Question

我需要创建一个简单的应用程序，其中MainViewModel在初始化期间发生了某些事情。

当我尝试运行我的代码时，异常发生在DisplayRootViewFor<MainViewModel>();的{{1}}行：

mscorlib.dll中发生了'System.MissingMethodException'类型的异常但未在用户代码中处理

附加信息：没有为此对象定义无参数构造函数。

引导程序：

AppBootstrapper

MainViewModel：

using System;
using Ninject;
using Caliburn.Micro;

namespace ChartsDisplayer2016
{ 
    public class AppBootstrapper : BootstrapperBase
    {
        private IKernel kernel;
        public AppBootstrapper()
        {
            Initialize();
        }

        protected override void Configure()
        {
            kernel = new StandardKernel();
            kernel.Load(AppDomain.CurrentDomain.GetAssemblies());
            kernel.Bind<IEventAggregator>().To<EventAggregator>().InSingletonScope();
        }
        protected override void BuildUp(object instance)
        {
            kernel.Inject(instance);
        }
        protected override void OnStartup(object sender, System.Windows.StartupEventArgs e)
        {
            base.OnStartup(sender, e);
            DisplayRootViewFor<MainViewModel>();
        }
    }
}

的MainView：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ChartsDisplayer2016.Core.Charts.ViewModels;
using Caliburn.Micro;

namespace ChartsDisplayer2016.Core.Main.ViewModels
{
    public class MainViewModel: Conductor<Screen>.Collection.OneActive
    {
        private readonly IEventAggregator eventAggregator;
        private readonly IWindowManager windowManager;

        MainViewModel()
        {
            //something important;
        }
        MainViewModel(IEventAggregator eventAggregator,
            IWindowManager windowManager)
        {
            this.eventAggregator = eventAggregator;
            this.eventAggregator.Subscribe(this);
            this.windowManager = windowManager;

            //something important
        }
    }
}

如何摆脱这种异常？

编辑：

将<UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" x:Class="ChartsDisplayer2016.Core.Main.Views.MainView" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300"> <Grid> </Grid> </UserControl>的访问修饰符更改为MainViewModel

Answer 1

您的MainViewModel类和构造函数没有访问说明符，因此默认为private。

    namespace ChartsDisplayer2016.Core.Main.ViewModels
    {

        public class MainViewModel: Conductor<Screen>.Collection.OneActive
        {

            private readonly IEventAggregator eventAggregator;
            private readonly IWindowManager windowManager;


            public MainViewModel()
            {
                //something important;
            }
            public MainViewModel(IEventAggregator eventAggregator,
                                 IWindowManager windowManager)
            {
                this.eventAggregator = eventAggregator;
                this.eventAggregator.Subscribe(this);
                this.windowManager = windowManager;

                //something important
            }
        }
    }

Bootstrapper DisplayRootFor <mv>（）异常：无参数构造函数

1 个答案: