遍歷目錄就能獲得某種格式檔案(或者全部檔案)個數

private void button1_Click(object sender, EventArgs e)
        {
            string dirPath = @"E:\Wanda_Wifi\wanda\DataFiles\Triffic_A\ProcessedFiles";
            System.IO.DirectoryInfo dirInfo = new System.IO.DirectoryInfo(dirPath);
            int result = GetFilesCount(dirInfo);
            MessageBox.Show("檔案個數為："+result+"個");
        }
        public static int GetFilesCount(DirectoryInfo dirInfo)
        {

            int totalFile = 0;
            //totalFile += dirInfo.GetFiles().Length;//獲取全部檔案
            totalFile += dirInfo.GetFiles("*.txt").Length;//獲取某種格式
            foreach (System.IO.DirectoryInfo subdir in dirInfo.GetDirectories())
            {
                totalFile += GetFilesCount(subdir);
            }
            return totalFile;
        }