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How to: Validate Nodes (Server-Side)

This example demonstrates how to check the validity of data entered by end-users into a node. Validation is implemented within the ASPxTreeList.NodeValidating event handler. In this sample, validation fails in the cases listed below:

  • the department isn’t specified;
  • the budget is negative.

The image below shows the result:


protected void ASPxTreeList1_NodeValidating(object sender, TreeListNodeValidationEventArgs e) {
    if ((int)e.NewValues["Budget"] < 0)
        e.Errors["Budget"] = "Negative values aren't allowed";
    if (e.NewValues["Department"] == null)
        e.Errors["Department"] = "Required field";
    if (e.Errors.Count != 0)
        e.NodeError = "Node update failed. Please check node values.";

To learn more, see Node Validation and Error Indication.