C #, winform, Treeview, select a node, select all the corresponding child nodes, cancel the node, and cancel the parent node. tips:

During development, the Treeview control is often used to display the organizational structure, directory structure, and attribute checkedboxs.

The following is an example of selecting and canceling a node. If a node has a subnode, you can select all the subnodes. If you cancel the selected status of a node, if both the current node and the parent node exist, the selection of the parent node will be canceled.

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CodeAs follows:

Code
Using System;
Using System. Collections. Generic;
Using System. componentmodel;
Using System. Data;
Using System. drawing;
Using System. text;
Using System. Windows. forms;

namespace windowsapplication6
{< br> Public partial class treeviewtest: form
{< br> Public treeviewtest ()
{< br> initializecomponent ();
}

private void treeviewtest_load ( Object sender, eventargs e)
{< br> treeview1.expandall ();
}

Private VoidTreeviewappsaftercheck (ObjectSender, treevieweventargs E)
{

If (E. Action = Treeviewaction. bymouse)
{
Textbox1.text = E. node. text;
If (E. node. Checked)
{
// Cancels the selected status of all parent nodes.
Setchildnodecheckedstate (E. node, True );

}
Else
{
// Cancels the selected status of all parent nodes.
Setchildnodecheckedstate (E. node, False );
// If a parent node exists, deselect the selected status of the parent node.
If (E. node. Parent ! =   Null )
{
Setparentnodecheckedstate (E. node, False );
}
}
}
}
// Cancels the selected status of all parent nodes.
Private   Void Setparentnodecheckedstate (treenode currnode, Bool State)
{
Treenode parentnode = Currnode. parent;

Parentnode. Checked = State;
If (Currnode. Parent. Parent ! =   Null )
{
Setparentnodecheckedstate (currnode. Parent, State );
}
}
// After a node is selected, all the child nodes of the node are selected.
Private   Void Setchildnodecheckedstate (treenode currnode, Bool State)
{
Treenodecollection nodes = Currnode. nodes;
If (Nodes. Count > 0 )
Foreach (Treenode TN In Nodes)
{

Tn. Checked = State;
Setchildnodecheckedstate (TN, State );
}
}
}
}