Question

在MSDN中写了关于TreeNode：

“默认情况下，节点处于选择模式。”

“要将节点置于选择模式，请将节点的NavigateUrl属性设置为空字符串。”

“当节点处于选择模式时，使用SelectAction属性指定选择节点时引发的事件。”

“设置TreeNodeSelectAction值TreeNodeSelectAction.Select在选择节点时引发SelectedNodeChanged事件。”

这是问题，可能是控件中的错误：

当我将TreeNode对象PopulateOnDemand值设置为true并在该节点上调用Collapse（）函数时。然后，除了SelectedNodeChanged事件之外，还会引发TreeNodeExpanded事件。这与MSDN中所写的内容相矛盾。根据MSDN，只有在TreeNodeSelectAction属性设置为时才会发生这种情况 TreeNodeSelectAction.SelectExpand value。

有些人知道原因吗？

以下是代码：

<asp:TreeView ID="TreeView1" runat="server" AutoGenerateDataBindings="False" 
                    onselectednodechanged="TreeView1_SelectedNodeChanged" 
                    ontreenodepopulate="TreeView1_TreeNodePopulate">
                </asp:TreeView>



protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        string path = Server.MapPath(".");
        PopulateTopNodes(path);

    }
}

//MSDN : Occurs when a node with its PopulateOnDemand property set to true is expanded in   //the  TreeView control.
protected void TreeView1_TreeNodePopulate(object sender, TreeNodeEventArgs e)
{
   LoadChildNode(e.Node);      
}

private void PopulateTopNodes(string pathToRootFolder)
{
    DirectoryInfo dirInfo = new DirectoryInfo(pathToRootFolder);
    DirectoryInfo[] dirs = dirInfo.GetDirectories();
    foreach (DirectoryInfo dir in dirs)
    {
        string relativePath = (dir.FullName).Replace(pathToRootFolderPrefix, "");
        TreeNode folderNode = new TreeNode(dir.Name, relativePath);

        if (dir.GetDirectories().Length > 0)
        {
            folderNode.PopulateOnDemand = true;
            folderNode.Collapse();

        }
        folderNode.NavigateUrl = "";
        folderNode.SelectAction = TreeNodeSelectAction.Select;
        TreeView1.Nodes.Add(folderNode);
    }
}

 private void LoadChildNode(TreeNode treeNode)
{


    string d = treeNode.NavigateUrl;
    string action = treeNode.SelectAction.ToString(); 


    string fullPath = Path.Combine(pathToRootFolderPrefix, treeNode.Value);
    DirectoryInfo dirInfo = new DirectoryInfo(fullPath);


    DirectoryInfo[] dirs = dirInfo.GetDirectories();
    foreach (DirectoryInfo dir in dirs)
    {


        string relativePath = (dir.FullName).Replace(pathToRootFolderPrefix, "");
        TreeNode folderNode = new TreeNode(dir.Name, relativePath);

        if(dir.GetDirectories().Length>0){
            folderNode.PopulateOnDemand = true;
            folderNode.Collapse();

        }
        folderNode.NavigateUrl = "";
        folderNode.SelectAction = TreeNodeSelectAction.Select;
        treeNode.ChildNodes.Add(folderNode);
    }
}

//MSDN:Occurs when a node is selected in the TreeView control.
protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
{


}

由于

Answer 1

我不知道ASP.Net，但只是阅读你的代码，你将它设置为SelectExpand，但在上面的评论中，听起来你认为你将它设置为选择（或者这只是一个错字示例代码？）。在您的示例中的两种方法中，它都写为：

folderNode.SelectAction = TreeNodeSelectAction.SelectExpand;

TreeView控制意外事件行为

1 个答案: