图片上传根据stream生成image

对于图片上传代码的整合

因为需要判断上传的图片的宽高是否符合尺寸，所以在最初拿到inputstream的时候，就直接获取image格式的图片

本来是想在下面的checkFile中获取的，不过直接使用System.Drawing.Image.FromStream(request.PostedFile.InputStream);的时候报错了，错误意思是说参数为空，应该是由于上面获取byte[]file的时候，关闭了stream，导致request.PostFile.InputStream也没有了，所以直接在IO中读取数据流的时候获取image格式对象

aaarticlea/png;base64,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" alt="" />

突然想起来还有个 image和bitmap之间的转换：

因为png格式的保存用的是bitmap空白处才不会填充，所以会使用到这种转换

Image originalImage = Image.FromFile(originalImagePath);
Bitmap oriImg = new Bitmap(originalImage);

public class UploadService
{
    public bool SaveAs(UploadRequest request, out string filePath, out string errMessage)
        {
            filePath = string.Empty;

            //**************************************初始化byte长度.
            byte[] file = new Byte[request.PostedFile.ContentLength];
            //**************************************读取stream，并转换为byte类型以及获取image类型
            System.IO.Stream stream = request.PostedFile.InputStream;
            stream.Read(file, , request.PostedFile.ContentLength);
            Image image = System.Drawing.Image.FromStream(stream);
            stream.Close();
            //**************************************判断条件
            if(!CheckFile(request,image, file, out errMessage)){
                return false;
            }
            //**************************************设置路径
            SetFile(ref request);
            filePath = request.SavePath;
            //**************************************保存至文件路径
            var fs = new FileStream(filePath, FileMode.Create, FileAccess.Write);
            fs.Write(file, , file.Length);
            fs.Flush();
            fs.Close();

            //**************************************获取相对路径
            filePath = GetSimplePath(filePath);
            if (string.IsNullOrEmpty(errMessage))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// 判断文件的相关条件
        /// </summary>
        /// <param name="request"></param>
        /// <param name="file"></param>
        /// <param name="errMessage"></param>
        /// <returns></returns>
        private bool CheckFile(UploadRequest request,Image image, byte[] file, out string errMessage)
        {
            errMessage = string.Empty;
            // 读取原始文件名
            string localFileName = Path.GetFileName(request.PostedFile.FileName);

            //得到扩展名
            var ext = localFileName.Substring(localFileName.LastIndexOf('.') + ).ToLower();
            //如果没有设定扩展名，则使用本身的扩展名存储
            if (string.IsNullOrEmpty(request.Ext))
            {
                request.Ext = ext;
            }
            //判断传入的数据
            if (file.Length == )
            {
                errMessage = "无数据提交";
                return false;
            }
            //判断文件是否超过限定大小
            if (file.Length > this.MaxFilesize)
            {
                errMessage = "文件大小超过" + this.MaxFilesize + "字节";
                return false;
            }
            //判断扩展名是否属于给定的
            if (request.Format!=null&& request.Format.Length >  && !request.Format.Contains(ext))
            {
                errMessage = "上传文件扩展名必需为：" + string.Join(",", request.Format);
                return false;
            }
            //判断宽高是否符合要求
            if (request.Width > ||request.Height>)
            {
                if (request.Width>&&Math.Abs( image.Width-request.Width)>)
                {
                    errMessage="宽不符合";
                    image.Dispose();
                    return false;
                }
                else if(request.Height>&&Math.Abs(image.Height-request.Height)>){
                    errMessage="高不符合";
                    image.Dispose();
                    return false;
                }
            }
            return true;
        }

        /// <summary>
        /// 设置保存路径以及创建文件夹
        /// </summary>
        /// <param name="request"></param>
        private void SetFile(ref UploadRequest request)
        {
            //如果路径没有设定，则按照给定的路径设置，不过给定路径的话，一定得先确保这个路径是正确的，且存在的
            if (string.IsNullOrEmpty(request.SavePath))
            {
                string subfolder = "day_" + DateTime.Now.ToString("yyMMdd");
                string fileFolder = Path.Combine(UploadConfigContext.UploadPath, request.Folder, subfolder);
                //文件全路径
                request.SavePath = Path.Combine(fileFolder,
                    string.Format("{0}{1}.{2}", DateTime.Now.ToString("yyyyMMddhhmmss"),
                    new Random(DateTime.Now.Millisecond).Next(), request.Ext)
                );
                if (!Directory.Exists(fileFolder))
                {
                    Directory.CreateDirectory(fileFolder);
                }
            }
        }
    }

    /// <summary>
    /// 上传使用的参数
    /// </summary>
    public class UploadRequest
    {
        /// <summary>
        /// 自行设置时，保存的子文件夹
        /// </summary>
        public string Folder { get; set; }
        /// <summary>
        /// 设置路径的，如果没设置，则代码自行设置
        /// </summary>
        public string SavePath { get; set; }
        /// <summary>
        /// 上传的数据
        /// </summary>
        public HttpPostedFileBase PostedFile { get; set; }
        /// <summary>
        /// 用来自定义控制扩展名的
        /// </summary>
        public string[] Format { get; set; }

        /// <summary>
        /// 控制宽，<=0则表示不管
        /// </summary>
        public int Width { get; set; }
        /// <summary>
        /// 控制高，<=0则表示不管
        /// </summary>
        public int Height { get; set; }

        /// <summary>
        /// 扩展名
        /// </summary>
        public string Ext { get; set; }
    }

图片上传代码