Question

我在常量中遇到问题换行符：

    protected void UploadButton_Click(object sender, EventArgs e)
    {
        string theUserId = Session["UserID"].ToString();
        if (FileUploadControl.HasFile)
        {
            try
            {
                string filename = Path.GetFileName(FileUploadControl.FileName);
                FileUploadControl.SaveAs(Server.MapPath("~/userdata/"+theUserId+"/uploadedimage/) + filename);
//here
                StatusLabel.Text = "Upload status: File uploaded!";
            }
            catch (Exception ex)
            {
                StatusLabel.Text = "Upload status: The file could not be uploaded. The following error occured: " + ex.Message;
            }
        }
    }

}

我也想知道有没有办法在上传时调整图片大小，如果是这样，怎么样？

因为这是一个保存，因为我的fileupload控件会覆盖任何已经存在用户ID的文件夹吗？（我想要什么，需要什么）

Answer 1

好吧，我已经可以在你的错误上面的行中看到你在/ uploadedimage /之后缺少一个引用，并且最后一个paren应该在文件名之后没有/ uploadedimage /

Answer 2

常量中的换行符

FileUploadControl.SaveAs(Server.MapPath("~/userdata/"+theUserId+"/uploadedimage/) + filename); //here

应该是：

FileUploadControl.SaveAs(Server.MapPath("~/userdata/"+theUserId+"/uploadedimage/") + filename); //here

图片调整大小/缩略图

如果是您正在播放的缩略图，则可以使用Image.GetThumbnailImage。基本实现是这样的：

using (System.Drawing.Image fullsizeImage =
         System.Drawing.Image.FromFile(originalFilePath))
{
       // these calls to RotateFlip aren't essential, but they prevent the image 
       // from using its built-in thumbnail, which is invariably poor quality.
       // I like to think of it as shaking the thumbnail out ;)
       fullsizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);
       fullsizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);

       using (System.Drawing.Image thumbnailImage = 
         fullsizeImage.GetThumbnailImage(newWidth, newHeight, null, IntPtr.Zero))
       {
            thumbnailImage.Save(newFilePath);
       }
}

<强>改写

覆盖是默认行为，因此将同一文件上传到同一个UserID将替换它。

Answer 3

您是否错过了引用或是错字：

Server.MapPath("~/userdata/"+theUserId+"/uploadedimage/")

我还建议在使用大量字符串连接时使用string.Format（通常在必须多次使用+时执行此操作）：

Server.MapPath(string.Format("~/userdata/{0}/uploadedimage/", theUserId))

编辑以回复调整评论：

以下是类似SO问题的链接：

how to resize an image whileing saving in an folder

Answer 4

newline变量有哪个值？

下面为收集的值添加了一个Trim（），并提供了一种查看之后收集的每个字符串值的方法。

protected void UploadButton_Click(object sender, EventArgs e)
{
  string theUserId = Session["UserID"].ToString().Trim(); // add Trim()
  if (FileUploadControl.HasFile && !String.IsNullOrEmpty(theUserId)) // add test
  {
    try
    {
      string filename = Path.GetFileName(FileUploadControl.FileName);
      Console.WriteLine(filename);
      string filepath = string.Format("~/userdata/{0}/uploadedimage/", theUserId);
      Console.WriteLine(filepath );
      string mapPath = Server.MapPath(filepath);
      Console.WriteLine(mapPath );
      FileUploadControl.SaveAs(mapPath + filename);
      StatusLabel.Text = "Upload status: File uploaded!";
    }
    catch (Exception ex)
    {
      StatusLabel.Text = "Upload status: The file could not be uploaded. The following error occured: " + ex.Message;
    }
  }
}

Just Trim（）字符串值中包含换行符。

fileupload newline in constant

4 个答案: