如何更改xamarin.forms ios上的导航栏标题图标？

Question

我想在我的xamarin.forms ios应用程序中更改导航栏标题图标。您可以在附加的图像中找到请求的点。app_screenshot

Answer 1

查看更改后退按钮：https://developer.xamarin.com/recipes/ios/content_controls/navigation_controller/change_the_back_button/

Answer 2

您可以在Xamarin.Forms上使用Custom Renderers来实现此目的。由于每个UIViewController都有自己的NavigationItem，因此您应该在要修改其LeftBarButtonItem的特定页面中执行此操作。以下是我的渲染器：

[assembly: ExportRenderer(typeof(CustomPage), typeof(CustomPageRenderer))]
namespace UIBarButtomItemsForms.iOS
{
    public class CustomPageRenderer : PageRenderer
    {
        protected override void OnElementChanged(VisualElementChangedEventArgs e)
        {
            base.OnElementChanged(e);


        }

        public override void ViewWillAppear(bool animated)
        {
            base.ViewWillAppear(animated);

            var navigationItem = NavigationController.TopViewController.NavigationItem;

            UIBarButtonItem leftItem = new UIBarButtonItem(UIImage.FromBundle("Image.png"), UIBarButtonItemStyle.Plain, (sender, args) =>
            {

            });

            navigationItem.SetLeftBarButtonItem(leftItem, false);
        }
    }
}

然后在表单上，​​您可以使用此CustomPage，请注意您应该将MainPage包裹在NavigationPage中：MainPage = new NavigationPage(new MainPage());