Initially, I want nothing selected on my TreeView. By default, the first node is selected/focused.The code
treeView1.SelectedNode = null;
didn't work.
The tree node is not selected but has tap stop
treeView1.SelectedNode = null;
treeView1.TabStop = false;
Put your line of code
treeView1.SelectedNode = null;
in the Form.Shown event, rather than in the Form.Load event. The default selection occurs after Form.Load, so you want to clear the selection after that.
Put your line of code
TreeView.HideSelection = false;
Related
I've got a problem with adding some controls into a Panel(which gets "PopUpped" by a ModalPopupExtender) and add a CheckedChanged-EventHandler.
First of all, when user clicks on a button, this happens inside the CreatePanelChoose() function:
foreach (ListItem item in lbSupplier.Items)
{
string cbid = "cb" + i;
CheckBox cb = new CheckBox();
cb.ID = cbid;
cb.Text = item.Text;
cb.AutoPostBack = true;
AjaxControlToolkit.MutuallyExclusiveCheckBoxExtender mecbe = new AjaxControlToolkit.MutuallyExclusiveCheckBoxExtender();
mecbe.ID = "mecbe" + cbid;
mecbe.TargetControlID = cbid;
mecbe.Key = "SupplierKEY";
mecbe.BehaviorID = mecbe.ID + i;
//Also adding a Label
phModalPopupExtender.Controls.Add(new LiteralControl("</br>")); //phModalPopupExtender is a PlaceHolder
phModalPopupExtender.Controls.Add(cb);
phModalPopupExtender.Controls.Add(mecbe);
phModalPopupExtender.Controls.Add(lbl);
AsyncPostBackTrigger trigger = new AsyncPostBackTrigger();
trigger.ControlID = cbid;
trigger.EventName = "CheckedChanged";
UpdatePanelMatrix.Triggers.Add(trigger);
i++;
ButtonOK.Enabled = false;
}
lblText.Text = "Select one Supplier";
ModalPopupExtender1.Show();
Then i add the EventHandler in the Page_LoadComplete:
As you can see it also gets asigned to the control (I think).
The ModalPopup shows up correctly, but if I click one of the CheckBox, then it just closes it without going into cb_CheckedChanged, but it makes a Async postback ...
If I check Request.Form["__ASYNCPOST"] its true and Request.Form["__EVENTTARGET"] is also correct. (It gives me the unique id!)
Request.Form["__EVENTARGUMENT"] is empty.
I think I also need to say that I use a masterpage.
The problem shouldn't be the lifecycle of the page, because msdn says:
LoadComplete
Raised at the end of the event-handling stage.
Use this event for tasks that require that all other controls on the page be loaded.
Its the onliest place it makes me think it would be right.
Btw: yes i looked trough the topics here allready, but nothing helped me ... (google fo sure also)
Edit 1:
if (IsPostBack)
{
if (recreating == true)
{
CreatePanelChoose();
}
}
In CreatePanelChoose i do the foreach now everytime when its a postback! But it still doesnt fire cb_ChangedChecked ...
Edit 2:
MSDN-Page-Lifecycle also says:
PreInit
Raised after the start stage is complete and before the initialization
stage begins.
Use this event for the following:
Create or re-create dynamic controls.
So i tried to recreate the Panel there. But i dont have the ListItems there to get the values ... ?!
Okay, gave up ...
If someone would still have an answer, it would be great!
Right now I dont use the OnCheckedChanged-Event of the CheckBoxes anymore.
I just let them select a CheckBox and on the OnClick of the ButtonOk I loop through the CheckBoxes and check which one is selected.
I have a TreeView control for which each node in it I want to share a ContextMenuStrip which has two ToolStripMenuItems ie:
this.BuildTree = new MyApp.MainForm.TreeView();
this.ItemMenuStrip = new System.Windows.Forms.ContextMenuStrip(this.components);
this.DeleteMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.ShowLogMenuItem = new System.Windows.Forms.ToolStripMenuItem();
...
this.ItemMenuStrip.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
this.DeleteMenuItem,
this.ShowLogMenuItem});
So I show and hide these to items according to certain criteria on a right click in a MouseUp event. When both are hidden I hide the ContextMenuStrip itself. Problem is when I hide the ContextMenuStrip it seems the next time I want to show one of the menu items I have to click twice on the node. The strange thing is on the first click to reshow one or both of the the items I have the following code:
ItemMenuStrip.Visible = true;
ShowLogMenuItem.Visible = true;
The two lines above don't seem to do anything ie both remain false in the debugger view after stepping over each line.
