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In C#, how to set all tree nodes checked true just after treeview loaded [duplicate]

This question already has an answer here:
How to Check or Uncheck All Child Nodes in TreeView
(1 answer)
Closed 3 years ago.
I have a TreeView in a WindowForm build in C#. In that treeview, files are being loaded successfully. I've also implemented checkboxes, showing in front of each tree node.
Now, I want all checkboxes to be checked true by default after all directories are loaded in treeview.
I tried the following code but no luck. It just checks true only the root node, not all the sub-nodes.
The first method btnDirectoryPath_Click(object sender, EventArgs e) is for button click which selects the path of the directory being loaded. From here, I am calling setAllCheckedTrue(TreeView treeView1)
private void btnDirectoryPath_Click(object sender, EventArgs e)
{
folderBrowserDialog1.SelectedPath = txtDirectoryPath.Text;
DialogResult drResult = folderBrowserDialog1.ShowDialog();
if (drResult == System.Windows.Forms.DialogResult.OK)
{
txtDirectoryPath.Text = folderBrowserDialog1.SelectedPath;
// Setting Inital Value of Progress Bar
progressBar1.Value = 0;
// Clear All Nodes if Already Exists
treeView1.Nodes.Clear();
toolTip1.ShowAlways = true;
if (txtDirectoryPath.Text != "" && Directory.Exists(txtDirectoryPath.Text))
{
//Loading all directories and sub directories and files
LoadDirectory(txtDirectoryPath.Text);
//setting all checkboxes true by default on loading.
setAllCheckedTrue(treeView1);
}
else
MessageBox.Show("Select Directory!!");
}
}
private void setAllCheckedTrue(TreeView treeView1)
{
foreach(TreeNode treeNode in treeView1.Nodes)
{
treeNode.Checked = true;
}
}
Following is snapshot of my treeview -
Another doubt is, How to handle on treeview load event? Is there any specific thing in c# to detect treeview load event?
I am a beginner to C#, Please help me out if possible. Thanks!

You need a recursive function to check all the subnodes as well. The TreeView does not do this automatically.
You also have to consider how to handle the update of parent nodes, when you unselect a subnode.
Try something like this for setting the subnodes as well:
private void SetAllCheckedTrue(TreeView treeView1)
{
foreach(TreeNode treeNode in treeView1.Nodes)
{
SetTreeNodeCheckbox(treeNode , true);
}
}
private void SetTreeNodeCheckbox(TreeNode treeNode , bool value)
{
treeNode.Checked = value;
foreach(var subNode in currentNode)
{
SetTreeNodeCheckbox(subNode, value);
}
}

First replace the below code
setAllCheckedTrue(treeView1);
with the below instructions
foreach(TreeNode node in treeView1.Nodes)
{
setAllCheckedTrue (node);
}
This will change the type of parameter sent to function "setAllCheckedTrue" that will become a node and not a treeview, and update the setAllCheckedTrue function with the below function
private void setAllCheckedTrue(TreeNode node)
{
node.Checked = true;
foreach(TreeNode childnode in node.Nodes)
{
setAllCheckedTrue (childnode);
}
}
Cordially

how to check a check box in tree-view when a tree-view node is selected / clicked in c#

in c# windows application i have a tree view with different nodes associated with Check Box for each node(this is for multiple Node Selection). how to change the Check Box property to checked when we click on respective node?

private void treeView1_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
TreeNode node = e.Node;
node.Checked = true;
}
Try this event ...

What event to capture when a TreeVew node is checked/unchecked

I have a node cbNode5 in a TreeView that contains 5 child nodes and I am trying to somehow capture the checking and unchecking of cbNode5 so I can mark the child nodes and check/unchecked to match the parent node. I know how to work though the nodes to check/uncheck the child nodes but what I can not figure out is what, and how to capture, the event that fires when the user checks the checkbox for a nod via either mouse click or keyboard.
I have tried the AfterCheck event but it does not seem to be working (and I do know the line to set the check box to true works as it runs fine under other events):
private void tvSteps_AfterCheck(object sender, TreeViewEventArgs e)
{
tvSteps.Nodes["cbStep1"].Checked = true;
}

Look at the AfterCheck event...
The AfterCheck() event is working fine for me:
private void tvSteps_AfterCheck(object sender, TreeViewEventArgs e)
{
if (e.Node.Name == "cbNode5")
{
foreach (TreeNode tn in e.Node.Nodes)
{
tn.Checked = e.Node.Checked;
}
}
}
When I check/uncheck cbNode5, its children check/uncheck to match it.
Are you sure the key you are using is correct?

