private async System.Threading.Tasks.Task UpdateToolbarItems()
        {
            await System.Threading.Tasks.Task.Delay(20);

            var contentPage = this.Element as ContentPage;

            if (contentPage == null || NavigationController == null)
            {
                return;
            }
            var itemsInfo = contentPage.ToolbarItems;

            var navigationItem = this.NavigationController.TopViewController.NavigationItem;

            var newLeftButtons = new UIBarButtonItem[] { }.ToList();
            var newRightButtons = new UIBarButtonItem[] { }.ToList();

            foreach (var item in itemsInfo)
            {
                if (item.Priority == 0)
                {
                    newLeftButtons.Add(item.ToUIBarButtonItem());
                }
                else
                {
                    newRightButtons.Add(item.ToUIBarButtonItem());
                }
            }

            navigationItem.RightBarButtonItems = newRightButtons.ToArray();
            navigationItem.LeftBarButtonItems  = newLeftButtons.ToArray();
        }
示例#2
0
        public override void ViewWillAppear(bool animated)
        {
            base.ViewWillAppear(animated);

            var contentPage = this.Element as ContentPage;

            if (contentPage == null || NavigationController == null)
            {
                return;
            }

            var itemsInfo = contentPage.ToolbarItems;

            var navigationItem     = this.NavigationController.TopViewController.NavigationItem;
            var leftNativeButtons  = (navigationItem.LeftBarButtonItems ?? new UIBarButtonItem[] { }).ToList();
            var rightNativeButtons = (navigationItem.RightBarButtonItems ?? new UIBarButtonItem[] { }).ToList();

            var newLeftButtons = new UIBarButtonItem[] { }.ToList();
            var newRightButtons = new UIBarButtonItem[] { }.ToList();

            rightNativeButtons.ForEach(nativeItem =>
            {
                // [Hack] Get Xamarin private field "item"
                var field = nativeItem.GetType().GetField("_item", BindingFlags.NonPublic | BindingFlags.Instance);
                if (field == null)
                {
                    return;
                }

                var info = field.GetValue(nativeItem) as ToolbarItem;
                if (info == null)
                {
                    return;
                }

                if (info.Priority == 0)
                {
                    newLeftButtons.Add(nativeItem);
                }
                else
                {
                    newRightButtons.Add(nativeItem);
                }
            });

            leftNativeButtons.ForEach(nativeItem =>
            {
                newLeftButtons.Add(nativeItem);
            });

            navigationItem.RightBarButtonItems = newRightButtons.ToArray();
            navigationItem.LeftBarButtonItems  = newLeftButtons.ToArray();
        }