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System.NullReferenceException

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This is a migrated thread and some comments may be shown as answers.

Karl asked on 15 May 2010, 03:09 PM

I have a form in a WindowsApplication with just a RadTreeNode on it.

    
            Imports System  
        
            Imports Telerik.WinControls.UI  
        
            Public Class Form1  
        
                Inherits Form  
        
                Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load  
        
                    InitializeComponent()  
        
                    Dim node As RadTreeNode = RadTreeView1.Nodes("Email Contacts").Nodes.Add("Bob Tony")  
        
                    node.Selected = True 
        
                    RadTreeView1.Nodes("Email Contacts").Nodes.Add("Sue Winchell")  
        
                    RadTreeView1.Nodes("Email Contacts").Nodes.Add("Lui Sang")  
        
                    RadTreeView1.Nodes("Lists").Nodes.Add("Priorities")  
        
                    RadTreeView1.Nodes("Lists").Nodes.Add("Opportunities")  
        
                    RadTreeView1.Nodes("Lists").Nodes.Add("Issues")  
        
                End Sub 
        
            End Class

This is from your example.
On reaching this line:
Dim node As RadTreeNode = RadTreeView1.Nodes("Email Contacts").Nodes.Add("Bob Tony")
I keep getting the error:
System.NullReferenceException was unhandled
Message="Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt."

What's happening and how do I correct it?

Thanks in advance
Karl

System.NullReferenceException

2 Answers, 1 is accepted