.net core使用ViewComponent将页面图片转码成base64

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Caching.Memory;

namespace MyPorject.MVC.ViewComponents
{
    public class ImgToBase64ViewComponent : ViewComponent
    {
        private readonly IHostingEnvironment _hostingEnvironment;
        private readonly IMemoryCache _memoryCache;
        public ImgToBase64ViewComponent(IHostingEnvironment hostingEnvironment, IMemoryCache memoryCache)
        {
            _hostingEnvironment = hostingEnvironment;
            _memoryCache = memoryCache;
        }

        public async Task InvokeAsync(string src)
        {
            string cacheKey = src;
            string result = await _memoryCache.GetOrCreateAsync(cacheKey, async entry =>
              {
                  string webRootPath = _hostingEnvironment.WebRootPath;
                  string path = webRootPath + @"\" + src.TrimStart('~').TrimStart('/').Replace(@"/", @"\").ToString();

                  try
                  {
                      using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read))
                      {
                          var byteArray = new byte[fs.Length];
                          await fs.ReadAsync(byteArray, 0, byteArray.Length);
                          result = "data:image/jpeg;base64," + Convert.ToBase64String(byteArray);
                      }
                  }
                  catch (Exception ex)
                  {
                      result = ex.Message;
                  }
                  return await Task.FromResult(result);
              });
            return View("", result);
        }
    }
}

添加default.cshtml

使用方法：

将原来src中改成Component.InvokeAsync 就可以使用了

效果如图：