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TreeListVirtualModeNodeCreatingEventArgs.SetNodeValue(String, Object) Method

Assigns a value to the specified cell.

Namespace: DevExpress.Web.ASPxTreeList

Assembly: DevExpress.Web.ASPxTreeList.v24.1.dll

NuGet Package: DevExpress.Web

Declaration

public void SetNodeValue(
    string fieldName,
    object value
)

Parameters

Name Type Description
fieldName String

A String value that specifies the field name which identifies the required cell.

value Object

An object that represents the value to be assigned.

Example

In this example, the ASPxTreeList uses the Virtual data binding method to display the file/folder tree. In this mode, a tree is created on demand.

The image below shows the result.

exVirtualMode

using System.IO;
using System.Collections.Generic;
using DevExpress.Web.ASPxTreeList;

protected void ASPxTreeList1_VirtualModeCreateChildren(object sender,
TreeListVirtualModeCreateChildrenEventArgs e) {
    string path = e.NodeObject == null ? Page.MapPath("~/") : e.NodeObject.ToString();

    List<string> children = new List<string>();
    if (Directory.Exists(path)) {
        foreach (string name in Directory.GetDirectories(path)) {
            if (!IsSystemName(name))
                children.Add(name);
        }
        foreach (string name in Directory.GetFiles(path))
            if (!IsSystemName(name))
                children.Add(name);
    }
    e.Children = children;
}
protected void ASPxTreeList1_VirtualModeNodeCreating(object sender,
TreeListVirtualModeNodeCreatingEventArgs e) {
    string path = e.NodeObject.ToString();

    e.NodeKeyValue = GetNodeGuid(path);
    e.IsLeaf = !Directory.Exists(path);
    e.SetNodeValue("FileName", PopFileName(path));
}

// Helpers

Guid GetNodeGuid(string path) {
    if (!Map.ContainsKey(path))
        Map[path] = Guid.NewGuid();
    return Map[path];
}
Dictionary<string, Guid> Map {
    get {
        const string key = "DX_PATH_GUID_MAP";
        if (Session[key] == null)
            Session[key] = new Dictionary<string, Guid>();
        return Session[key] as Dictionary<string, Guid>;
    }
}
string PopFileName(string path) {
    return path.Substring(1 + path.LastIndexOf("\\"));
}
bool IsSystemName(string name) {
    name = PopFileName(name).ToLower();
    return name.StartsWith("app_") || name == "bin"
        || name.EndsWith(".aspx.cs") || name.EndsWith(".aspx.vb");
}

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the SetNodeValue(String, Object) method.

Note

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See Also