I don't think I've got any events on these values being set at least I don't have any events attached.
What am I doing wrong?
I suggest you to set:
this.BuildTree.ContextMenuStrip = this.ItemMenuStrip;
to make the menu automatically open on tree right-click.
Then subscribe ItemMenuStrip.Opening event to change the visibility of items and the contextmenu itself:
void ItemMenuStrip_Opening(object sender, CancelEventArgs e)
{
if (something)
{
e.Cancel = true; // don't show the menu
}
else
{
// show/hide the items...
}
}
If you need to know the current position of the clicked point (e.g. to check if a tree node is clicked), you can use Control.MousePosition property. Note that MousePosition is a point in screen coordinates, so you need to call treeView1.PointToClient(position) to get the tree coordinates e.g. :
private void ItemMenuStrip_Opening(object sender, CancelEventArgs e)
{
var pointClicked = this.BuildTree.PointToClient(Control.MousePosition);
var nodeClicked = this.BuildTree.GetNodeAt(pointClicked);
if (nodeClicked == null)
{
// no tree-node is clicked --> don't show the context menu
e.Cancel = true;
}
else
{
// nodeClicked variable is the clicked node;
// show/hide the context menu items accordingly
}
}
So figured out what was going wrong I was setting Visible on this.ItemMenuStrip rather than the this.BuildTree.ContextMenuStrip.
This seems rather strange to me as I would have thought BuildTree.ContextMenuStrip was just a direct reference to the ItemMenuStrip but apparently not.
I used this code below to Enable/Disable Button Control inside my usercontol on my Form which works perfect.
var btnAdd = this.userControlCommonTask1.Controls.Find("btnAdd", true);
btnAdd[0].Enabled = true;
But when i use toostrip(toolstrip1) with buttons (btnAdd,btnEdit,btndelete etch..) and use my code above
I got:
Index was outside the bounds of the array.
I tried this one but it only works in toolstrip.
var btnAdd = this.userControlCommonTask1.Controls.Find("toolstrip1", true);
btnAdd[0].Enabled = true;
Thanks in Regards
I already Solve my Problem:
var toolstrip1 = this.userControlCommonTask1.Controls.Find("toolstrip1", true);
var toolstrip1Items = toolstrip1[0] as ToolStrip; <-- set to toolstrip control
var btnRead = toolstrip1Items.Items.Find("btnRead", true); <--get BtnRead on toolstrip Item.Find
btnRead[0].Enabled = false; <--disable/Enable btn
This can be a reference for other Developers.
Cheers!
Try a 0 instead of 1 your array is zero based
Toolstrip is another usercontrol. Try make a reference to it and then find it's child controls
ie. ctlTooolStrip.Controls.Find("BtnAdd",true);
Also try toolStrip.Items
I would need to know how to let the programatically selected node make graphically in the state "selected" like the user clicked on it. SelectedNode only makes this one internally selected. Thank you very much!
The reason it does not show as highlighted is due to the tree view not having focus. This is in a button click event on my test form:
TreeView1.SelectedNode = TreeView1.Nodes(2);
TreeView1.Focus();
Which highlights the node properly. if you remove the Focus(); call it doesn't highlight until you click into the tree view (anywhere in the tree view, not necessarily on to the node that you want to be selected).
TreeView1.SelectedNode.BackColor = SystemColors.HighlightText; // This will work
Above solutions will only set the focus on it but will not change the highlight view of it.
