C#.Net 上傳圖片,限制圖片大小,檢查類型完整版

C#.Net 上傳圖片,限制圖片大小,檢查類型完整版

源代碼:

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處理圖片類，如檢查圖片大小,按寬度比例縮小圖片 

public   class  CImageLibrary
{
    public   enum  ValidateImageResult { OK, InvalidFileSize, InvalidImageSize }
   
    //檢查圖片大小  
    public   static  ValidateImageResult ValidateImage( string  file,   int  MAX_FILE_SIZE,   int  MAX_WIDTH,   intMAX_HEIGHT)
   {
       byte[] bs = File.ReadAllBytes(file);
      
       double  size = (bs.Length / 1024);
       //大於50KB  
       if  (size > MAX_FILE_SIZE)   return  ValidateImageResult.InvalidFileSize;
      Image img = Image.FromFile(file);
       if  (img.Width > MAX_WIDTH || img.Height > MAX_HEIGHT)   returnValidateImageResult.InvalidImageSize;
       return  ValidateImageResult.OK;
   }
   
    //按寬度比例縮小圖片  
    public   static  Image GetOutputSizeImage(Image imgSource,   int  MAX_WIDTH)
   {
      Image imgOutput = imgSource;
      
      Size size =   new  Size(imgSource.Width, imgSource.Height);
       if  (imgSource.Width <= 3 || imgSource.Height <= 3)   return  imgSource;   //3X3大小的圖片不轉換  
      
       if  (imgSource.Width > MAX_WIDTH || imgSource.Height > MAX_WIDTH)
      {
          double  rate = MAX_WIDTH / ( double)imgSource.Width;
         
          if  (imgSource.Height * rate > MAX_WIDTH)
         rate = MAX_WIDTH / ( double)imgSource.Height;
         
         size.Width = Convert.ToInt32(imgSource.Width * rate);
         size.Height = Convert.ToInt32(imgSource.Height * rate);
         
         imgOutput = imgSource.GetThumbnailImage(size.Width, size.Height,   null, IntPtr.Zero);
      }
      
       return  imgOutput;
   }
   
    //按比例縮小圖片  
    public   static  Image GetOutputSizeImage(Image imgSource, Size outSize)
   {
      Image imgOutput = imgSource.GetThumbnailImage(outSize.Width, outSize.Height,   null, IntPtr.Zero);
       return  imgOutput;
   }
   
    public   static   byte[] GetImageBytes( string  imageFileName)
   {
      Image img = Image.FromFile(imageFileName);
       return  GetImageBytes(img);
   }
   
    public   static   byte[] GetImageBytes(Image img)
   {
       if  (img ==   null)   return   null;
       try
      {
         System.IO.MemoryStream ms =   new  MemoryStream();
         img.Save(ms, ImageFormat.Jpeg);
          byte[] bs = ms.ToArray();
         ms.Close();
          return  bs;
      }
       catch  {   return   null; }
   }
   
    public   static  Image FromBytes( byte[] bs)
   {
       if  (bs ==   null)   return   null;
       try
      {
         MemoryStream ms =   new  MemoryStream(bs);
         Image returnImage = Image.FromStream(ms);
         ms.Close();
          return  returnImage;
         
      }
       catch  {   return   null; }
   }
}

上傳文件自定義類. 業務邏輯全部在CFileUpload類!

public   class  CFileUpload
{
    private  FileUpload _fileUpload;
    private   string  _savePath;
    private   string  _LastUploadedFile =   string.Empty;
    private   bool  _AutoGenFileName =   false;
    public   string  LastUploadedFile {   get  {   return  _LastUploadedFile; } }
   
    private   string  PICTURE_FILE = "[.gif.png.jpeg.jpg.bmp]";
    private   string  ZIP_FILE = "[.zip.rar]";
    private   string  MUILT_MEDIA_FILE = "[.mpeg.mpg.fla.exe.wma]";
   
    private   int  IMG_MAX_WIDTH = 0; //未指定寬度  
    private   int  IMG_MAX_HEIGHT = 0; //未指定高度  
   
    /// <summary>  
    /// 構造器  
    /// </summary>  
    /// <param name="fileUpload">Asp.net FileUpload對象</param>  
    /// <param name="savePath">保存目錄，不包含文件名</param>  
    /// <param name="autoGenFileName">自動生成文件名</param>  
    public  CFileUpload(FileUpload fileUpload,   string  savePath,   bool  autoGenFileName)
   {
      _savePath = savePath;
      _fileUpload = fileUpload;
      _AutoGenFileName = autoGenFileName;
   }
   
    /// <summary>  
    /// 構造器  
    /// </summary>  
    /// <param name="fileUpload">Asp.net FileUpload對象</param>  
    /// <param name="savePath">保存目錄，不包含文件名</param> 
    public  CFileUpload(FileUpload fileUpload,   string  savePath)
   {
      _savePath = savePath;
      _fileUpload = fileUpload;
   }
   
    /// <summary>  
    /// 上傳RAR文件  
    /// </summary> 
    public   bool  UploadRARFile()
   {
       return  DoUpload(ZIP_FILE);
   }
   
    /// <summary>  
    /// 上傳視頻文件  
    /// </summary> 
    public   bool  UploadVideo()
   {
       return  DoUpload(MUILT_MEDIA_FILE);
   }
   