I'd like to note that I resolved this problem by going into my TreeViewForm.Designer.CS, InitializeComponent function and adding the following line into the properties of the treeview object causing the problem:
this.treeView1.AfterCheck += new System.Windows.Forms.TreeViewEventHandler(this.treeView1_AfterCheck);
Note that your object names will differ from my own.
For some reason the AfterSelect event handler was added programatically to my form's Designer.CS file but my AfterCheck event handler was not.

Try this
TreeView.AfterCheck Event

To accomplish this task, you can handle the TreeList.AfterCheckNode event and set the TreeListNode.Checked property manually. Here is a sample code snippet:
private void treeList1_AfterCheckNode(object sender, DevExpress.XtraTreeList.NodeEventArgs e)
{
if (e.Node.ParentNode != null)
e.Node.ParentNode.Checked = IsAllChecked(e.Node.ParentNode.Nodes);
else
SetCheckedChildNodes(e.Node.Nodes);
}
private void SetCheckedChildNodes(TreeListNodes nodes)
{
foreach (TreeListNode node in nodes)
node.Checked = node.ParentNode.Checked;
}
private bool IsAllChecked(DevExpress.XtraTreeList.Nodes.TreeListNodes nodes)
{
bool value = true;
foreach (TreeListNode node in nodes)
{
if (!node.Checked)
{
value = false;
break;
}
}
return value;
}

Which object was the chosen option from ContextMenuStrip

I make windows form application. I have on form TreeView, I add few nodes and add ContextMenuStrip.
var menu = new ContextMenuStrip();
menu.Items.Add("Some text", new Bitmap(1, 1), new EventHandler(function_name));
var treeView = new TreeView(..);
treeView.ContextMenuStrip = menu;
treeView.Nodes.Add(new TreeNode()
{
...
Tag = someObject
});
My problems is how can I check in function function_name on which treeNode was clicked and chosen option from ContextMenuStrip
edit
function_name sygnature
public void pokaz_DoubleClick(object sender, EventArgs e)
{
}

You can handle the TreeNodeMouseClick event. In your TreeNodeMouseClickEventHandler you will have access to a TreeNodeMouseClickEventArgs argument. This argument contains a number of properties you can use to check which mouse button was clicked on which node. For example.
private TreeNode rightClickeNode;
void treeView1_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
rightClickedNode = e.Node;
}
}
You can then access rightClickedNode from your function_name.

what is the signature of the function_name method?
generally you can check the content of the sender parameter but it could happen it is the TreeView and not the TreeNode, if so you can check the properties of the e parameter.
Another way is that at every mouse down you make sure you select the node under the mouse in the TreeView so when function_name executes you get your node taking treeview.SelectedNode

You can make the node selected right before the Context Menu is shown and then you just need to check the SelectedNode property. Something like this:
private void treeView_MouseDown(object sender, MouseEventArgs e)
{
//See what node is at the location that was just clicked
var clickedNode = treeView.GetNodeAt(e.Location);
//Make that node the selected node
treeView.SelectedNode = clickedNode;
}
private void function_name(object sender, EventArgs e)
{
var currentNode = treeView.SelectedNode;
//Do something with currentNode
}

Find node clicked under context menu

How can I find out which node in a tree list the context menu has been activated? For instance right-clicking a node and selecting an option from the menu.
I can't use the TreeViews' SelectedNode property because the node is only been right-clicked and not selected.

You can add a mouse click event to the TreeView, then select the correct node using GetNodeAt given the mouse coordinates provided by the MouseEventArgs.
void treeView1MouseUp(object sender, MouseEventArgs e)
{
if(e.Button == MouseButtons.Right)
{
// Select the clicked node
treeView1.SelectedNode = treeView1.GetNodeAt(e.X, e.Y);
if(treeView1.SelectedNode != null)
{
myContextMenuStrip.Show(treeView1, e.Location);
}
}
}

Here is my solution. Put this line into NodeMouseClick event of the TreeView:
((TreeView)sender).SelectedNode = e.Node;

I find the standard windows treeview behavior selection behavior to be quite annoying. For example, if you are using Explorer and right click on a node and hit Properties, it highlights the node and shows the properties dialog for the node you clicked on. But when you return from the dialog, the highlighted node was the node previously selected/highlighted before you did the right-click. I find this causes usability problems because I am forever being confused on whether I acted on the right node.
So in many of our GUIs, we change the selected tree node on a right-click so that there is no confusion. This may not be the same as a standard iwndos app like Explorer (and I tend to strongly model our GUI behavior after standard window apps for usabiltiy reasons), I believe that this one exception case results in far more usable trees.
Here is some code that changes the selection during the right click:
private void tree_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{
// only need to change selected note during right-click - otherwise tree does
// fine by itself
if ( e.Button == MouseButtons.Right )
{
Point pt = new Point( e.X, e.Y );
tree.PointToClient( pt );
TreeNode Node = tree.GetNodeAt( pt );
if ( Node != null )
{
if ( Node.Bounds.Contains( pt ) )
{
tree.SelectedNode = Node;
ResetContextMenu();
contextMenuTree.Show( tree, pt );
}
}
}
}

Reviving this question because I find this to be a much better solution.
I use the NodeMouseClick event instead.
void treeview_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
if( e.Button == MouseButtons.Right )
{
tree.SelectedNode = e.Node;
}
}

This is a very old question, but I still found it useful. I am using a combination of some of the answers above, because I don't want the right-clicked node to become the selectedNode. If I have the root node selected and want to delete one of it's children, I don't want the child selected when I delete it (I am also doing some work on the selectedNode that I don't want to happen on a right-click). Here is my contribution:
// Global Private Variable to hold right-clicked Node
private TreeNode _currentNode = new TreeNode();
// Set Global Variable to the Node that was right-clicked
private void treeView_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Right)
_currentNode = e.Node;
}
// Do something when the Menu Item is clicked using the _currentNode
private void toolStripMenuItem_Clicked(object sender, EventArgs e)
{
if (_currentNode != null)
MessageBox.Show(_currentNode.Text);
}

Similar to Marcus' answer, this was the solution I found worked for me:
private void treeView_MouseClick(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
treeView.SelectedNode = treeView.GetNodeAt(e.Location);
}
}
You need not show the context menu yourself if you set it to each individual node like so:
TreeNode node = new TreeNode();
node.ContextMenuStrip = contextMenu;
Then inside the ContextMenu's Opening event, the TreeView.SelectedNode property will reflect the correct node.

If you want the context menu to be dependent on the selected item you're best move I think is to use Jonesinator's code to select the clicked item. Your context menu content can then be dependent on the selected item.
Selecting the item first as opposed to just using it for the context menu gives a few advantages. The first is that the user has a visual indication as to which he clicked and thus which item the menu is associated with. The second is that this way it's a hell of a lot easier to keep compatible with other methods of invoking the context menu (e.g. keyboard shortcuts).

Here is how I do it.
private void treeView_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Right)
e.Node.TreeView.SelectedNode = e.Node;
}

Another option you could run with is to have a global variable that has the selected node. You would just need to use the TreeNodeMouseClickEventArgs.
public void treeNode_Click(object sender, TreeNodeMouseClickEventArgs e)
{
_globalVariable = e.Node;
}
Now you have access to that node and it's properties.

I would like to propose an alternative to using the click events, using the context menu's Opened event:
private void Handle_ContextMenu_Opened(object sender, EventArgs e)
{
TreeViewHitTestInfo info = treeview.HitTest(treeview.PointToClient(Cursor.Position));
TreeNode contextNode;
// was there a node where the context menu was opened?
if (info != null && info.Node != null)
{
contextNode = info.Node;
}
// Set the enabled states of the context menu elements
menuEdit.Enabled = contextNode != null;
menuDelete.Enabled = contextNode != null;
}
This has the following advantages that I can see:
It does not change the selected node
No separate event handler needed to store the target node instance
Can disable menu items if the user right-clicks empty space in the TreeView
Note: if you worry that the user may have already moved the mouse by the time the menu is opened, it is possible to use the Opening event instead.