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;
Related
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;
Hey embarrassingly enough I ran into the error stated in the title. As many others have sought to find a solution online, but I was not able to do so.
Okay so my issue, is that I have an ObservableCollection of my elements which is used in an Itemscontrol. I want to create a new element of one of the elements in the ObservableCollection. Because of the trouble with working with ObservableCollection I created a serializing and Deserializing of the specific object. like this>
IsolatedStorage.SerializeSElement("saveString", saveElement);
IsolatedStorage.DeSerializeSElement("saveString", loadElement);
Which I than hoped gave me a completely new element. But I still have the same element. How do I solve the issue if say my class looks like>
public class myElement(){
int posx;
int posy;
double id;
bool isMoveable;
}
But there is still the error, is there way to solve this error?
Code
private Geometry createGeometry(SViewModel sModelRec)
{//TEST
sModel = sModelRec.Gear;
sModelRec = null;
//new Path.Combine(DecorationOnShield[i].Gear.Path,"");
PathGeometry pathGeometry = new PathGeometry();
PathFigure testPathFigure = new PathFigure();
System.Windows.Shapes.Path pathTesting = new System.Windows.Shapes.Path();
var b = new System.Windows.Data.Binding
{
Source = sModel.Path
};
System.Windows.Data.BindingOperations.SetBinding(pathTesting, System.Windows.Shapes.Path.DataProperty, b);
pathTesting.Width = sModel.Width;
pathTesting.Height = sModel.Height;
Geometry geometry = pathTesting.Data;
return geometry;
}
So when I return the element and add it to the GeometryGroup I get the error.
You are trying to Add a Control and that Control already exists in your VisualTree.
The solution is simple
You have Source Parent Container = The control in witch resides the element you want to add to the other container
Target Parent Container = The control in witch you want to add your element.
To solve your problem just remove the element from the Source Parent Container and then add it to your Target Parent Container
Note: to have an answer more specific to your situation you must post your view or the lines where the error is getting thrown
At the moment I have a hardcoded treeview in a winform set up with the following code:
private void Form1_Load_1(object sender, EventArgs e)
{
TreeNode _leftCameraNode = new TreeNode("LeftCamera");
TreeNode _rightCameraNode = new TreeNode("RightCamera");
TreeNode[] stereoCameraArray = new TreeNode[] { _leftCameraNode, _rightCameraNode };
TreeNode _screenNode = new TreeNode("Screen");
TreeNode _cameraNode = new TreeNode("Camera", stereoCameraArray);
TreeNode[] headNodeArray = new TreeNode[] { _cameraNode };
TreeNode _headNode = new TreeNode("HeadNode", headNodeArray);
TreeNode[] centreNodeArray = new TreeNode[] { _screenNode, _headNode };
TreeNode _centreNode = new TreeNode("CentreNode", centreNodeArray);
// root node
TreeNode[] inmoRootNodeArray = new TreeNode[] { _centreNode };
TreeNode treeNode = new TreeNode("Main Node", inmoRootNodeArray);
treeView1.Nodes.Add(treeNode);
}
This works fine, however it is very limiting in its functionality. What I really want this to do is be populated from a list of nodes that I've set up and filled out with information that I'm getting from a bunch of text boxes on my form.
For example, I create a new list of screens (child of my node class) like so:
public List<HV_Screen> _screenList = new List<HV_Screen>();
Then I fill out my list with the data entered from my text box like this:
if (_selectedNode > -1)
{
Node n = _nodeList[_nodeList.Count - 1];
n.Name = _screenName;
}
I've been looking around on the net and on stackoverflow but I can't find anything to help me out with dynamically creating my treeview, so I was wondering if anyone would be able to point me in the right direction and help me out in how to do this?
The reason I want to do this is because, say I have 3 different instances of my screen, I want my treeview to show this, Then if I change the name in screen1 to MYSCREEN, I want my treeview to show this. But, should I click screen2, the treeview will still show the default name. Then, when I click back on screen1, its new name MYSCREEN will still be there on display.
