MVC控件器动作 返回类型 IActionResult

using Microsoft.AspNetCore.Mvc;
using System.Diagnostics;
using System.Text;
using TestMvcWebApplication.Models;

namespace TestMvcWebApplication.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public HomeController(ILogger<HomeController> logger)
        {
            _logger = logger;
        }

        public IActionResult Index()
        {
            Student student = new Student();
            student.Id = 1;
            student.Name = "Test";
            List<Student> students = new List<Student>();
            students.Add(student);
            student = new Student { Id = 2, Name = "张三" };
            students.Add(student);
            return View(students);
        }

        public IActionResult Privacy()
        {
            return View();
        }
        public IActionResult Test()
        {//重定向
            return RedirectToAction("Index");
        }
        public IActionResult ShowJson()
        {//返回Json数据,中文不进行编码
            List<Student> list = new List<Student>
            {
                new Student { Id=1,Name="张三" },
                new Student { Id=2,Name="李四"},
                new Student { Id=3,Name="王五"},
            };
            return Ok(list);
        }
        public IActionResult ShowJson2()
        {//返回Json数据,中文已编码
            List<Student> list = new List<Student>
            {
                new Student { Id=1,Name="张三" },
                new Student { Id=2,Name="李四"},
                new Student { Id=3,Name="王五"},
            };
            return Json(list);
        }
        public IActionResult Down()
        {//下载文件
            using MemoryStream ms = new MemoryStream();
            string content = "深圳欢迎您！";
            ms.Write(Encoding.UTF8.GetBytes(content));
            return File(ms.ToArray(), "application/octet-stream", "hello.txt");
        }
        public IActionResult Content()
        {//返回文本
            return Content("返回文本");
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
    public class Student
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }
}