没有注册“Microsoft.AspNetCore.Mvc.ViewFeatures.PartialViewResultExecutor”类型的服务

Question

I have a ToString() method for Partial Views.

My usings :

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.Extensions.DependencyInjection;
using System.IO;
using System.Threading.Tasks; 

public static class ViewExtensions
{
    public static async Task<string> ToString(this PartialViewResult partialView, ActionContext actionContext)
    {
        using (var writer = new StringWriter())
        {
            var services = actionContext.HttpContext.RequestServices;
            var executor = services.GetRequiredService<PartialViewResultExecutor>();
            var view = executor.FindView(actionContext, partialView).View;
            var viewContext = new ViewContext(actionContext, view, partialView.ViewData, partialView.TempData, writer, new HtmlHelperOptions());
            await view.RenderAsync(viewContext);
            return writer.ToString();
        }
    }
}

In ASP.NET Core 2.2 I am getting this error :

System.InvalidOperationException: No service for type 'Microsoft.AspNetCore.Mvc.ViewFeatures.PartialViewResultExecutor' has been registered. at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType) at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)

Answer 1

在Startup类的ConfigureServices方法中添加以下行：

services.AddSingleton<PartialViewResultExecutor>();