    /// <summary>  
    /// 上傳圖片文件  
    /// </summary> 
    public   bool  UploadImage()
   {
       return  DoUpload(PICTURE_FILE);
   }
   
    public   bool  UploadImage( int  maxWidth,   int  maxHeight)
   {
       this.IMG_MAX_WIDTH = maxWidth;
       this.IMG_MAX_HEIGHT = maxHeight;
       return  DoUpload(PICTURE_FILE);
   }
   
    /// <summary>  
    /// 上傳任何支持的文件  
    /// </summary> 
    public   bool  UploadAnySupported()
   {
       return  DoUpload(PICTURE_FILE + ZIP_FILE + MUILT_MEDIA_FILE);
   }
   
    /// <summary>  
    /// 生成新的文件名  
    /// </summary>  
    private   string  GetNewFileName( string  folder,   string  fileName)
   {
       //_AutoGenFileName==true 或者文件名長度>50,自動生成32位GUID文件名  
       if  (_AutoGenFileName || StrUtils.GetStringLength(fileName) >= 50)
      {
          string  ext = System.IO.Path.GetExtension(fileName);
          string  newfile = Guid.NewGuid().ToString().Replace("-", "") + ext;
          return  folder + newfile;
      }
       else
      {
          if  (System.IO.File.Exists(folder + fileName))
         {
             string  ext = System.IO.Path.GetExtension(fileName);
             string  filebody = fileName.Replace(ext, "");
            
             int  x = 1;
             while  ( true) //如果文件存在，生成尾部帶(x)的文件
            {
                string  newfile = folder + filebody + "(" + x.ToString() + ")" + ext;
                if  (!System.IO.File.Exists(newfile))
                return  folder + filebody + "(" + x.ToString() + ")" + ext;
                else
               x++;
            }
         }
          else
          return  folder + fileName;
      }
   }
   
    /// <summary>  
    /// 最大支持小於1MB的文件。 
    /// </summary> 
    private   bool  AllowMaxSize( int  fileLength)
   {
       int  MAX_SIZE_UPLOAD = 1024; //最大支持上傳小於1MB的文件。 
       double  kb = fileLength / 1024;
       return  ( int)kb < MAX_SIZE_UPLOAD;
   }
   
    private   bool  DoUpload( string  allowedExtensions)
   {
       bool  fileOK =   false;
      
       if  (!_fileUpload.HasFile)   return   false;   //上傳控件中如果不包含文件，退出  
      
       // 得到文件的后綴  
       string  fileExtension = System.IO.Path.GetExtension(_fileUpload.FileName).ToLower();
      
       // 看包含的文件是否是被允許的文件后綴  
      fileOK = allowedExtensions.IndexOf(fileExtension) > 0;
      
       //檢查上傳文件大小  
      fileOK = fileOK & AllowMaxSize(_fileUpload.FileBytes.Length);
      
       if  (!fileOK)   return   false;   //如檢查不通過，退出  
      
       try
      {
          // 文件另存在服務器指定目錄下  
          string  savefile = GetNewFileName(_savePath, _fileUpload.FileName);
         
          if  (IsUploadImage(fileExtension))//保存圖片
         {
            System.Drawing.Image output = CImageLibrary.FromBytes(_fileUpload.FileBytes);
            
             // 檢查圖片寬度/高度/大小 
             if  ( this.IMG_MAX_WIDTH != 0 && output.Width >   this.IMG_MAX_WIDTH)
            {
               output = CImageLibrary.GetOutputSizeImage(output,   this.IMG_MAX_WIDTH);
            }
            Bitmap bmp =   new  Bitmap(output);
            bmp.Save(savefile, output.RawFormat);
         }
         else//其它任何文件
         {
            _fileUpload.PostedFile.SaveAs(savefile);
         }
         
         _LastUploadedFile = savefile;
          return   true;
      }
       catch
      {
          return   false;
      }
   }
   
    private   bool  IsUploadImage( string  fileExtension)
   {
       bool  isImage = PICTURE_FILE.IndexOf(fileExtension) > 0;
       return  isImage;
   }
}

使用說明:

頁面的Button.Click事件

protected   void  btnUploadImg_Click( object  sender, EventArgs e)
{
    try
   {
       if  (!FileUploadImg.HasFile)   return;
      
       string  virtualFilePath = "~//" + CAppConfiguration.Current.BbsUploadFilePath;
       string  savePath =   this.Server.MapPath(virtualFilePath);   //保存文件物理路徑  
      
       //調用CFileUpload類  
      CFileUpload upload =   new  CFileUpload(FileUploadImg, savePath,   false);
      
       //上傳圖片文件  
       bool  ret = upload.UploadImage();
       if  (ret)
      {
          string  filename = System.IO.Path.GetFileName(upload.LastUploadedFile);
          string  imgHTML = "<img alt=''''貼圖圖片'''' src=''''{0}'''' />";
          this.hfLastUploadImage.Value = filename;
         
          string  root = CGlobals.GetHttpRoot( this);
         
         imgHTML =   string.Format(imgHTML, root + "/" + CAppConfiguration.Current.BbsUploadFilePath + filename);
         FreeTextBox1.Text = FreeTextBox1.Text + "<br/>" + imgHTML;
         
         lblUploadImg.ForeColor = Color.Green;
         lblUploadImg.Visible =   true;
         lblUploadImg.Text = "上傳文件成功!";
      }
       else
      {
         lblUploadImg.ForeColor = Color.Red;
         lblUploadImg.Visible =   true;
         lblUploadImg.Text = "不支持格式或上傳失敗!";
      }
   }
    catch  (Exception ex)
   {
      CMsg.ShowException( this, ex);
   }
}