I have a treeView with many nodes. I want that some nodes change their image when node collapsed/expanded. How can I do it ?
Unfortunately, TreeNode don't have properties like ExpandNodeImage, CollapseNodeImage \
TreeView can change very often, so nodes can be deleted/added.. i can delete child nodes and so on...
Maybe, there is a class like ExpandAndCollapseNode ?
1). Add an ImageList Control to your WinForm.
2). Populate the ImageList with the pictures/icons you wish to change/display in response to what the user does at run-time with the TreeView, such as expanding, or collapsing nodes.
3). Assign the 'ImageList Control to the 'ImageList property of the 'TreeView
At this point you may want to make an initial pass over the TreeView, assuming it is populated, assigning the Node.ImageIndex property to point to the Image ... in the ImageList ... you want to use for the Node depending on whether it has children, or whatever.
4). If a user expands a Node, for example, you can use the BeforeExpand Event of the TreeView to change the Node's picture : like so : in this case we use the index of the Picture in the ImageList :
private void treeView1_BeforeExpand(object sender, TreeViewCancelEventArgs e)
{
e.Node.ImageIndex = 3;
}
5) You can also set the Node's image by using the ImageKey property which is the string name of the Image
6) There lots of other possible Node Picture variations to use : check out : SelectedImageIndex and SelectedImageKey : You can change Node pictures in the BeforeSelect, AfterSelect and BeforeExpand, events also, depending on the effect you are after.
BeforeCollapse
BeforeExpand
AfterCollapse
AfterExpand
Use both ImageIndex & SelectedImageIndex:
private void treeView_BeforeExpand(object sender, TreeViewCancelEventArgs e)
{
e.Node.ImageIndex = 1;
e.Node.SelectedImageIndex = 1;
}
TreeViews have the following events that will be be fired when nodes are collapsed/expaned.
BeforeCollapse
BeforeExpand
AfterCollapse
AfterExpand
It's better to use :
treeNode.SelectedImageIndex = 1;
you can use the events AfterCollapse & AfterExpand (that are avilable on the TreeView itself) to modify the image of a node.
you can get the node using the TreeViewEventArgs input parameter:
private void treeView1_AfterCollapse(object sender, TreeViewEventArgs e)
{
e.Node.ImageIndex = 1;
}
Related
I'm working on a form application in c# that includes TreeView in it. What I want to do is to attach a panel to each node so whenever user clicks on a node the panel will be updated according to the node selected.
The problem I'm facing is that when I select a node, the application does nothing but when I select another node then the application shows the content related to previously selected node. Means that App is always getting content related to last selected node not the current one. For Example If I'll select "Text" node, the label will show nothing and after that If I'll select some other node like "Appearance" the label will show "Text" which was the last selected node.
Following here is the image of my Form that contains TreeView.
For testing purpose I'm just storing the selected node's value in my label's text
Here's the code.
public partial class TextEditor_Preferences : Form
{
public TextEditor_Preferences()
{
InitializeComponent();
}
List<Panel> myPanels = new List<Panel>(); //Ignore this line of code !
private void SideBar_MouseClick(object sender, MouseEventArgs e)
{
label1.Text = SideBar.SelectedNode.ToString();
}
}
Can anobody suggest me a method?
If I'm missing something or question is not valid, Please let me know explicitly. Thanks
TreeView control has the AfterSelect event you should write your code in that handler.
public YourForm()
{
InitializeComponent();
treeView.AfterSelect += TreeViewAfterSelect;
}
private void TreeViewAfterSelect(object sender, TreeViewEventArgs e)
{
string nodeText = treeView.SelectedNode.Text;
// Update the panel here accordingly
}
Maybe try using the AfterSelect event rather than MouseClick. e.g.
private void Sidebar_AfterSelect(object sender, TreeViewEventArgs e)
{
label1.Text = e.Node.Text;
}
I am beginner in c#. In my project, I populated a xml file inside a TreeView control. If the xml file is large, the TreeView control is showing the data with scroll bars. Beside this, whenever the user double clicks a node I am showing a panel beside the selected node something like this..
When I scroll the TreeView Control :
My question is how to make the panel attached to treeView control so that eventhough the user scrolls the TreeView control the panel should also move along with the selected node.
Well, hard to do since TreeView doesn't have a Scroll event. It isn't reliable anyway since nodes can be expanded and collapsed, changing the position and visibility of the node. The backup plan is to use a Timer. This worked well:
private void timer1_Tick(object sender, EventArgs e) {
var node = treeView1.SelectedNode;
if (node == null || !node.IsVisible) panel1.Visible = false;
else {
panel1.Visible = true;
var nodepos = treeView1.PointToScreen(node.Bounds.Location);
var panelpos = panel1.Parent.PointToClient(nodepos);
panel1.Top = panelpos.Y;
}
}
I have a treeview. And i want to get the selected(clicked) node's path as a treeview again.
Is there any solution?
Example treeview;
.node1
.node1.1
.node1.2
.node2
.node2.1
.node2.2
.node2.3
.node2.3.1
.node2.3.2
when i click node2.3.2 than i want to get such a result:
node2
node2.3
node2.3.2
If you mean create another TreeView with the selected node as the root, then you'd clone the node, create a TreeView and then add the cloned node. I have a strange feeling that's not what you mean though....
Is this what you need?
TreeView ConvertTreeNodeToTreeView(TreeNode tn) {
TreeView tv = new TreeView();
tv.Nodes.Add(tn);
return tv;
}
protected void tv_SelectedNodeChanged(object sender, EventArgs e)
{
if (this.tv.SelectedNode != null) {
this.Panel1.Controls.Add(ConvertTreeNodeToTreeView(tv.SelectedNode));
}
}
I'm using a treeview-control in winforms and an imagelist to display different states of the treeview-elements.
But i don't want to use the selected element to use a different image.
Is there a way to disable SelectedImageIndex in the TreeView-control?
If tried to change the selectedimageindex after every selection. Something like this:
private void TreeView1AfterSelect(object sender, TreeViewEventArgs e)
{
treeView1.SelectedImageIndex = treeView1.SelectedNode.ImageIndex;
}
But this causes a pretty ugly flickering of the control after every selection..
When you are creating the new TreeNode, assign the same imageindex to ImageIndex and SelectedImageIndex:
...
node.SelectedImageIndex = node.ImageIndex;
...
When creating the node
Dim nd As New TreeNode("NodeKey", "NodeText", 1, 1)
The two indices are for ImageIndex and SelectedImageIndex.
I have a treeview1:
treenode--
treenode1--
treenode2
treenode3
You can select only node2 and node3 if you want to display them parameters. How can i block selecting node and node1? I try like that,but than you can select all nodes:
private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
{
...
}
you will have to use SelectAction Property on the tree node. you will need to set it on the node when you are creating them.
set selectaction=none on node and node1
If it's a win forms TreeView handle the BeforeSelect event and set the Cancel property of your TreeViewCancelEventArgs parameter to false. For web controls see Vinay's answer.