public UI.Size Measure(UI.Size constraints) { double width = passwordBox.Width; double height = passwordBox.Height; passwordBox.Width = double.NaN; passwordBox.Height = double.NaN; passwordBox.Measure(new System.Windows.Size(constraints.Width, constraints.Height)); passwordBox.Width = width; passwordBox.Height = height; return(new UI.Size(passwordBox.DesiredSize.Width, passwordBox.DesiredSize.Height)); }