Question

我有一个Xamarin项目，我已经工作了很长一段时间。但是当我打开它时，主界面突然变成空白。在iOS模拟器和我的iOS设备上。

应用构建时没有错误。我得到了我的闪屏，然后只是一个白色的空白屏幕。

我在Visual Studio 15中使用Xamarin与MVVMCross和故事板。

我尝试了以下内容：

重置iOS模拟器
Visual Studio中的清理解决方案
尝试将另一个故事板作为主界面

有什么想法吗？

编辑：这是我的AppDelegate.cs文件：

using Foundation;
using MvvmCross.Core.ViewModels;
using MvvmCross.iOS.Platform;
using MvvmCross.Platform;
using UIKit;
using Tjenester.Touch.Util;

namespace Tjenester.Touch
{
    [Register("AppDelegate")]
    public partial class AppDelegate : MvxApplicationDelegate
    {
        UIWindow _window;

        public override bool FinishedLaunching(UIApplication app, NSDictionary options)
        {
            _window = new UIWindow(UIScreen.MainScreen.Bounds);
            var setup = new Setup(this, _window);
            setup.Initialize();

            var startup = Mvx.Resolve<IMvxAppStart>();
            startup.Start();

            _window.MakeKeyAndVisible();

            MessageService.Initialize(this);

            return true;
        }
    }
}

这是我的CustomAppStart.cs：

using System;
using System.Threading.Tasks;
using Tjenester.Core.Helpers;
using Tjenester.Core.Services.Authentication;
using Tjenester.Core.ViewModels;
using Tjenester.Core.ViewModels.ViewModelParameters;
using Xamarin.Auth;
using Tjenester.Core;
using System.Threading;
using MvvmCross.Core.ViewModels;

/// <summary>
/// Custom Application start procedure to be fed to MvvmCross.
/// If we already have Username and Password, try login and proceed to the page.
/// TODO refactor when azure and google are added
/// </summary>
public class CustomAppStart : MvxNavigatingObject, IMvxAppStart
{

    public void Start(object hint = null)
    {
        ShowViewModel<LoginViewModel>(new LoginPageParameters() {TryLogin = true});
    }
}

这是我的Setup.cs：

using UIKit;
using Tjenester.Core.Helpers;
using Foundation;
using Tjenester.Core.Services.Media;
using Tjenester.Touch.Services;
using Tjenester.Core.Services.Storage;
using Tjenester.Core.Services.Scripting;
using Tjenester.Core;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using Tjenester.Core.Services.Http;
using MvvmCross.Core.ViewModels;
using MvvmCross.iOS.Platform;
using MvvmCross.Localization;
using MvvmCross.Platform;
using MvvmCross.Platform.Platform;
using MvvmCross.Platform.Plugins;
using Tjenester.Touch.Services.Http;
using Tjenester.Touch.Services.Storage;

namespace Tjenester.Touch
{
    public class Setup : MvxIosSetup
    {
        private readonly UIWindow _win;
        private readonly MvxApplicationDelegate _del;

        public Setup(MvxApplicationDelegate applicationDelegate, UIWindow window)
            : base(applicationDelegate, window)
        {
            _del = applicationDelegate;
            _win = window;
        }

        protected override IMvxApplication CreateApp()
        {
            UIContext.SynchronizationContext = SynchronizationContext.Current;
            if (NSLocale.PreferredLanguages.Length > 0) {
                var pref = NSLocale.PreferredLanguages [0];
                Settings.Language = pref.Substring (0, 2);
            }
            //Mvx.LazyConstructAndRegisterSingleton<IFileUploadService, TouchFileUploadService>();
            Mvx.LazyConstructAndRegisterSingleton<IHttpClientFactory, HttpClientFactory>();
            Mvx.LazyConstructAndRegisterSingleton<IStorageService, StorageService>();
            Mvx.LazyConstructAndRegisterSingleton<IPicturePickerService, TouchPicturePickerService>();
            return new Core.App();
        }

        protected override IEnumerable<System.Reflection.Assembly> ValueConverterAssemblies
        {
            get
            {
                var toReturn = base.ValueConverterAssemblies.ToList();
                toReturn.Add(typeof(MvxLanguageConverter).Assembly);
                return toReturn;
            }
        }

        protected override IMvxPluginConfiguration GetPluginConfiguration(Type plugin)
        {
            if (plugin == typeof(Tjenester.Core.Services.Scripting.PluginLoader))
            {
                return new MvxScriptServiceConfiguration()
                    .UseDefaultScriptBindings()
                ;
            }
            return base.GetPluginConfiguration(plugin);
        }

        protected override IMvxTrace CreateDebugTrace()
        {
            return new MvxDebugTrace();
        }
    }
}

Answer 1

您是否可以尝试手动初始化MvxIosViewPresenter以获取更多信息？

因此，您必须使用以下行（ApplicationDelegate.cs）：

_window = new UIWindow(UIScreen.MainScreen.Bounds);
var presenter = new MvxIosViewPresenter(this, _window);

var setup = new Setup(this, presenter);
setup.Initialize();

var startup = Mvx.Resolve<IMvxAppStart>();
startup.Start();

var rootViewController = new FirstView(); // You need to have created this ViewController
_window.RootViewController = rootViewController;

_window.MakeKeyAndVisible();

return true;

如果这适合您，那么这意味着您的故事板尚未正确创建。在故事板上设计的FirstViewController不知道实现MvxViewController的类FirstViewViewController的“Code”版本。

想要那个bash，看看它是怎么回事？这不是一个优雅的解决方案，但可以提供一些见解。

iOS上的空白屏幕

1 个答案: