System.NullReferenceException -- tag -- treeview

[Adie]

Hi, I can't seem to use the tag property of the treeview without craching
my app. The basic code:

while(SqlProducts.Read())
{
TreeNode childNode = new TreeNode(SqlProducts.GetString(0));
cnode.Tag = "Product Details";
parentNode.Nodes.Add(childNode);
}


private void treeProducts_AfterSelect( object sender,
System.Windows.Forms.TreeViewEventArgs e)
{
text1.text = e.Node.Tag.ToString();
}

There is a QB article which addresses the issue in VB but not C#, anyone
know how to fix it?

Also, why is private void treeProducts_AfterSelect( ... ) called on the
load of the form?

Thanks!

 

[Adie]

There is a QB article which addresses the issue in VB

Forgot to add the link:
http://support.microsoft.com/default.aspx?scid=kb;en-us;316180

 

[Adie]

Hi, I can't seem to use the tag property of the treeview without craching
my app. The basic code:

while(SqlProducts.Read())
{
TreeNode childNode = new TreeNode(SqlProducts.GetString(0));
cnode.Tag = "Product Details";
parentNode.Nodes.Add(childNode);
}


private void treeProducts_AfterSelect( object sender,
System.Windows.Forms.TreeViewEventArgs e)
{
text1.text = e.Node.Tag.ToString();
}

Ok, it appears that I have to check for null

private void treeProducts_AfterSelect( object sender,
System.Windows.Forms.TreeViewEventArgs e)
{
if (e.Node.Tag != null)
label1.Text = e.Node.Tag.ToString();
}

stupid nulls.