Q:

How to get treeview control of one form in another form?

I am using a custom control in which there is a
treeview with some nodes .

I am providing user an option to add new node in the selected node by right click.
For this ,I am opening a Form in which user gives the new name in the text box and press add button , Now if there is no node with the same name then there is a node added into the selected 
treeview.

My problem is that i am not be able to add the node at the runtime with the new name.
I need this
treeview

in my Form but i am not be able to do this.
I am opening the form from my custom control
addInTreeView() method call

in which i am opening this form like this :
Form_NewForm.ShowDialog();

How can i do this?

A:

You dont' neccessarily need the treeview in your "new form". If I understand you correct the "new form" is simply shown to the user to enter a name for a new tree node.
Go the other way round: get the entered name from the textbox in your "main form".  
Something like this in your mainform that holds the treeview (pseudo-codish):  
string newNodeName = null;
Form_NewForm.FormClosing += delegate (Object s, FormClosingEventArgs e) {
    newNodeName = textBox_newName.Text;
}
Form_NewForm.ShowDialog();

if(!String.IsNullOrEmpty(newNodeName)) {
    //add new node to treeview
}

Most likely this concept has to be extended to check if the user cancelled the operation, because you don't want to create a new node if the user clicked "Cancel".

