Hi David,
Thank you for using Syncfusion Products.
You can replace the default Group Expand and Collapse images by specifying new images to GroupExpandImage and GroupCollapseImage properties. Please refer any one of the code snippet from below.
[ASPX]
[C#]
protected void Page_Load(object sender, EventArgs e)
{
this.GridGroupingControl1.TableDescriptor.GroupCollapseImage = "images\\plus.gif";
this.GridGroupingControl1.TableDescriptor.GroupExpandImage = "images\\minus.gif";
}
Refer a simple sample to illustrate this.
http://files.syncfusion.com/support/GGC.Web/7.2.0.37/F86388/main.htmThanks,
Rekha