FileUpLoad控件-优快云博客

本文介绍了一个ASP.NET中的文件上传示例，演示如何验证上传文件的类型并确保只接受特定格式（如.gif、.png、.jpeg、.jpg）。通过检查文件扩展名并与允许的扩展名列表进行比较来实现文件类型的验证。

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protected void Page_Load(object sender, EventArgs e)
{
    if(IsPostBack)
    {
        Boolean fileOK = false;
        String path = Server.MapPath("~/UploadedImages/");
        if (FileUpload1.HasFile)
        {
            String fileExtension =
                System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
            String[] allowedExtensions =
                {".gif", ".png", ".jpeg", ".jpg"};
          for ( int i = 0; i < allowedExtensions.Length; i++)
          {
               if (fileExtension == allowedExtensions[i])
               {
                    fileOK = true;
               }
          }
        }

        if (fileOK)
        {
            try
            {
                FileUpload1.PostedFile.SaveAs(path
                    + FileUpload1.FileName);
                Label1.Text = "File uploaded!";
            }
            catch (Exception ex)
            {
                Label1.Text = "File could not be uploaded.";
            }
        }
        else
        {
            Label1.Text = "Cannot accept files of this type.";
        }
    }
}