I have the strange problem that the column headers seem to over-paint the control border. It seems to be theme related as it does not happen if I use the default theme. Although I didn't have this issue in my prototype....
I have tested the different themes of RadGridView in the Demo application. It seems that the grid in the provided screenshot uses the Fluent theme. I have logged it in our feedback portal. You can track its progress, subscribe for status changes and add your comments on the following link - feedback item.
Currently, the possible solution that I can suggest is to apply 1 px top margin of the TableElement.
this.radGridView1.TableElement.Margin = new Padding(0, 1, 0, 0);
I hope this information helps.
Regards,
Dess
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