I am building a searchable TreeView (treeView1), which will remove any TreeNode that do not contain the search keyword. However, I would like to reset the tree back to its original structure on the click of a button. I am storing the original treeview in a variable before the search is performed.
TreeView originalTreeView = new TreeView();
originalTreeView = treeView1;
I then perform the search, which is likely to remove some TreeNodes.
treeView1.searchTree(keyword);
Then, when I click the Reset button, I would like treeView1 to once again show the full originalTreeView, which is what I cannot figure out how to do.
private void resetBtn_Click(object sender, EventArgs e) {
treeView1 = originalTreeView;
}
This code does nothing (the listener is OK). Is it possible to do something like this, or do I have to populate the tree all over again every time?
Your code are assign the reference to originalTreeView only, but not copy/clone as a new object (backup).
Please try this Copy all treeView parent and children to another treeView c# WinForms
Related
I added a treeview to my main form, right-clicking opens a contextmenu where you can add new nodes to the tree (in this case categories).
It creates, then adds the node and calls BeginEdit()...
private void addCategoryToolStripMenuItem_Click(object sender, System.EventArgs e)
{
var category = new TreeNode();
tvCategories.Nodes.Add(category);
category.BeginEdit();
}
...and then this:
From the info I gathered this should work just fine, howeeeeever:
Any ideas? :)
Just a kind of extension: the problem doesn't lie within BeginEdit(), I can't edit the label at all. I still don't know why, but now I know I need to look somewhere else.
Your initial node can't be blank, so fill it with some kind of text:
var category = new TreeNode("abc");
While I'm still not entirely sure why, the above code created a node that was uneditable even though the LabelEdit property was true.
This however seems to do the trick:
private void addCategoryToolStripMenuItem_Click(object sender, System.EventArgs e)
{
tvCategories.Nodes.Add(new TreeNode("category"));
tvCategories.Nodes[tvCategories.Nodes.Count - 1].BeginEdit();
}
The 1st line creates and adds the new node, what's important here is that you provide an initial string even if the user has to change it. Why? Not sure. But leaving the string part empty results in the above problem.
The 2nd line just selects the last node.
I'm trying to actually deselect all nodes in my TreeView. By "actually", I mean that TreeView1.SelectedNode = null; will actually deselect the node in the tree.
Right now, visually speaking, the node is deselected. However, when I try to add a new node, the treeview will automatically select the first node in the tree (at the top) and create a subnode when ideally I want to create a parent node. I can't just deselect the selected node before adding either, because the user might want to add a child node. The behaviour I'd like is for the parent/child node adding to be based on what is selected in the treeview. If nothing is selected, add a parent, if something is selected, add a child in that selected node.
I construct a TreeNode object called node in a function with images and text and all that then I have the following:
if (tvContent.SelectedNode == null)
tvContent.Nodes.Add(node);
else
{
tvContent.SelectedNode.Nodes.Add(node);
tvContent.SelectedNode.Expand();
}
I have a "Deselect All" button that is supposed to make the above code work. The code for that button is simply:
tvContent.SelectedNode = null;
Pardon my tagging both C# and VB.NET. I'm good with both so if someone can help me out in either language that'd be terrific!
Thanks
EDIT:
Interesting. It seems that while testing if the selected node is null, .NET will automatically set the selected node to the first node in the tree. The following code shows the "trigger" message box, but immediately selects the first node in the tree after the if statement is complete.
private void btnDeselectAll_Click(object sender, EventArgs e)
{
tvContent.SelectedNode = null;
if (tvContent.SelectedNode == null) MessageBox.Show("trigger");
}
EDIT2: The issue lies in using an InputBox for the title input of the node. For whatever reason, that changes the selected node of the treeview. I tried this in a stock project and managed to replicate the issue. I guess there's no fixing this :S
So it turns out that getting "true" deselection isn't possible. As soon as the treeview loses focus then gains focus again (e.g. via an inputbox window popping up), the selected node will no longer be null.
My work around was to introduce a panel that becomes visible with some input options so that node title input is done on the main form instead of on another form. I don't like this fix but it's all that can be done.
This worked for me
Private LastSelectetNode As TreeNode
Protected Overrides Sub OnBeforeSelect(e As TreeViewCancelEventArgs)
e.Cancel = LastSelectetNode Is Nothing
MyBase.OnBeforeSelect(e)
End Sub
Protected Overrides Sub OnMouseUp(e As MouseEventArgs)
Dim nd = MyBase.HitTest(e.Location).Node
If LastSelectetNode Is nd Then
SelectedNode = Nothing
LastSelectetNode = Nothing
Else
LastSelectetNode = nd
End If
MyBase.OnMouseUp(e)
End Sub
I tried to reproduce your scenario but failed. After setting SelectedNode to null, it remained null for me when trying to read it back. A few things I want to check on:
Are you sure you're actually deselecting the node? If you have the "HideSelection" property of the TreeView set to True (default), the selection disappears anytime the TreeView loses focus (like when you click your deselect all button - making it look like it's working). Make sure this isn't the case by setting HideSelection to False.
