public DataLoadForm(Form1 frm) { InitializeComponent(); this.frm = frm; MangeFile mangefile1 = new MangeFile(); int indexNum = mangefile1.NumberOfFile(Property.DatFileFolderPath); string[] DatFileNmae = new string[indexNum]; Property.DatFileNmae = new string[indexNum]; System.IO.DirectoryInfo di = new System.IO.DirectoryInfo(Property.DatFileFolderPath); int i = 0; foreach (System.IO.FileInfo File in di.GetFiles()) { if (File.Extension.ToLower().CompareTo(".dat") == 0) { string FileNameOnly = File.Name.Substring(0, File.Name.Length - 4); DatFileNmae[i] = FileNameOnly; } listBox1.Items.Add(DatFileNmae[i]); i++; } Property.DatFileNmae = DatFileNmae; }