C# 判断文件有没占用

using System;

using System.Collections.Generic;

using System.Text;

using System.Runtime.InteropServices;

namespace AdminTools

{

    public static class FileTools

    {

        [DllImport("kernel32.dll")]

        private static extern IntPtr _lopen(string lpPathName, int iReadWrite);

        [DllImport("kernel32.dll")]

        private static extern bool CloseHandle(IntPtr hObject);

        private const int OF_READWRITE = 2;

        private const int OF_SHARE_DENY_NONE = 0x40;

        private static readonly IntPtr HFILE_ERROR = new IntPtr(-1);

        /// <summary>   

        /// 检查文件是否已经打开   

        /// </summary>   

        /// <param name="strfilepath">要检查的文件路径</param>          

        /// <returns>true文件已经打开,false文件可用未打开</returns>   

        public static bool FileUsing(string strfilepath)

        {

            string vFileName = strfilepath;

            // 先检查文件是否存在,如果不存在那就不检查了   

            if (!System.IO.File.Exists(vFileName))

            {

                return true;

            }

            // 打开指定文件看看情况   

            IntPtr vHandle = _lopen(vFileName, OF_READWRITE | OF_SHARE_DENY_NONE);

            if (vHandle == HFILE_ERROR)

            { // 文件已经被打开                   

                return true;

            }

            CloseHandle(vHandle);

            // 说明文件没被打开，并且可用  

            return false;

        }

    }

}