webconfig限制了大小，控件上传文件，不执行代码就直接报错！如何解决

Question

不要在config里设置，在程序里判断

Answer 1

上传图片文件限制大小示例
 // 上传图片
      protected void imgBtnLoad_Click(object sender, ImageClickEventArgs e)
    {
        if (!fulPhoto.HasFile)
        {
            lbMessage.Text = "请选择上传图片！";
            return;
        }
        else
        {
            try
            {
                //获取上传文件路径
                string filePath = fulPhoto.PostedFile.FileName;
                //获取上传文件后缀
                string fileExt = filePath.Substring(filePath.LastIndexOf(".") + 1);
                //限定上传格式
                if (fileExt.ToLower() == "gif" || fileExt.ToLower() == "jpg" || fileExt.ToLower() == "bmp" || fileExt.ToLower() == "png")
                {
                    if (fulPhoto.PostedFile.ContentLength > 5120000)
                    {
                        lbMessage.Text = "限定上传图片的大小不能超出5M！";
                        return;
                    }
                    else
                    {
                        //根据时间生成文件名
                        string nowTime = Album.CreateDateTimeString();
                        string fileName = nowTime + "." + fileExt;
                        //源文件保存路径
                        string savePath = Server.MapPath("UpFile/");
                        //缩略图保存路径
                        string imgPath = Server.MapPath("UpSmall/");
                        //上传图片
                        fulPhoto.PostedFile.SaveAs(savePath + fileName);
                        //创建自定义Album类对象实例
                        Album am = new Album();
                        //根据图片的s宽、高比例生成缩略图
                        System.Drawing.Image img = System.Drawing.Image.FromFile(savePath + fileName);
                        if (img.Width >= img.Height)
                        {
                            am.GetThumbnail(savePath + fileName, imgPath + fileName, 400, 300, "Cut");
                        }//CodeGo.net/
                        else
                        {
                            am.GetThumbnail(savePath + fileName, imgPath + fileName, 320, 350, "Cut");
                        }
                        //文件类型
                        string p_type = fulPhoto.PostedFile.ContentType;
                        //文件大小
                        int p_size = fulPhoto.PostedFile.ContentLength;
                        int categoryId = Convert.ToInt32(ddlCategory.SelectedValue);
                        //调用类方法将数据插入到数据库
                        int result = am.AddPhoto(tbName.Text.Trim(), tbDescript.Text.Trim(), fileName, p_type, p_size, categoryId);
                        ScriptManager.RegisterStartupScript(UpdatePanel1, typeof(UpdatePanel), "scriptname", "alert('图片上传成功！！');", true);
                    }
                }
                else
                {
                    lbMessage.Text = "只允许上传gif，jpg，bmp，png格式的图片文件!";
                    return;
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message, ex);
            }
        }
    }