本文例項環境及版本 .NetCore3.1

1、返回圖片檔案流

        /// <summary>
        /// 返回圖片檔案流
        /// </summary>
        /// <returns></returns>
        [HttpGet("GetFileInfo2")]
        public FileContentResult GetFileInfo2()
        {
            using (var sw = new FileStream("C:/YundiApp/FileData/images/20220617/2022061710060716957376.jpg
 
", FileMode.Open))
            {
                var contenttype =GetContentTypeForFileName("C:/YundiApp/FileData/images/20220617/2022061710060716957376.jpg");
                var bytes = new byte[sw.Length];
                sw.Read(bytes, 0, bytes.Length);
                sw.Close();
                return new FileContentResult(bytes, contenttype);
            }
        }

        
 
public static string GetContentTypeForFileName(string fileName)
        {
            //獲取檔案字尾
            string ext = Path.GetExtension(fileName);
            using (Microsoft.Win32.RegistryKey registryKey = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(ext))
            {
                if (registryKey == null
 
)
                    return null;
                var value = registryKey.GetValue("Content Type");
                return value?.ToString();
            }
        }

2、直接返回圖片檔案

        /// <summary>
        /// 返回圖片 直接返回圖片檔案
        /// </summary>
        /// <returns></returns>
        [HttpGet("GetFile")]
        public IActionResult GetFile()
        {return PhysicalFile(@"C:/YundiApp/FileData/images/20221017/202210171716154635.jpeg", "image/jpeg");
        }

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