How to set the images for treeview nodes in the WinForms TreeView?
WinForms TreeView control can be customized with images to the Left or Right side of its TreeNodeAdv. The images can be set on the Left or Right by using the properties LeftImageList and RightImageList. It is also possible to specify different images for the individual nodes by using the LeftImageIndices and RightImageIndices properties in the TreeNodeAdv.
C#
//Assigns image list to the TreeNodeAdv.
this.treeViewAdv1.LeftImageList = this.imageList1;
this.treeViewAdv1.RightImageList = this.imageList1;
//Gets the Path of the node and AddSeparatorAtEnd property set to true.
string path = e.Node.GetPath("\\");
//Gets an Array of Directories from the current directory path.
ArrayList dirs = new ArrayList(Directory.GetDirectories(path));
//Adds the Directories as a node in the TreeViewAdv
for (int i = 0; i < dirs.Count; i++)
{
string dir = (string)dirs[i];
int lastIndex = dir.LastIndexOf("\\") + 1;
TreeNodeAdv node = new TreeNodeAdv(dir.Substring(lastIndex));
e.Node.Nodes.Add(node);
node.RightImageIndices = new int[] { 1 };
}
//Sets the Left images for the TreeNodeAdv.
foreach (TreeNodeAdv node in this.treeViewAdv1.Nodes[0].Nodes)
{
node.LeftImageIndices = new int[] { 1 };
node.RightImageIndices = new int[] { -1 };
}
//Sets the Right images for the TreeNodeAdv.
foreach (TreeNodeAdv node in this.treeViewAdv1.Nodes[0].Nodes)
{
node.RightImageIndices = new int[] { 1 };
node.LeftImageIndices = new int[] { -1 };
}
VB
'Assigns image list to the TreeNodeAdv.
Me.treeViewAdv1.LeftImageList = Me.imageList1
Me.treeViewAdv1.RightImageList = Me.imageList1
'Gets the Path of the node and AddSeparatorAtEnd property set to true.
Dim path As String = e.Node.GetPath("\")
'Gets an Array of Directories from the current directory path.
Dim dirs As New ArrayList(Directory.GetDirectories(path))
'Adds the Directories as a node in the TreeViewAdv.
For i As Integer = 0 To dirs.Count - 1
Dim dir As String = CStr(dirs(i))
Dim lastIndex As Integer = dir.LastIndexOf("\") + 1
Dim node As New TreeNodeAdv(dir.Substring(lastIndex))
e.Node.Nodes.Add(node)
node.RightImageIndices = New Integer() { 1 }
Next i
'Sets the Left images for the TreeNodeAdv.
For Each node As TreeNodeAdv In Me.treeViewAdv1.Nodes(0).Nodes
node.LeftImageIndices = New Integer() { 1 }
node.RightImageIndices = New Integer() { -1 }
Next node
'Sets the Right images for the TreeNodeAdv.
For Each node As TreeNodeAdv In Me.treeViewAdv1.Nodes(0).Nodes
node.RightImageIndices = New Integer() { 1 }
node.LeftImageIndices = New Integer() { -1 }
Next node
Figure 1: Images aligned on the left side of the TreeNodeAdv
Figure 2: Images aligned right side of the TreeNodeAdv
Reference link: https://help.syncfusion.com/windowsforms/treeview/treenodeadvcustomization#image-customization.
Conclusion.
I hope you enjoyed learning about how to set the images for treeview nodes in the WinForms TreeView. You can explore runnable sample of set the images for treeview nodes from this GitHub location.
You can refer to our WinForms TreeView feature tour page to know about its other groundbreaking feature representations. You can also explore our WinForms TreeView example to understand how to present and manipulate data.
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