Question

您好，我有一个应用程序我正在使用Xamrian iOS本机和Xamrian Forms中的一部分，我尝试做的就是当用户点击我本机应用程序中的contectbttn时它打开了来自CountySelect类的xamrian。我在应用程序崩溃后单击设备上的按钮时收到此错误：

System.InvalidOperationException: call Forms.Init() before this

这里是按下按钮的原生Xamrian iOS代码：

using System;
using UIKit;
using CoreGraphics;
using Xamarin.Forms;
namespace App.iOS
{
    public partial class HomeView : UIViewController
    {
        public HomeView(IntPtr handle) : base(handle)
        {

        }
        public override void ViewDidLoad()
        {
            base.ViewDidLoad();


            contactbttn.TouchUpInside += (sender, e) => {
                var secondViewController = App.GetSecondPage().CreateViewController();
                NavigationController.PushViewController(secondViewController, true);
            };
        }
    }
}

这是我的app.cs代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Xamarin.Forms;

namespace App
{
    public class App : Application
    {

        public static Page GetSecondPage()
        {
            var formsPage = new NavigationPage(new CountySelect());

            return formsPage;
        }
        public App()
        {
            // The root page of your application
            //MainPage = new MainPage();
            MainPage = new NavigationPage(new CountySelect());

        }



        protected override void OnStart()
        {
            // Handle when your app starts
        }

        public static object CountySelect()
        {
            throw new NotImplementedException();
        }

        protected override void OnSleep()
        {
            // Handle when your app sleeps
        }

        protected override void OnResume()
        {
            // Handle when your app resumes
        }
    }
}

编辑此处的AppDelegate代码：

using System;
using System.Collections.Generic;
using System.Linq;
using Foundation;
using UIKit;
using Xamarin.Forms;
using Foundation;
using UIKit;
using System.IO;
using Xamarin.Forms.Platform.iOS;

namespace App.iOS
{
    // The UIApplicationDelegate for the application. This class is responsible for launching the
    // User Interface of the application, as well as listening (and optionally responding) to
    // application events from iOS.
    [Register("AppDelegate")]
    public partial class AppDelegate : UIApplicationDelegate
    {
        // class-level declarations
        public override UIWindow Window
        {
            get;
            set;
        }
        // This method is invoked when the application is about to move from active to inactive state.
        // OpenGL applications should use this method to pause.
        public override void OnResignActivation(UIApplication application)
        {
        }
        // This method should be used to release shared resources and it should store the application state.
        // If your application supports background exection this method is called instead of WillTerminate
        // when the user quits.
        public override void DidEnterBackground(UIApplication application)
        {
        }
        // This method is called as part of the transiton from background to active state.
        public override void WillEnterForeground(UIApplication application)
        {
        }
        // This method is called when the application is about to terminate. Save data, if needed.
        public override void WillTerminate(UIApplication application)
        {
        }
        public override bool FinishedLaunching(UIApplication app, NSDictionary options)
        {
            Forms.Init();

            return true;
        }
    }
}

我不知道如何解决这个错误我试过谷歌搜索错误而没有运气：/

任何帮助都会很棒

提前致谢！

System.InvalidOperationException：在此Xamrian iOS Hybrid项目之前调用Forms.Init（）

0 个答案: