Question

我正在尝试使用MVVX创建移动应用程序。尝试运行Droid应用程序时得到以下错误。

MvvmCross.Platform.Exceptions.MvxException：无法从定位器MvxDefaultViewModelLocator为类型ThoughtOfTheDay.ViewModels.LoginViewModel构造和初始化ViewModel - 检查InnerException以获取更多信息

以下是内部异常的详细信息。 MvvmCross.Platform.Exceptions.MvxException：无法从定位器MvxDefaultViewModelLocator构造和初始化类型ThoughtOfTheDay.ViewModels.LoginViewModel的ViewModel - 检查InnerException以获取更多信息---＆gt; MvvmCross.Platform.Exceptions.MvxException：创建LoginViewModel类型的viewModel时出现问题---＆gt; MvvmCross.Platform.Exceptions.MvxIoCResolveException：创建ThoughtOfTheDay.ViewModels.LoginViewModel 时无法解析IMvxMessenger类型的参数信使的参数在MvvmCross.Platform.IoC.MvxSimpleIoCContainer.GetIoCParameterValues（System.Type类型，System.Reflection.ConstructorInfo firstConstructor）[0x00036]在D：\ git \ MvvmCross \ MvvmCross \ Platform \ Platform \ IoC \ MvxSimpleIoCContainer.cs：504 在MvvmCross.Platform.IoC.MvxSimpleIoCContainer.IoCConstruct（System.Type类型）[0x0002a]在D：\ git \ MvvmCross \ MvvmCross \ Platform \ Platform \ IoC \ MvxSimpleIoCContainer.cs：314 在D：\ git \ MvvmCross \ MvvmCross \ Platform \ Platform \ Mvx.cs中的MvvmCross.Platform.Mvx.IocConstruct（System.Type t）[0x00005]：170 在MvvmCross.Core.ViewModels.MvxDefaultViewModelLocator.Load（System.Type viewModelType，MvvmCross.Core.ViewModels.IMvxBundle parameterValues，MvvmCross.Core.ViewModels.IMvxBundle savedState）[0x00000] in＆lt; 69bce0378e8e413982d3b552d7e387a8＆gt;：0 ---内部异常堆栈跟踪结束--- 在MvvmCross.Core.ViewModels.MvxDefaultViewModelLocator.Load（System.Type viewModelType，MvvmCross.Core.ViewModels.IMvxBundle parameterValues，MvvmCross.Core.ViewModels.IMvxBundle savedState）[0x00027] in＆lt; 69bce0378e8e413982d3b552d7e387a8＆gt;：0 在MvvmCross.Core.ViewModels.MvxViewModelLoader.LoadViewModel（MvvmCross.Core.ViewModels.MvxViewModelRequest请求，MvvmCross.Core.ViewModels.IMvxBundle savedState，MvvmCross.Core.ViewModels.IMvxViewModelLocator viewModelLocator）[0x00015]在＆LT; 69bce0378e8e413982d3b552d7e387a8＆GT;：0 ---内部异常堆栈跟踪结束--- 在MvvmCross.Core.ViewModels.MvxViewModelLoader.LoadViewModel（MvvmCross.Core.ViewModels.MvxViewModelRequest请求，MvvmCross.Core.ViewModels.IMvxBundle savedState，MvvmCross.Core.ViewModels.IMvxViewModelLocator viewModelLocator）[0x00046]在＆LT; 69bce0378e8e413982d3b552d7e387a8＆GT;：0 在MvvmCross.Core.ViewModels.MvxViewModelLoader.LoadViewModel（MvvmCross.Core.ViewModels.MvxViewModelRequest请求，MvvmCross.Core.ViewModels.IMvxBundle savedState）[0x00020] in＆lt; 69bce0378e8e413982d3b552d7e387a8＆gt;：0 在MvvmCross.Droid.Views.MvxAndroidViewsContainer.ViewModelFromRequest（MvvmCross.Core.ViewModels.MvxViewModelRequest viewModelRequest，MvvmCross.Core.ViewModels.IMvxBundle savedState）[0x00005] in：0 在MvvmCross.Droid.Views.MvxAndroidViewsContainer.CreateViewModelFromIntent（Android.Content.Intent intent，MvvmCross.Core.ViewModels.IMvxBundle savedState）[0x00027] in：0 在MvvmCross.Droid.Views.MvxAndroidViewsContainer.Load（Android.Content.Intent intent，MvvmCross.Core.ViewModels.IMvxBundle savedState，System.Type viewModelTypeHint）[0x00089] in：0 在MvvmCross.Droid.Views.MvxActivityViewExtensions.LoadViewModel（MvvmCross.Droid.Views.IMvxAndroidView androidView，MvvmCross.Core.ViewModels.IMvxBundle savedState）[0x0006a] in：0 在MvvmCross.Droid.Views.MvxActivityViewExtensions +＆lt;＆gt; c__DisplayClass1_0.b__1（）[0x0000a] in：0 在MvvmCross.Core.Views.MvxViewExtensionMethods.OnViewCreate（MvvmCross.Core.Views.IMvxView视图，System.Func 1[TResult] viewModelLoader) [0x00012] in <69bce0378e8e413982d3b552d7e387a8>:0 at MvvmCross.Droid.Views.MvxActivityViewExtensions.OnViewCreate (MvvmCross.Droid.Views.IMvxAndroidView androidView, Android.OS.Bundle bundle) [0x00062] in <f6aebf863dc84be7b380cfec8d459508>:0 at MvvmCross.Droid.Views.MvxActivityAdapter.EventSourceOnCreateCalled (System.Object sender, MvvmCross.Platform.Core.MvxValueEventArgs 1 [T] eventArgs）[0x0000c] in：0 at（wrapper delegate-invoke）System.EventHandler 1[MvvmCross.Platform.Core.MvxValueEventArgs 1 [Android.OS.Bundle]]：invoke_void_object_TEventArgs（object，MvvmCross.Platform.Core.MvxValueEventArgs 1<Android.OS.Bundle>) at MvvmCross.Platform.Core.MvxDelegateExtensionMethods.Raise[T] (System.EventHandler 1 [TEventArgs] eventHandler，System.Object发送者，T值）[0x00000]在D：\ git \ MvvmCross \ MvvmCross \ Platform \ Platform \ Core \ MvxDelegateExtensionMethods.cs：21 在MvvmCross.Platform.Droid.Views.MvxEventSourceActivity.OnCreate（Android.OS.Bundle bundle）[0x00014] in＆lt; 4230cf00b647458f9b3e211590e6cc9d＆gt;：0 at ThoughtOfTheDay.Droid.Views.LoginView.OnCreate（Android.OS.Bundle bundle）[0x00002]在C：\ Work \ MobileDev \ ThoughtOfTheDay \ ThoughtOfTheDay \ ThoughtOfTheDay.Droid \ Views \ LoginView.cs：15