Are you sure you're not triggering an event handler (like SelectedNodeChanged) when you set the SelectedNode to null?
I'd like to programmatically emulate a click on a node in a TreeView control. There's no clickable method as far I can see (something corresponding to other controls) and I guess that I need to go for the currently selected node.
So I've tried the following:
christmasTreeView.SelectedNode. ???
However, intellisense gave me no hint on what to call in order to fire a clickety-click on the node. How can it be done?
You can do something like:
// find the node you want to select and make it the SelectedNode
christmasTreeView.SelectedNode = christmasTreeView.Nodes[1]; // <-- the index you need
// Now trigger a select
christmasTreeView.Select();
// or
//christmasTreeView.Focus();
This will fire:
private void christmasTreeView_AfterSelect(object sender, TreeViewEventArgs e) {
// awesome
}
Possible approach (not very smooth, though).
TreeNode preSelected = ChristmasTreeView.SelectedNode;
ChristmasTreeView.SelectedNode = null;
ChristmasTreeView.SelectedNode = preSelected;
ChristmasTreeView.Select();
Your main issue is that a Windows Forms TreeNode does not derive from a Control like a TreeView does (or, for example, a Button). It's much closer to a "model" class, meaning that it's primarily concerned with the hierarchical organization of your data. Although some of the presentational abstraction is leaked in properties like Color, Bounds, Handle and similar, a TreeNode doesn't know how to paint itself, nor how to handle click events.
On the other hand, a TreeView is an actual Control, meaning you can derive from it and be able to override its protected OnClick method, like shown in the example you linked.
If you want to follow that path, you could create your derived TreeView class from it and override the protected OnNodeMouseClick method. This method is specific to the TreeView and called by its WndProc method when a certain node is clicked.
But having read your comments to other answers, it seems that this is not what you really need to do to accomplish your goal.
You need to use event handler for TreeView.NodeMouseClick.
This Event got parameter which You can call in Your EventHandler like below:
void MyTreeview_NodeMouseClick(object sender,
TreeNodeMouseClickEventArgs e)
{
// do something with e.Node
}
For a project I am doing, I'm trying to create 16 panels onto a WinForm, via two for loops. Then once those panels have been placed on the form loadup, I'm trying to have a MouseClick event for each panel. Only problem is accessing them. The panels are placed properly onto the winform, but I have no way of accessing them. I tried putting them into a List, but everytime I add them the list turns out to be empty. This is my code:
Anyone have suggestions toward a solution?
To start off, the list is always empty because it was declared static, I would guess that if you just made it a private member, then the list will work as expected (since you will be trying to access it outside of a static context). In any case, I would do something like this:
Well, first thing's first, I would create a dictionary like this:
Dictionary<string, Panel> formsPanels; // Initialize in form's constructors
Then, I would register each panel's mouse click event within the for loop(s) (i.e. panel.MouseClick += new EventHandler(eventMethod)), and assign each panel an unique name (I would use something like panel1, panel2, etc), then add that panel to the formsPanels using its name as the key. Then within the event, you can query which panel was clicked using something like this:
public void MouseClick(object sender, EventArgs e)
{
var panel = sender as Panel;
if(panel == null) // check if the sender is a panel
return;
// Your Code
}
I didn't verify any issues within my code, so I apologize for any errors that occur. In any case, hope that helps.
I'm using DevExpree XtraTreeList Control, I want to randomly Set one of the first levels nodes to be the first node in the Tree, nothing helpful shown in the TreeList Control's Methods nor in the TreeListNode Methods,
Please Advice.
Edit: My Code
private void btnSetMaster_ButtonClick(object sender, DevExpress.XtraEditors.Controls.ButtonPressedEventArgs e)
{
//Load reprot
if (treeLstRprtDS.FocusedNode != null)
{
treeLstRprtDS.SetNodeIndex(treeLstRprtDS.FocusedNode,0);
//Get selected underlying object
ReportDataSource rprtDataSourceSelected =
(ReportDataSource)treeLstRprtDS.GetDataRecordByNode(treeLstRprtDS.FocusedNode);
theReport.SetReportDataSourceAsMaster(rprtDataSourceSelected);
}
}
Edit:
Note: working on bound mode
Solution:
I implemented the CompareNodeValues Event for the XtrTreeList Control
Read here...
and then forced the tree to do sorting using Column.SortIndex Read here...
Do you wish to scroll the TreeList so that a certain node to be the top one? If so, use the TreeList's TopVisibleNodeIndex property. If you need a certain node to be the first one, you should sort the TreeList within its CompareNodeValues event handler.
It sounds like you're looking for the SetNodeIndex method.