HighLight BackgroundColor UIButton on TouchUpInside is fired in MonoTouch

using System; using System.Drawing; using System.IO; using System.Text; using MonoTouch; using MonoTouch.UIKit; using MonoTouch.CoreGraphics; using MonoTouch.ObjCRuntime; namespace DicomViewerApplication { public static class SwapUIButtonColor { #region field private static UIButton _previousButton; private static UIButton _currentButton; #endregion #region prop public static UIButton PreviousButton { get { return _previousButton; } set { _previousButton = value; } } public static UIButton CurrentButton { get { return _currentButton; } set { _currentButton = value; } } #endregion #region SwapColor() highlight the button on click public static bool SwapColor (UIButton sender, bool isPrevBakGraound) { if (isPrevBakGraound == false) { InitApplyColorBorder (sender); SwapUIButtonColor.PreviousButton = sender; return true; } else { if (SwapUIButtonColor.PreviousButton != sender) { InitApplyColorBorder (sender); SwapUIButtonColor.CurrentButton = PreviousButton; PreviousButton = sender; SwapUIButtonColor.CurrentButton.Layer.BorderColor = (UIColor.Black).CGColor; SwapUIButtonColor.CurrentButton.Layer.BorderWidth = 0f; SwapUIButtonColor.CurrentButton.Layer.CornerRadius = 0f; return true; } else if (SwapUIButtonColor.PreviousButton == sender) { InitApplyColorBorder (sender); SwapUIButtonColor.PreviousButton = sender; return true ; } return true ; } } #endregion static void InitApplyColorBorder (UIButton sender) { sender.Layer.BorderColor = (UIColor.Red).CGColor; sender.Layer.BorderWidth = 1.0f; sender.Layer.CornerRadius = 10f; } } }

private UIButton btnBrightness btnBrightness = UIButton.FromType (UIButtonType.RoundedRect); btnBrightness.Frame = new RectangleF (540, 20, 95, 37); btnBrightness.SetTitle ("Brightness", UIControlState.Normal); ---- btnBrightness.TouchUpInside += (sender, e) => { //ImgView.Hidden = false; WindowLevelingTool.OnBrightClick (ImgView); isPrevBakGraound = SwapUIButtonColor.SwapColor (btnBrightness, isPrevBakGraound); };