By default, click and drag action on port will draw a new connection. This default behavior can be modified at runtime by using the SetTool() method of WPF Diagram (SfDiagram). C# public class CustomDiagram : SfDiagram { protected override void SetTool(SetToolArgs args) { if (args.Source is IPort) { args.Action = ActiveTool.Drag; } else { base.SetTool(args); } } } View sample in GitHub.