[C#.Net]判断文件是否被占用的两种方法

今天开发产线测试Tool时发现日志文件会几率性的被占用，上网浏览找到最简单的代码(API或者FileStream)，在这里抛砖引玉下。

第一种方法:API

 using System.IO;
 using System.Runtime.InteropServices;  

 [DllImport("kernel32.dll")]
 public static extern IntPtr _lopen(string lpPathName, int iReadWrite);  

 [DllImport("kernel32.dll")]
 public static extern bool CloseHandle(IntPtr hObject);  

 public const int OF_READWRITE = ;
 public const int OF_SHARE_DENY_NONE = 0x40;
 public readonly IntPtr HFILE_ERROR = new IntPtr(-);
 private void button1_Click(object sender, EventArgs e)
 {
     string vFileName = @"c:\temp\temp.bmp";
     if (!File.Exists(vFileName))
     {
         MessageBox.Show("文件都不存在!");
         return;
     }
     IntPtr vHandle = _lopen(vFileName, OF_READWRITE | OF_SHARE_DENY_NONE);
     if (vHandle == HFILE_ERROR)
     {
         MessageBox.Show("文件被占用！");
         return;
     }
     CloseHandle(vHandle);
     MessageBox.Show("没有被占用！");
 }  

第二种方法:FileStream

 public static bool IsFileInUse(string fileName)
  {
         bool inUse = true;  

         FileStream fs = null;
         try
         {  

             fs = new FileStream(fileName, FileMode.Open, FileAccess.Read,  

             FileShare.None);  

             inUse = false;
         }
         catch
         {
         }
         finally
         {
             if (fs != null)  

                 fs.Close();
         }
         return inUse;//true表示正在使用,false没有使用
 }  

项目代码的部分(VB.Net)

  Sub Prepare()
         If File.Exists(logRW) Then File.Delete(logRW)
         Dim bflag As Boolean = False
         Try
             Do
                 Shell("CMD.exe /C RW.exe /Command=LimitA.rw /LogFile=LimitA.log", AppWinStyle.Hide, True, )
                 Threading.Thread.Sleep()
                 While (IsFileInUse("LimitA.log"))
                     Threading.Thread.Sleep()
                 End While

                 If File.Exists(logRW) Then
                     Dim All As String = My.Computer.FileSystem.ReadAllText(logRW)
                     '检查LogRW的0x01的位置的值是否为0x08
                     If All.Contains("Read EC Byte 0x01 = 0x80") Then
                         bflag = True
                     End If
                 End If
             Loop Until bflag

             Using sr As New StreamReader(logRW)
                 Do Until sr.EndOfStream
                     Dim s As String = sr.ReadLine
                     If s.Contains("Set Environment RwLOCAL3") Then
                         'Set Environment RwLOCAL3 = 4608 (DEC)
                         LimitA = CDbl(s.Split(New String() {"=", "("}, StringSplitOptions.RemoveEmptyEntries)())
                         Console.WriteLine("Limit Current: " & LimitA)
                         LogStr = LogStr & vbCrLf & "Limit Current: " & LimitA
                         Exit Do
                     End If
                 Loop
             End Using

         Catch ex As Exception
             Console.WriteLine(ex.Message & Err.Description)
             Environment.Exit()
         End Try
     End Sub

     Function IsFileInUse(ByVal fileName As String)
         Dim inUse As Boolean = True
         Dim fs As FileStream = Nothing
         Try
             fs = New FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.None)
             inUse = False
         Catch ex As Exception

         Finally
             If (fs IsNot Nothing) Then
                 fs.Close()
             End If
         End Try
         Return inUse
     End Function