删除指定目录下的所有文件与更改文件扩展名

 //删除指定目录下的所有文件
        private void button1_Click(object sender, EventArgs e)
        {
            DeleteFilesAndFolders(textBox1.Text);//路径
        }
        void DeleteFilesAndFolders(string path) {
            //DirectoryInfo dinfo = new DirectoryInfo(path);
            string[] files = Directory.GetFiles(path);
            foreach(var file in files){
                File.Delete(file);//文件删除
            }

            string[] dir = Directory.GetDirectories(path);
            foreach(var d in dir){
                DeleteFilesAndFolders(d);
                Directory.Delete(d);//文件夹删除
            }
          
        }

       //更改文件扩展名
        private void button1_Click(object sender, EventArgs e)
        {
            FileInfo finfo = new FileInfo(textBox1.Text);//textBox1.Text 文件路径
            string strPath = textBox1.Text.Substring(0,textBox1.Text.LastIndexOf("."));//去掉扩展名
            string newpath = strPath + textBox2.Text.Trim();//新的文件路径
            finfo.MoveTo(newpath);
        }