看 243关注 0票数 0

这是我第一次尝试层次化数据，我遇到了一点问题。

在Silverlight4中，我正在尝试获取要在TreeView中显示的独立存储文件夹的列表。根本不显示任何内容。我的树状视图是完全空白的。我遗漏了什么？我正在获取数据，它是正确的。

任何帮助都将不胜感激。

XAML

 <sdk:TreeView x:Name="FolderTreeView" Grid.Column="0" Margin="0,0,3,0" ItemsSource="{Binding _Folders}">
            <sdk:TreeView.ItemTemplate>
                <sdk:HierarchicalDataTemplate ItemsSource="{Binding Path=Folders}">
                    <TextBlock Margin="0" Text="{Binding Name, Mode=OneWay}"/>
                </sdk:HierarchicalDataTemplate>
            </sdk:TreeView.ItemTemplate>
        </sdk:TreeView>

政务司司长

internal class Folder
{
    public Folder() { Folders = new List<Folder>(); }
    public string Name { get; set; }
    public List<Folder> Folders { get; set; }
}

private List<Folder>  _Folders = new List<Folder>();
public OpenFileDialog()
{
    InitializeComponent();

    ifs = IsolatedStorageFile.GetUserStoreForApplication();
    var folder = new Folder
    {
        Name = "Root",
        Folders = (from c in ifs.GetDirectoryNames()
            select new Folder
            {
                Name = c,
                Folders = LoadFolders(c)
            }).ToList()
    };
    _Folders.Add(folder);
    FolderTreeView.DataContext = new { _Folders };
}

private List<Folder>LoadFolders(string folderName)
{
    if(folderName == null)
        return null;
    return (from c in ifs.GetDirectoryNames(folderName + "\\*.*")
        select new Folder
        {
            Name = c,
            Folders = LoadFolders(c)
        }).ToList();
}

谢谢

silverlight-4.0

treeview

hierarchicaldatatemplate

回答 2

Stack Overflow用户

发布于 2013-04-09 15:56:19

几件事

<sdk:TreeView x:Name="FolderTreeView" Grid.Column="0" Margin="0,0,3,0" 
              ItemsSource="{Binding _Folders}">

您不能绑定到私有成员。

您需要使用ObservableCollections而不是List。绑定管理器有效地侦听由ObservableCollection触发的CollectionChanged事件，并通知绑定的控件。

您需要实现INotifyPropertyChanged并在您的属性设置器中引发PropertyChanged通知。

最后，您是否设置了树视图的DataContext？

另外，在输出调试窗口中查找与绑定相关的错误。

编辑，ok尝试：

FolderTreeView.DataContext =  this;

并将_Folders包装在属性中

public ObservableCollection <Folder> Folders
    {
    get
       {
       return _Folders;
       }
    set
       {
       _Folders = value;
       OnPropertyChanged("Folders");
       }
   }

将绑定更改为

<sdk:TreeView x:Name="FolderTreeView" Grid.Column="0" Margin="0,0,3,0" 
              ItemsSource="{Binding Folders}">

我改变了很多，

    public class Folder : INotifyPropertyChanged
        {

        public Folder(string folderName) 
            {
            Name = folderName;
            Folders = new ObservableCollection<Folder>();
            var _ifs = IsolatedStorageFile.GetUserStoreForApplication();

            if (folderName != null)
                {
                Folders = new ObservableCollection<Folder>(
                        (from c in _ifs.GetDirectoryNames(folderName + "\\*.*")
                         select new Folder(folderName + "\\" + c)
                   ));
                }
            else
                {
                Folders = new ObservableCollection<Folder>(
                       (from c in _ifs.GetDirectoryNames()
                        select new Folder(folderName + "\\" + c)
                  ));
                }
            }


        public string Name { get; set; }

        private ObservableCollection<Folder> _Folders; 
        public ObservableCollection<Folder> Folders 
            {
            get { return _Folders; }
            set { _Folders = value; OnPropertyChanged("RootFolder"); }
            }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;
        protected void OnPropertyChanged(string propertyName)
            {
            if (PropertyChanged != null)
                {
                PropertyChanged(this,
                    new PropertyChangedEventArgs(propertyName));
                }
            }
        #endregion
    }



public partial class OpenFileDialog : UserControl
    {      
    public OpenFileDialog()
        {
        InitializeComponent();

        RootFolder = new Folder (null);
        RootFolders = new ObservableCollection<Folder>();
        RootFolders.Add(RootFolder);

        FolderTreeView.DataContext = this;
        }


    private Folder _RootFolder;
    public Folder RootFolder
        {
        get { return _RootFolder; }
        set { _RootFolder = value; }
        }


    private ObservableCollection<Folder> _RootFolders;
    public ObservableCollection<Folder> RootFolders
        {
        get { return _RootFolders; }
        set { _RootFolders = value; }
        }

    }

xaml

 <sdk:TreeView x:Name="FolderTreeView"  Margin="0,0,3,0" ItemsSource="{Binding RootFolders}">
    <sdk:TreeView.ItemTemplate>
        <sdk:HierarchicalDataTemplate ItemsSource="{Binding Path=Folders}">
            <StackPanel>
            <TextBlock Margin="0" Text="{Binding Name, Mode=OneWay}"/>
            </StackPanel>
        </sdk:HierarchicalDataTemplate>
    </sdk:TreeView.ItemTemplate>
</sdk:TreeView>