mono touch中去掉NavigationBar的底部阴影

一句话搞定：

this.NavigationController.NavigationBar.Layer.MasksToBounds = true;

它很有效的，一般在做全屏界面的时候，如果你隐藏掉了NavigationBar的话，从没有隐藏的界面切换回来时，

界面顶部会有一块黑色的部分出现，虽然出现的时间很短，但给用户的体验很是不好，配合MasksToBounds属性，

我们给NavigationBar.SetBackgroundImage（。。。）设置一个图片，然后隐藏底部阴影，效果会很好，切诸多问

题都能解决.

/// <summary>/// Is called when the view is about to appear on the screen. We use this method to hide the /// navigation bar./// </summary>public override void ViewWillAppear (bool animated){base.ViewWillAppear (animated);this.NavigationController.SetNavigationBarHidden (true, animated);}/// <summary>/// Is called when the another view will appear and this one will be hidden. We use this method/// to show the navigation bar again./// </summary>public override void ViewWillDisappear (bool animated){base.ViewWillDisappear (animated);this.NavigationController.SetNavigationBarHidden (false, animated);}