EF Core性能优化（一）

using System.Threading.Tasks;
using Core.Web.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace Core.Web.Controllers
{
    public class RegionController : Controller
    {
        private readonly DataContext _dataContext;
        public RegionController(DataContext dataContext)
        {
            _dataContext = dataContext;
        }
        //非跟踪查询
        public async Task<IActionResult> Index()
        {
            var regions = await _dataContext.Region.AsNoTracking().ToListAsync();
            return View(regions);
        }
        //非跟踪增加
        public async Task<bool> Add(Region region)
        {
            region.RegionID = 11;
            region.RegionDescription = "青岛";
            _dataContext.Entry(region).State = EntityState.Added;
            int res = await _dataContext.SaveChangesAsync();
            return res > 0;
        }
        //非跟踪修改
        public async Task<bool> Edit(Region region)
        {
            region.RegionID = 11;
            region.RegionDescription = "菏泽";
            _dataContext.Entry(region).State = EntityState.Modified;
            int res = await _dataContext.SaveChangesAsync();
            return res > 0;
        }
        //非跟踪删除
        public async Task<bool> Del(Region region)
        {
            region.RegionID = 11;
            _dataContext.Entry(region).State = EntityState.Deleted;
            int res = await _dataContext.SaveChangesAsync();
            return res > 0;
        }
    }
}