在ASP.NET中为FCKEditor添加生成缩略图功能

FCKEditor应该是目前用得比较多的免费的在线编辑器，它的功能完善，并支持多种编程语言

在图片管理中，它只有简单的图象文件上传功能，在实际的操作中，可能不得不为一张比较大的图片制作一张小图，重新上传

为了简化这一操作，考虑在FCKEditor中添加图象文件上传后自动等比生成对应的缩略图。

先找到FCKEditor FOR .net的类库文档。因为该版本比较早期，可能需要转换。

首先在FileWorkerBase.cs中添加

        private const string DEFAULT_THUMBNAIL_IMAGE_TYPE = ".gif.bmp.png.jpg.";//可供创建缩略图的文件类型
         private const Int32 DEFAULT_THUMBNAIL_IMAGE_WIDTH = 240;//px 缩略图生成的宽度
         private const Int32 DEFAULT_THUMBNAIL_IMAGE_HEIGHT = 180;//px 缩略图生成的高度


         private Int32 sThumbnailImageWidth;
        private Int32 sThumbnailImageHeight;


        /// <summary>
        /// 缩略图宽
         /// </summary>
        /// <value>The width of the thumbnail image.</value>
        public Int32 ThumbnailImageWidth
        {
            get
            {
                object s = Application["FCKeditor:ThumbnailImageWidth"];
                if (s == null)
                {
                    s = Session["FCKeditor:ThumbnailImageWidth"];
                    if (s == null)
                    {
                        s = System.Configuration.ConfigurationSettings.AppSettings["FCKeditor:ThumbnailImageWidth"];
                    }
                }
                if (!Int32.TryParse(Convert.ToString(s), out sThumbnailImageWidth))
                {
                    sThumbnailImageWidth = DEFAULT_THUMBNAIL_IMAGE_WIDTH;
                }
                if (sThumbnailImageWidth < 1)
                {
                    sThumbnailImageWidth = DEFAULT_THUMBNAIL_IMAGE_WIDTH;
                }

                return sThumbnailImageWidth;
            }
        }
        /// <summary>
        /// 缩略图高
        /// </summary>
        /// <value>The Height of the thumbnail image.</value>
        protected Int32 ThumbnailImageHeight
        {
            get
            {

                object s = Application["FCKeditor:ThumbnailImageHeight"];
                if (s == null)
                {
                    s = Session["FCKeditor:ThumbnailImageHeight"];
                    if (s == null)
                    {
                        s = System.Configuration.ConfigurationSettings.AppSettings["FCKeditor:ThumbnailImageHeight"];
                    }
                }
                if (!Int32.TryParse(Convert.ToString(s), out sThumbnailImageHeight))
                {
                    sThumbnailImageHeight = DEFAULT_THUMBNAIL_IMAGE_HEIGHT;
                }
                if (sThumbnailImageHeight < 1)
                {
                    sThumbnailImageHeight = DEFAULT_THUMBNAIL_IMAGE_HEIGHT;
                }

                return sThumbnailImageHeight;

            }
        }
        /// <summary>
        /// 可创建缩略图的文件类型
        /// </summary>
        /// <value>The type of the thumbnail image.</value>
        protected string ThumbnailImageType
        {
            get
            {
                return DEFAULT_USER_FILES_TYPE;
            }
        }
        /// <summary>
        /// 创建缩略图，宽度指定，高度自适应
        /// </summary>
        /// <param name="filePath">文件路径</param>
        public void CreateThumbnailImage(string filePath)
        {
            if (filePath == null || filePath.Trim().Length == 0)
            {
                return;//如果文件路径为空
            }
            string sFilePath = filePath.Replace("/", "\\");
            string sFileFolder = sFilePath.Substring(0, sFilePath.LastIndexOf("\\") + 1);
            string sFileName = sFilePath.Substring(0, sFilePath.LastIndexOf(".")).Substring(sFilePath.LastIndexOf("\\") + 1);
            string sExt = System.IO.Path.GetExtension(sFilePath);
            if (!this.ThumbnailImageType.ToLower().Contains(sExt.ToLower() + "."))//包含有效的可用于创建缩略图的文件类型
            {
                return;//如果文件不是图片文件
            }
            if (!System.IO.File.Exists(sFilePath))
            {
                return;//如果文件不存在
            }

            System.Drawing.Image img = null;
           
            try
            {
                img = Bitmap.FromFile(sFilePath);
                //if (img.Width <= this.ThumbnailImageWidth && img.Height <= this.ThumbnailImageHeight)
                if (img.Width <= this.ThumbnailImageWidth)
                {//如果文件宽小于缩略图尺寸
                    img.Dispose();
                    return;
                }
                double percent = (double)img.Width / (double)img.Height;
              
                System.Drawing.Image.GetThumbnailImageAbort callback = new Image.GetThumbnailImageAbort(this.GetThumbnailImageAbort);
                Image smallImg = img.GetThumbnailImage(this.ThumbnailImageWidth, Convert.ToInt32(this.ThumbnailImageWidth / percent), callback, IntPtr.Zero);
                smallImg.Save(string.Format(@"{0}{1}_s.jpg", sFileFolder, sFileName), System.Drawing.Imaging.ImageFormat.Jpeg);
                smallImg.Dispose();
            }
            catch (Exception ex)
            {
                //TODO ANYTHING
                //throw ex;
            }
            finally
            {
                if (img != null)
                {
                    img.Dispose();
                }
            }
        }

        protected bool GetThumbnailImageAbort()
        {
            return false;
        }

在FileBrowserConnector.css中修改FileUpload方法（在文件上传成功后的处理代码后面添加）

//对图片文件生成缩略图
this.CreateThumbnailImage(sFilePath);

在Uploader.cs中修改OnLoad方法，同样在文件上传成功后的处理代码后面添加上面的代码

完成后，FCKEditor自动在上传图象文件后生成缩略图，缩略图自动在原来的文件名后添加_s，并以jpg格式保存

当然它只对指定格式的图象文件，并且大小超过设置的宽度时才会生成缩略图。

希望此文件对大家有所帮助