سلام
تابع زیر عمل کپی رو به همراه نمایش Progress bar استفاده میکنم
ولی هنگامی که پوشه رو کپی میکنم یا تعداد زیادی فایل؛ این ارور رو میده:
"Value of '2' is not valid for 'Value'. 'Value' should be between 'minimum' and 'maximum'.\r\nParameter name: Value"

اصل تابع:

public static void CopyFile(string FileSource, string FileDestination, ProgressBar progressBar1)
{
   int NumRead ;
   long FileLength ;
   System.IO.FileStream From = new System.IO.FileStream(FileSource, System.IO.FileMode.Open) ;
   System.IO.FileStream To = new System.IO.FileStream(FileDestination, System.IO.FileMode.CreateNew) ;
   byte[] buffer = new byte[1024] ;
   FileLength = From.Length ;
   progressBar1.Minimum = 0 ;
   progressBar1.Maximum = (int)FileLength ;
   while (FileLength > 0)
   {
      System.IO.BinaryReader Reader = new System.IO.BinaryReader(From) ;
      NumRead = Reader.Read(buffer, 0, 1024) ;
      FileLength = FileLength - NumRead ;
      System.IO.BinaryWriter Writer = new System.IO.BinaryWriter(To) ;
      Writer.Write(buffer, 0, NumRead) ;
      FileInfo aaaa = new FileInfo(FileSource) ;
      Int64 a = aaaa.Length ;
      Int64 a1 = a /= 1000 ;
      //MessageBox.Show(a1.ToString()) ;

      progressBar1.Maximum = int.Parse(a1.ToString()) ;
      progressBar1.Value = progressBar1.Value + (NumRead /= 1000) ;

      Writer.Flush() ;
   }

   From.Close() ;
   To.Close() ;
   if (progressBar1.Value > 99)
   {
       progressBar1.Value = 0 ;
       //MessageBox.Show( "Copy Finished successfuly" ) ;
   }
}

مشکل از کجاست؟
ممنون میشم راهنمایی بفرمائین.

سلام
این کد را امتحان کنید:

public static void  CopyFile(string  FileSource, string  FileDestination, ProgressBar progressBar1)
{
    const int  BUFFER_SIZE = 64 * 1024 ;

    progressBar1.Minimum = 0 ;
    progressBar1.Maximum = 100 ;
    progressBar1.Value = 0 ;

    using  (var  From = new  System.IO.FileStream(FileSource, System.IO.FileMode.Open, System.IO.FileAccess.Read))
    using  (var  To = new  System.IO.FileStream(FileDestination, System.IO.FileMode.Create, System.IO.FileAccess.Write))
    {
        long  SumCopy = 0 ;
        long  FileLength = From.Length ;
        if  (FileLength <= 0) return  ;

        byte [] buffer = new byte [BUFFER_SIZE] ;
        while  (true )
        {
            int  NumRead = From.Read(buffer, 0, BUFFER_SIZE) ;
            if  (NumRead <= 0) break  ; //END 

            To.Write(buffer, 0, NumRead) ;
            SumCopy += NumRead ;

            progressBar1.Value = (int )(100 * SumCopy / FileLength) ;
        }
    }

    //MessageBox.Show( "Copy Finished successfuly" ) ; 
}