我正在尝试将IMvxMessenger传递给视图模型。上面的内部异常消息显示解决IMvxMessenger存在问题。我是否需要在app.cs \ Initialize（）中包含一些内容？如果您需要更多信息，请告诉我。非常感谢您的时间和帮助。

public LoginViewModel(IMvxMessenger messenger,
            IDialogService dialogService,
            IUserService userService)
            : base(messenger)
        {
            _userService = userService;
            _dialogService = dialogService;
        }

解决方案：安装了Android项目中MvvmCross.Plugin.Messenger的Nuget包。之前我只在PCL项目中安装了它。

Answer 1

解决方案：安装了Android项目中MvvmCross.Plugin.Messenger的Nuget包。之前我只在PCL项目中安装了它。

Answer 2

听起来你错过了插件的引导程序。

确保使用以下内容在Bootstrap文件夹中创建一个类：

using MvvmCross.Platform.Plugins;

namespace your.name.space.Bootstrap
{
    public class MessengerPluginBootstrap
        : MvxPluginBootstrapAction<MvvmCross.Plugins.Messenger.PluginLoader>
    {
    }
}

这将使用IoC容器注册插件。

或者，您可以在InitializeLastChance文件的Setup.cs中自行注册：

Mvx.RegisterSingleton<IMvxMessenger>(() => new MvxMessengerHub());

MVVX无法从MvxDefaultViewModelLocator

2 个答案: