.NET Core 上传图片到七牛云

当然需要注册好七牛云的账号，配置好七牛云。

安装Nuget  -    MQiniu.Core  

获取AccessKey，SecretKey。登录七牛管理后台->个人信息->秘钥管理

　　　　public static string Upload(IFormFile file, string fileName)
        {
            try
            {
                var mac = new Mac(AccessKey, SecretKey);
                var ex = Path.GetExtension(file.FileName); //后缀
                if (ex == null || !((IList)FileTypes.FileType).Contains(ex.ToLower())) return string.Empty;

                var key = $"{fileName.ToLower()}/{DateTime.Now.Year}/{DateTime.Now:yyyyMMddHHmmssfff}{ex}";
                var bucket = Bucket;


                PutExtra extra = new PutExtra();
                PutPolicy putPolicy = new PutPolicy { Scope = bucket };

                // 如果需要设置为"覆盖"上传(如果云端已有同名文件则覆盖)，请使用 SCOPE = "BUCKET:KEY"
                // putPolicy.Scope = bucket + ":" + saveKey;
                //putPolicy.Scope = Bucket;

                putPolicy.SetExpires(3600);

                // 上传到云端多少天后自动删除该文件，如果不设置（即保持默认）则不删除
                putPolicy.DeleteAfterDays = 1;
                var token = Qiniu.Util.Auth.CreateUploadToken(mac, putPolicy.ToJsonString());
                Config config = new Config
                {
                    Zone = Zone.ZONE_CN_East,
                    UseHttps = true,
                    UseCdnDomains = true,
                    ChunkSize = ChunkUnit.U512K
                };
                // 设置上传区域
                // 设置 http 或者 https 上传
                // 表单上传
                FormUploader target = new FormUploader(config);
                HttpResult result = target.UploadStream(file.OpenReadStream(), key, token, extra);
                if (result.Code == 200) return key;
            }
            catch (Exception ex)
            {
                LogHelper.Error($"qiniu:{ex.ToString()}");
                return string.Empty;
            }
            return string.Empty;
        }

        private static class FileTypes
        {
            public static readonly string[] FileType = { ".jpg", ".png", ".jpeg", ".gif", ".bmp" };
        }