This works for me for .net 3.5:
Set the treeview component's DrawMode property to: OwnerDrawAll
Then in the DrawNode event write the following:
if (((e.State & TreeNodeStates.Selected) != 0) && (!MyTreeView.Focused))
e.Node.ForeColor = Color.Blue;
else
e.DrawDefault = true;
And in the BeforeSelect event have:
if (MyTreeView.SelectedNode != null)
MyTreeView.SelectedNode.ForeColor = Color.Black;
e.Node.ForeColor = Color.Blue;
I don't know if it helps you or not but check the taborder of the the page and make sure that the tree view control has tab order of 0
Here is what I got to work:
void myProcedure()
{
// Hookup a DrawMode Event Handler
this.myTV.DrawNode += myTV_DrawNode;
// Set DrawMode and HideSelection
this.myTV.DrawMode = TreeViewDrawMode.OwnerDrawText;
this.myTV.HideSelection = false;
// Make sure the TreeView has Focus
this.myTV.Focus();
// Make sure the TreeView is Selected
this.myTV.Select();
// If the TreeView has a Node, I want to select the first Node to demonstrate.
if (this.myTV.Nodes.Count > 0)
{
// Make sure the node is visible
this.myTV.Nodes[0].EnsureVisible();
// Make sure the Node is Selected
this.myTV.SelectedNode = myTV.Nodes[0];
}
// Make sure the SelectedNode IS the Node that we programmatically want to select.
textBox1.Text = this.myTV.SelectedNode.Text;
// if we display sanityCheck1 string, it actually is the correct node.text
// Make sure .NET runtime knows the Node is selected
textBox1.Text += " is Selected = " + this.myTV.SelectedNode.IsSelected.ToString();
}
Following up: laalto answered the How to HighLight the TreeView.Node. The following code in the DrawNode Event Handler, from samball's answer, properly highlights the TreeView.Node based on its Selected State.
private void myTV_DrawNode(object sender, DrawTreeNodeEventArgs e)
{
// first, let .NET draw the Node with its defaults
e.DrawDefault = true;
// Now update the highlighting or not
if (e.State == TreeNodeStates.Selected)
{
e.Node.BackColor = SystemColors.Highlight;
e.Node.ForeColor = SystemColors.HighlightText;
}
else
{
e.Node.BackColor = ((TreeView)sender).BackColor;
e.Node.ForeColor = ((TreeView)sender).ForeColor;
}
}
Platform = C# .NET 4.5 in Windows 10, Visual Studio 2015
TreeView1.SelectedNode = TreeView1.Nodes(2);
this.ActiveControl = TreeView1;
This works for me (.net 4.7)
The underlying Win32 control supports this (think it's TVIS_DROPHILITED), but I can't see the same functionality exposed through the TreeView control.
As theraneman says, you could fake it with the TreeNode.ForeColor and BackColor properties...
I had an similar issue and wanted to have a TreeView node selected (highlighted) on form load.
Maybe someone has the same problem, too.
I first tried Pondidum's solution. Without success.
But then I found the solution in another thread: Simply set the TabIndex of the TreeView to 0.
In that case you don't need to set the focus. Just choose the node that should be selected by using SelectedNode and set the TabIndex. That's it.
Not sure, but can you not change the background color of that node?
When I tried using the imagelist in treeview, the image index changes when treenode is clicked. I have no idea why it is happening. Can anyone help me?
Thanks in advance
You need to set both the ImageIndex and the SelectedImageIndex on the tree node.
'SelectedImageIndex's intent is to allow displaying a different image upon selection than what is set by the 'ImageIndex' for a particular node. To keep these two consistent it is necessary to set them to the same value. This can be done at design time or programmatically depending on your needs.
For example, if the images never change then it is as simple as setting them concurrently when a new node is added to the TreeView:
int myCurrentImageIndex = 0;
TreeNode node = myTreeView.Nodes.Add("new node!");
node.ImageIndex = node.SelectedImageIndex = myCurrentImageIndex;
However, if you do change the ImageIndex value for any reason after its initial creation (such as a response to some kind of user action), then you must also change the SelectedImageIndex as well. Otherwise, they will become inconsistent.
int myNewImageIndex = 1;
node.ImageIndex = node.SelectedImageIndex = myNewImageIndex;
(Note it is not enough to set them to be the same in the event handler of the 'AfterSelect' event. It must be done anywhere in your code where ImageIndex changes.)
you can directly do it in the constructor :
TreeNode node = new TreeNode("My treenode", 1, 1);
TreeNode tn = new TreeNode();
tn.Text = "NewRecord";
tn.ImageIndex = 1;
treeView.SelectedNode.Nodes.Add(tn);
treeView.SelectedNode = tn;
treeView.SelectedNode.SelectedImageIndex = tn.ImageIndex; // <--- Problem solved
tn.BeginEdit();
Just Add this line:
Node.SelectedIndex:=Node.ImageIndex;