API删除文件

using System;
using System.Runtime.InteropServices;
namespace ConsoleApplication1
{
    class Program
    {
        [DllImport("kernel32.dll")]
        public static extern uint DeleteFile(string fileName);
        [DllImport("kernel32.dll")]
        public static extern uint GetLastError();
        [DllImport("kernel32.dll")]
        public static extern uint FormatMessage(uint dwFlag, ref IntPtr source, uint messageId, uint languageId, ref string lpBuffer, uint size, ref IntPtr va_list);
        static void Main(string[] args)
        {
            string str = null;
            IntPtr tempptr = IntPtr.Zero;
            if (DeleteFile("C:	est.txt") != 0)
                Console.Write("删除成功！");
            else{
                FormatMessage(0x1300, ref tempptr, GetLastError(), 0, ref str, 0, ref tempptr);
                Console.Write("删除失败！
失败原因：" + str);
            }
        }
    }
}