private void CreateColumnAdorners() { if (Columns > 1) { var column = (int)GridSplitter.GetValue(Grid.ColumnProperty); // not all cases var leftColumn = GridSplitter.ResizeBehavior == GridResizeBehavior.PreviousAndNext ? column - 1 : column; var rightColumn = GridSplitter.ResizeBehavior == GridResizeBehavior.PreviousAndCurrent ? column : column + 1; var root = GridElement.FindRoot(); _adorners = new[] { new GridColumnWidthAdorner(root, GridElement, ColumnDefinitions[leftColumn], -50), new GridColumnWidthAdorner(root, GridElement, ColumnDefinitions[rightColumn], +30) }; } }