public IActionResult Get(string id) { if (!string.IsNullOrEmpty(id)) { _cacheService.Remove(id); } string code = CaptchaHelper.GetSingleObj().CreateCode(); string captoken = "V_" + Guid.NewGuid().ToString(); TimeSpan timeSpan = new TimeSpan(0, 0, 30); _cacheService.Add(captoken, code, timeSpan); var bitmap = CaptchaHelper.GetSingleObj().CreateBitmapByImgVerifyCode(code, 100, 40); MemoryStream ms = new MemoryStream(); bitmap.Save(ms, ImageFormat.Gif); byte[] arr = new byte[ms.Length]; ms.Position = 0; ms.Read(arr, 0, (int)ms.Length); ms.Close(); String strbaser64 = Convert.ToBase64String(arr); var send = new CacheM { Token = captoken, Img = strbaser64 }; return(Json(send)); }