TreeView Controls and Images

[Andy @ Corero]

Hi

Is there a way you can specify the images for a TreeView control from embedded resources?

Obviously for an image, this is a simple case of

<nameofcontrol>.Image = <wherever>.Resources.<image name>

in the UI.cs file constructor

Now for a treeview, despite the image being a simple bmp file, you need to set

<nameofcontrol>.ImageList (I'd guess) = ????

(just entering the bmp gives a type mismatch)

(At the moment we are defining the ImageListLocation to be %WorkingDir%Images\<nameofimage>.bmp

which works, but are looking to embed all our remaining images to within a dll)

Thanks

Andy

[Sefi Bar-El]

Hi Andy,

You can set an image list and add images for the Collapsed and Expanded states of the tree nodes.

Here is a code sample (I've added 2 images named Folder and FolderOpen to the project resources):

namespace Northwind.Demo.Views
{
    // This is the code behind of the form
    partial class TreeViewDemoView : Shared.Theme.Controls.Form
    {
        TreeViewDemo _controller;
        public TreeViewDemoView(TreeViewDemo controller)
        {
            _controller = controller;
            InitializeComponent();
 
            
            treeView1.Data = new TreeViewData(_controller.categories.CategoryName);
 
            // adding embedded images to the treeview control
            var imageList = new ImageList();
            imageList.Images.Add(new Bitmap(Properties.Resources.Folder));
            imageList.Images.Add(new Bitmap(Properties.Resources.FolderOpen));
            treeView1.ImageList = imageList;
            treeView1.SelectedCollapsedImageIndex = 0;
            treeView1.SelectedExpandedImageIndex = 1;
        }
    }
}

[Andy @ Corero]

Thanks Sefi

I'll try this in due course.

I think there are 3 images though - expanded, collapsed and 'not applicable' (I'm certainly seeing 3 images and 3 states in the existing treeview.)

[Sefi Bar-El]

Hi Andy,

You can use expressions for the image indexes.

The Tree control has the following events:

• BindCollapsedImageIndex
  
• BindExpandedImageIndex
  
• BindSelectedCollapsedImageIndex
  
• BindSelectedExpandedImageIndex
  

You can set them using the Properties/Events sheet.

Here is a simple example of Binding the CollapsedImageIndex:

And the code of the event is:

private void treeView1_BindCollapsedImageIndex(object sender, IntBindingEventArgs e)
{
    if (_controller.Emps.TitleOfCourtesy == "Mr.")
        e.Value = 0;
    else if (_controller.Emps.TitleOfCourtesy == "Ms.")
        e.Value = 1;
    else
        e.Value = 2;
}

BTW, you can also drag an ImageList control from the ToolBox to the form and choose the images to embed from the context menu: