InvalidOperationException was unhandled by user code

An exception of type 'System.InvalidOperationException' occurred in Microsoft.AspNet.Mvc.Core.dll but was not handled in user code


Additional information: Unable to find the required services. Please add all the required services by calling 'IServiceCollection.AddMvc()' inside the call to 'IApplicationBuilder.ConfigureServices(...)' or 'IApplicationBuilder.UseMvc(...)' in the application startup code.

用户代码中存在未处理的无效操作异常

用户代码中存在没有处理的'System.InvalidOperationException'类型的异常出现在Microsoft.AspNet.Mvc.Core.dll中。

附加信息: 无法找到所需的服务。请添加所有必需的服务通过调用'IServiceCollection.AddMvc()'在'IApplicationBuilder.ConfigureServices(...)'内部

或'IApplicationBuilder.UseMvc(...)' 在应用程序启动代码中调用。

产生异常的文件为“setup.cs”，代码如下：

using Microsoft.AspNet.Builder;
using Microsoft.AspNet.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Framework.DependencyInjection;

public class Startup
{
    public void Configure(IApplicationBuilder app)
	{
		app.UseDefaultFiles();
		app.UseStaticFiles();

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });   
    }

    public static void Main(string[] args) => WebApplication.Run(args);
}

在app.UseMvc处出错了，能看懂错误提示中的附加信息的话，应该已经大概明白了怎么处理。

我们把出错的代码加个Try catch处理，得到具体的错误信息：

发现和上面给出的附加信息是一样的。

所以调试运行的时候产生未处理的异常，不要急着复制第一句错误信息“An exception of type 'System.InvalidOperationException' occurred in Microsoft.AspNet.Mvc.Core.dll but was not handled in user code”去搜索，对于类似 的错误这通常找到的答案都不是你想要的，因为这种类似的异常太多了。而应该去搜索附加信息Additional information: 后面的内容，那才是真实的错误信息。

那么上面的这个问题怎么解决呢？

啥也不说了，上代码：

using Microsoft.AspNet.Builder;
using Microsoft.AspNet.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Framework.DependencyInjection;

public class Startup
{
    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(Microsoft.Extensions.DependencyInjection.IServiceCollection services)
    {
        // Add framework services.
        services.AddMvc();
    }

    public void Configure(IApplicationBuilder app)
	{
		app.UseDefaultFiles();
		app.UseStaticFiles();

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });

    }

    public static void Main(string[] args) => WebApplication.Run(args);
}

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如果自己没有尽力，就没有资格批评别人不用心。开口抱怨很容易，但是闭嘴努力的人，更加值得尊敬。