WebDataTree1.EnableConnectorLines = true
WebDataTree™ provides the option of having connector lines that are drawn between the nodes that are siblings of the same parent. This can be achieved by setting the WebDataTree control’s EnableConnectorLines property. By default, this property is set to False. However setting this property to True results in considerably more mark-up being emitted to the client to account for the images that are used to draw the connecting lines.
You can set the EnableConnectorLines property either using the Microsoft® Visual Studio® Property Window or by using the following code:
In Visual Basic:
WebDataTree1.EnableConnectorLines = true
In C#:
WebDataTree1.EnableConnectorLines = true;