A SplitPanel has the BorderStyle property just because it is a RadControl inheritor. However, this property is not relevant to the SplitPanel object. In order to hide the borders of a SplitPanel, please set the Visibility property of a SplitPanel's BorderPrimitive to Collapsed:
.splitPanel1.SplitPanelElement.Children).Visibility = Telerik.WinControls.ElementVisibility.Collapsed;
I hope this helps. If you have additional questions, feel free to contact me.
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