读者朋友：
    您好，使用下面的代码（我们测试好使的）试一下：
protected void UploadImage_OnClick(object sender, EventArgs e)
    {    
        try
        {
            this.labIamge.Visible = true;
            labIamge.Text = "";
            if (imageUpload.PostedFile.FileName == "")
            {
                Response.Write(ccObj.MessageBox( "要上传的文件不允许为空！"));
                return;
            }
            else
            {
                string filePath = imageUpload.PostedFile.FileName;
                string filename = filePath.Substring(filePath.LastIndexOf("\\") + 1);
                string fileEx = filePath.Substring(filePath.LastIndexOf(".") + 1);
                string serverpath = Server.MapPath(@"~\Images\ftp\") + filename;
                string relativepath = @"~\images\ftp\" + filename;
                string strSql = "select * from tb_Image where ImageName='"+filename+"'";
                DataTable dsTable = dbObj.GetDataSetStr(strSql, "tbImage");
                if (dsTable.Rows.Count > 0)
                {
                    Response.Write(ccObj.MessageBox("该图片已存在！"));
                }
                else
                {
                    //判断图片格式
                    if (fileEx == "jpg" || fileEx == "bmp" || fileEx == "gif")
                    {
                        //生成缩略图
                        System.Drawing.Image image, newimage;
                        image = System.Drawing.Image.FromFile(filePath);
                        System.Drawing.Image.GetThumbnailImageAbort callb=null;
                        newimage = image.GetThumbnailImage(67, 90, callb, new System.IntPtr());
                        //把缩略图保存到指定的虚拟路径
                        newimage.Save(serverpath);
                        //释放image对象占用的资源
                        newimage.Dispose();
                        image.Dispose();
                        //imageUpload.PostedFile.SaveAs(serverpath);
                        //将图片的信息保存在数据库中
                        string strAddSql = "insert into tb_Image(ImageName,ImageUrl)";
                        strAddSql += "Values('" + filename + "','" + relativepath + "')";
                        SqlCommand myCmd = dbObj.GetCommandStr(strAddSql);
                        dbObj.ExecNonQuery(myCmd);
                        dlImageBind();
                        Response.Write(ccObj.MessageBox("上传成功！"));
                    }
                    else
                    {
                        Response.Write(ccObj.MessageBox("上传的图片扩展名错误！"));

                    }
                   
                }
               
            }
        
        }
        catch (Exception error)
        {
            labIamge.Text = "处理发生错误！原因：" + error.ToString();
        }

    }