Flip via the UI
You can use the rotate buttons to directly rotate the image. No dialog is shown in this case.
Flip Programmatically
The following spinet shows how you can access and use the RotateFlip method.
Flip programmatically
radImageEditor1.ImageEditorElement.RotateFlip(RotateFlipType.RotateNoneFlipX);
radImageEditor1.ImageEditorElement.SaveState();
radImageEditor1.ImageEditorElement.RotateFlip(RotateFlipType.RotateNoneFlipX)
radImageEditor1.ImageEditorElement.SaveState()