TreeView 不显示来自 Web 窗体项目中对 OnSelectedNodeChange 的函数调用的已检查节点

Question

我只想显示选中节点的值，并且我有以下相关代码

Default.aspx

 <asp:Literal ID="Message" runat="server"></asp:Literal>
    <asp:Button ID="Button1" runat="server" Text="Button" Width="56px" 
            OnClick="Select_Change" />
      <div>
     
          <asp:TreeView ID="TreeView1" runat="server" 
              ShowCheckBoxes="All"
              OnSelectedNodeChanged="Select_Change"
              >

          </asp:TreeView>
      </div>

Default.aspx.cs

protected void Page_Load(object sender, EventArgs e)
        { 
            //These variables and methods create a hierarchy of the folder structure.
            var latestDirectory = DirectoryList().First().FullName.ToString();
            
            this.directoryFiles = DirSearch(latestDirectory);
            this.directoryArray = dirArray;
            this.directoryString.Text = latestDirectory;

            ListDirectory(TreeView1, latestDirectory);
        }

protected void Select_Change(object sender, EventArgs e)
        {
            string message = "selected nodes \n";
            
            foreach(TreeNode item in TreeView1.CheckedNodes)
            {
                message += item.Text;
            }
            Message.Text = message;
        }

当我单击该按钮时，它只显示通用的“选定节点”，后面什么也没有，即使在选定节点之后也是如此。关于我在这里遗漏的任何想法？

Answer 1

选中的项目，只是一个项目，你要勾选值的集合。

这个：

    For Each tN As TreeNode In TreeView1.CheckedNodes
        Debug.Print("Sel node = " & tN.Value & "," & tN.Text)
    Next

或

    foreach (TreeNode tN in TreeView1.CheckedNodes) 
    {
        Debug.Print("Sel node = " & tN.Value & "," & tN.Text);
        message += tN.Value.ToString() + "->" + tN.Text + "| "; 
    }

那么，您的代码是否正在同时设置值和文本？或者您可能只是在设置 .Value。不清楚电视是如何加载的？

编辑 ======================================= ================ 让我们举一个完整的例子。我们有这个：

        <asp:TreeView ID="TreeView1" runat="server"
            ShowCheckBoxes="All">
        </asp:TreeView>

        <br />
        <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
        <br />
        <asp:TextBox ID="TextBox1" runat="server" Width="347px"></asp:TextBox>

代码：

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            LoadTree();
    }

    void LoadTree()
    {
        for (int i = 1; i <= 5; i++)
            TreeView1.Nodes.Add(new TreeNode("Tx " + i, "Vx" + i));
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        string sChoices = "";
        foreach (TreeNode tN in TreeView1.CheckedNodes)
            sChoices += "(" + tN.Value + "," + tN.Text + ") ";

        TextBox1.Text = sChoices;
    }

所以，我们运行并检查前两个，这样说：

TreeView 不显示来自 Web 窗体项目中对 OnSelectedNodeChange 的函数调用的已检查节点

TreeView not showing checked nodes from function call to OnSelectedNodeChange in a Web Forms projet

c#

asp.net

webforms