上传图片控件

Question

先做缩略图处理,然后将缩略图以Base64字符的形式保存到数据库表中比较先做缩略图处理,然后Select 1 From imglist Where str_img like @str_img         /// <summary>
        /// 回调
        /// </summary>
        /// <returns></returns>
        public bool ThumbnailCallback()
        {
            return false;
        }        /// <summary>
        /// 生成缩略图,返回缩略图的Image对象
        /// </summary>
        /// <param name="Width">缩略图宽度</param>
        /// <param name="Height">缩略图高度</param>
        /// <returns>缩略图的Image对象</returns>
        public Image GetImage(int Width, int Height)
        {
            Image img;
            Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
            img = srcImage.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);
            return img;
        }
        // 把图片转 Base64 编码
        public static string ImageToBase64(System.Drawing.Image image, System.Drawing.Imaging.ImageFormat format)
        {
            using (MemoryStream ms = new MemoryStream())
            {
                // Convert Image to byte[] 
                image.Save(ms, format);
                byte[] imageBytes = ms.ToArray();                // Convert byte[] to Base64 String 
                string base64String = Convert.ToBase64String(imageBytes);
                return base64String;
            }
        }

Answer 1

        /// <summary>
        /// 计算文件的MD5校验
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public static string GetMD5HashFromFile(string fileName)
        {
            try
            {
                FileStream file = new FileStream(fileName, FileMode.Open);
                System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
                byte[] retVal = md5.ComputeHash(file);
                file.Close();                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < retVal.Length; i++)
                {
                    sb.Append(retVal[i].ToString("x2"));
                }
                return sb.ToString();
            }
            catch (Exception ex)
            {
                throw new Exception("GetMD5HashFromFile() fail,error:" + ex.Message);
            }
        }

Answer 2

上边已经给了你获取文件md5的方法了呀md5原本就是为了校验传输而生的