Fileupload 檢查檔案類型 類別使用

 傳入m_file=Fileupload的ID

 private bool CheckFiles(string m_file)
    {
        bool m_return = true;

        FileUpload myFL = new FileUpload();

                   myFL = (FileUpload)this.roundpanel.FindControl(m_file);

roundpanel是放FileUpload的容器

roundpanel等於是FileUpload的上一層才能控制FileUpload
      
        String fileExtension = System.IO.Path.GetExtension(myFL.FileName).ToLower();  //取得上傳的檔案類型
       

       //檢查檔案大小

        if (myFL.PostedFile.ContentLength > 0)
        {
            String[] allowedExtensions = { ".gif", ".png", ".jpeg", ".jpg" };
            for (int i = 0; i < allowedExtensions.Length; i++)
            {
                if (fileExtension == allowedExtensions[i])
                {
                    return m_return;
                }
            }
        }
      
        return false;

    }