CODEWITHSUNDEEP
c#treeview
Andrey Petrovich
Andrey Petrovich

Reputation: 41

TreeView Check/UnCheck all child items

How do i check/uncheck all child items in TreeView? Probably error happened when one of items become to selected state and child items checked/unchecked buggy.

Link to VS 2010 Project+Exe

Video on YOUTUBE

private void Form1_Load(object sender, EventArgs e)
    {
        treeView1.CheckBoxes = true;
        treeView1.BeginUpdate();
        treeView1.Nodes.Add("1111");
        treeView1.Nodes[0].Nodes.Add("2222");
        treeView1.Nodes[0].Nodes.Add("2222");
        treeView1.Nodes[0].Nodes.Add("2222");
        treeView1.Nodes[0].Nodes.Add("2222");
        treeView1.Nodes[0].Nodes[1].Nodes.Add("3333");
        treeView1.Nodes[0].Nodes[1].Nodes[0].Nodes.Add("4444");
        treeView1.Nodes[0].Nodes[1].Nodes[0].Nodes.Add("4444");
        treeView1.Nodes[0].Nodes[1].Nodes[0].Nodes.Add("4444");
        treeView1.EndUpdate();

        treeView1.ExpandAll();
    }

    private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
    {
        treeView1.BeginUpdate();

        foreach (TreeNode Node in e.Node.Nodes)
        {
            Node.Checked = e.Node.Checked;
        }

        treeView1.EndUpdate();
    }

Upvotes: 4

Views: 18550

Answers (5)

JavadTousi
JavadTousi

Reputation: 23

    private void CheckAllChildNodes(TreeNode treeNode, bool nodeChecked)
    {
        foreach (TreeNode node in treeNode.Nodes)
        {
            node.Checked = nodeChecked;
            if (node.Nodes.Count > 0)
            {
                this.CheckAllChildNodes(node, nodeChecked);
            }
        }
    }
    private void treeView_AfterCheck(object sender, TreeViewEventArgs e)
    {
        if (e.Action != TreeViewAction.Unknown)
        {
            if (e.Node.Nodes.Count > 0)
            {
                if (!e.Node.Checked)
                {
                    this.CheckAllChildNodes(e.Node, e.Node.Checked);
                }
            }
        }

        if (e.Node.Parent != null)
        {
            TreeNode n = e.Node;
            while (n.Parent != null)
            {
                if (n.Checked)
                {
                    n.Parent.Checked = true;
                }
                n = n.Parent;
            }
        }

    }

Upvotes: 0

Luiz Oliveira
Luiz Oliveira

Reputation: 11

The solution that I've figured out was the following:

  • To perform the selection I used Linq:

    if (e.Node.Nodes.Count > 0) e.Node.Nodes.Cast<TreeNode>().Where(tnc => tnc.Checked != e.Node.Checked).ForEach(tn => tn.Checked = e.Node.Checked);

  • Then to handle the event selection I extended the TreeView class: public class MyTV : TreeView { protected bool TopOfCascade; TreeNode startNode; public Action FinishedCheckEventsDelegate; public Action InitiateCascadeCheckEventsDelegate; public MyTV() : base() { TopOfCascade = false; startNode = null; } protected override void OnBeforeCheck(TreeViewCancelEventArgs e) { base.OnBeforeCheck(e); if (!TopOfCascade && !e.Cancel) { TopOfCascade = true; startNode = e.Node; if (InitiateCascadeCheckEventsDelegate != null) InitiateCascadeCheckEventsDelegate(); } } protected override void OnAfterCheck(TreeViewEventArgs e) { base.OnAfterCheck(e); if (startNode == e.Node && e.Action != TreeViewAction.Unknown) { if (FinishedCheckEventsDelegate != null) FinishedCheckEventsDelegate(); TopOfCascade = false; startNode = null; } } In the host control, you can hook the pre and post cascade events and iterate over all checked/unchecked tree nodes avoiding a lot of cross event firing. You control the cascade via some container.

I got the ForEach to IEnumerable from the following an implementation from the web:

public static void ForEach<T>(this IEnumerable<T> source, Action<T> action)
{
  if (source == null) throw new ArgumentNullException("source");
  if (action == null) throw new ArgumentNullException("action");
  foreach (T item in source)
  {
    action(item);
  }
}

Good Luck!

Upvotes: 1

محمد النعيمي
محمد النعيمي

Reputation: 570

    private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
    {

        if (e.Action != TreeViewAction.Unknown)
        {
            if (e.Node.Nodes.Count > 0)
            {
                /* Calls the CheckAllChildNodes method, passing in the current 
                Checked value of the TreeNode whose checked state changed. */
                this.CheckAllChildNodes(e.Node, e.Node.Checked);
            }

        }
    }

   private void CheckAllChildNodes(TreeNode treeNode, bool nodeChecked)
    {
        foreach (TreeNode node in treeNode.Nodes)
        {
            node.Checked = nodeChecked;
            if (node.Nodes.Count > 0)
            {
                // If the current node has child nodes, call the CheckAllChildsNodes method recursively. 
                this.CheckAllChildNodes(node, nodeChecked);
            }
        }
    }

Upvotes: 0

Kamil
Kamil

Reputation: 13931

Here is an answer (from Hans Passant):

Winforms treeview, recursively check child nodes problem

Im writing it as answer, not comment to make it easier to find.

Upvotes: 0

MethodMan
MethodMan

Reputation: 18843

using your code that you have in the Form_Load keep that code it works and add these 2 methods in your code 

private void Form1_Load(object sender, EventArgs e)
{
    treeView1.CheckBoxes = true;
    treeView1.BeginUpdate();
    treeView1.Nodes.Add("1111");
    treeView1.Nodes[0].Nodes.Add("2222");
    treeView1.Nodes[0].Nodes.Add("2222");
    treeView1.Nodes[0].Nodes.Add("2222");
    treeView1.Nodes[0].Nodes.Add("2222");
    treeView1.Nodes[0].Nodes[1].Nodes.Add("3333");
    treeView1.Nodes[0].Nodes[1].Nodes[0].Nodes.Add("4444");
    treeView1.Nodes[0].Nodes[1].Nodes[0].Nodes.Add("4444");
    treeView1.Nodes[0].Nodes[1].Nodes[0].Nodes.Add("4444");
    treeView1.EndUpdate();
    treeView1.ExpandAll();
}

private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
{
    foreach (TreeNode childNode in e.Node.Nodes)
    {
        childNode.Checked = e.Node.Checked;
    }
}

Upvotes: 5

Related Questions