c# 对文件的操作

 private void button1_Click(object sender, EventArgs e)
        {
            string filePath = textBox1.Text.Trim();
            string directoryName = filePath.Substring(0, filePath.LastIndexOf("\"));//根据文件路径获取到该文件夹
            string dir = Path.GetDirectoryName(filePath);   //获取文件所在的目录
            string fileName = Path.GetFileName(filePath);   //获取文件名，带后缀
            string fileNameNoExt = Path.GetFileNameWithoutExtension(filePath); //获取文件名，不带后缀
            string ExtName = Path.GetExtension(filePath);   //获取文件的后缀名
            string[] Files = Directory.GetFiles(dir, "*.Png");  //获取该目录下所有以后缀名为Png结尾的文件
            List<string> files = new List<string>();
            foreach (var f in Files)
            {
                string nameFull = Path.GetFileNameWithoutExtension(f);
                string name = nameFull.Substring(0, nameFull.LastIndexOf("_"));
                if (fileNameNoExt == name)
                    files.Add(f);
            }
            string str = string.Join(",", files.ToArray());//以"，"存在于str中
        }