I hope that makes sence.
Edit
Following on from a comment here is a screenshot of my current GUI:
The tree structure there has all be hard coded in with the code above. This takes in no information from my class screen class.
Now, my HV_Screen class looks as follows:
private string WIDTH;
private string HEIGHT;
public string Width
{
get { return WIDTH; }
set { WIDTH = value; }
}
public string Height
{
get { return HEIGHT; }
set { HEIGHT = value; }
}
public override List<XmlElement> GenerateXML(XmlDocument _xmlDoc)
{
List<XmlElement> elementList = new List<XmlElement>();
XmlElement _screenName = _xmlDoc.CreateElement("ScreenName");
_screenName.SetAttribute("Name", name.ToString());
_screenName.InnerText = name.ToString();
elementList.Add(_screenName);
XmlElement _screenTag = _xmlDoc.CreateElement("ScreenTag");
_screenTag.SetAttribute("Tag", tag.ToString());
_screenTag.InnerText = tag.ToString();
elementList.Add(_screenTag);
XmlElement _localPosition = _xmlDoc.CreateElement("LocalPosition");
_localPosition.SetAttribute("X", XPOS.ToString());
_localPosition.SetAttribute("Y", YPOS.ToString());
_localPosition.SetAttribute("Z", ZPOS.ToString());
_localPosition.InnerText = WorldPos.ToString();
elementList.Add(_localPosition);
XmlElement _orientation = _xmlDoc.CreateElement("Orientation");
_orientation.SetAttribute("Yaw", YAW.ToString());
_orientation.SetAttribute("Pitch", PITCH.ToString());
_orientation.SetAttribute("Roll", ROLL.ToString());
_orientation.InnerText = Orientation.ToString();
elementList.Add(_orientation);
XmlElement _width = _xmlDoc.CreateElement("Width");
_width.SetAttribute("Width", WIDTH.ToString());
_width.InnerText = WIDTH.ToString();
elementList.Add(_width);
XmlElement _height = _xmlDoc.CreateElement("Height");
_height.SetAttribute("Height", HEIGHT.ToString());
_height.InnerText = HEIGHT.ToString();
elementList.Add(_height);
return elementList;
}
Nothing too major. This simply takes in the information and writes it to an xml file. I plan on doing this for each of my Node children. So, if I was to have a camera class, it would have its own generate XML function and write it out from there. My base class (node) simply has a bunch of getters and setters for things like name, tag etc.
With the way the code is set up at the moment, I can add in new nodes. First I must select the root node I want to branch from, then I fill out the information associated with it. So in that screen shot, if I was to select Main Node and then hit the Add button, Sample Name would now be a child of Main Node. However, if I was to select Sample and Name and change it, nothing would happen.
This way is also hard coded in to only relate to my screen class. In theory, I could simply turn a lot of different text boxes on and off but this would be really bad practise. And I'm pretty sure it will have an impact on my programs performance.
So again, what I want is one Name text box that will be in charge of filling out the name for every object that requires a name. Then, I wish to take the name I entered and have it fill out the treeview. Once I select it, I want my selected node to fill out the textboxes with all of the associated text I put in for it. But, should I change the name of my selected node, it will also change the name in the tree structure.
Again, sorry if that is confusing. I'm pretty beat at the moment.
So in my project i would like have a nice treeview that has images.
but when i run the program the image was not shown. Any idea?
here is my code:
while (thisreader.Read()) // i read from the database.
{
TreeNode tn = new TreeNode();
tn.Text = thisreader["channel_name"].ToString();
tn.ImageIndex = 1;
tn.SelectedImageIndex = 1; // i have my imagelist1 in the corresponding winform
treeView1.Nodes.Add(tn);
}
The ImageList must be assigned to the ImageList property of the TreeView as well. Simply dropping it on the form is not enough.
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?