ACC2000: Error "Invalid key" When Adding Node to TreeView Control

• Microsoft Access 2000
• Microsoft Office 2000 Developer

SYMPTOMS

Advanced: Requires expert coding, interoperability, and multiuser skills.

When you try to use the Add method of the Node object with the TreeView control, you may receive the following error message:

Run-time error '35603':

Invalid key

CAUSE

The Item Method, which can be used to return a specific member of the Nodes collection, takes one argument. If this argument is a numeric expression, the Item method searches for the node by index; if the argument is a string expression, the Item method searches for the node by key. Because this argument is a Variant, the Item method cannot distinguish a key expression from an index expression, unless that expression contains at least one non-numeric character.

RESOLUTION

Concatenate at least one non-numeric character to the expression in the key argument of the Add method. For example, add a node by using

Set Node = Me!CustOrders.Nodes.Add(, , "Node " & rst!OrderID, _
           CStr(rst!OrderID)) 

Set Node = Me!CustOrders.Nodes.Add(, , rst!OrderID, CStr(rst!OrderID)) 

MORE INFORMATION

The sample code in this article uses Microsoft Data Access Objects. For this code to run properly, you need to reference the Microsoft DAO 3.6 Object Library.

Steps to Reproduce Behavior

1. Open the sample database Northwind.mdb.



2. Create a new form not based on any table or query.



3. Insert a Microsoft TreeView Control, version 6.0, and name it CustOrders.



4. Set the OnLoad property of the form to the following event procedure:




Private Sub Form_Load()
    Dim db As DAO.DATABASE
    Dim rst As DAO.Recordset
    Dim Node As Object

    Set db = CurrentDb()
    Set rst = db.OpenRecordset("Orders", dbOpenDynaset)

    If rst.RecordCount > 0 Then
        Do Until rst.EOF
            Set Node = Me!CustOrders.Nodes.Add(, , _
                       rst!OrderID,cstr(rst!OrderID))
            rst.MoveNext
        Loop
    End If

    rst.Close
    db.Close
End Sub 

5. Open the form in Form view. Note that you receive the following error message:

   Run-time error '35603':
   
   Invalid key

   The error occurs even if you use the CStr() function with the key argument (the third argument of the Add method).

REFERENCES

For more information about the Add method of the Node object, click Microsoft Visual Basic Help on the Help menu, type "Add Method (Nodes Collection)" in the Office Assistant or the Answer Wizard, and then click Search to view the topics returned.

For more information about the Item method, click Microsoft Visual Basic Help on the Help menu, type "Item method" in the Office Assistant or the Answer Wizard, and then click Search to view the topics returned.

Additional query words:

Keywords          : kbcode kberrmsg 
Version           : WINDOWS:2000; :
Platform          : WINDOWS 
Issue type        : kbprb 

Last Reviewed: May 13, 1999