我正在按照这个教程进行学习：https://learn.microsoft.com/en-us/aspnet/core/tutorials/first-mvc-app/working-with-sql?view=aspnetcore-3.0&tabs=visual-studio，但是出现了以下错误信息：
"The Name Host does not exist in the current context"
下面是我的Program.cs文件内容。
下面是我的Program.cs文件内容。
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using MvcMovie.Data;
using MvcMovie.Models;
using System;
namespace MvcMovie
{
public class Program
{
public static void Main(string[] args)
{
var host = CreateHostBuilder(args).Build();
using (var scope = host.Services.CreateScope())
{
var services = scope.ServiceProvider;
try
{
SeedData.Initialize(services);
}
catch (Exception ex)
{
var logger = services.GetRequiredService<ILogger<Program>>();
logger.LogError(ex, "An error occurred seeding the DB.");
}
}
host.Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
}
}
Host.CreateDefaultBuilder(args) 下面有一条红线。