现在,我知道的唯一方法就是打开文件并捕获任何
System.IO.IOException
。
当我面对类似问题时,我完成了以下代码:
public class FileManager
{
private string _fileName;
private int _numberOfTries;
private int _timeIntervalBetweenTries;
private FileStream GetStream(FileAccess fileAccess)
{
var tries = 0;
while (true)
{
try
{
return File.Open(_fileName, FileMode.Open, fileAccess, Fileshare.None);
}
catch (IOException e)
{
if (!IsFileLocked(e))
throw;
if (++tries > _numberOfTries)
throw new MyCustomException("The file is locked too long: " + e.Message, e);
Thread.Sleep(_timeIntervalBetweenTries);
}
}
}
private static bool IsFileLocked(IOException exception)
{
int errorCode = Marshal.GetHRForException(exception) & ((1 << 16) - 1);
return errorCode == 32 || errorCode == 33;
}
// other code
}
RestartManagerAPI,现在跟踪该信息。 重新启动管理器API可以从Windows Vista和Windows Server 2008开始(RestartManager:运行时要求
)。I组合了符合文件路径并返回所有正在锁定该文件的进程的代码。
List<Process>
update
thehere是另一个使用示例代码
如何使用RESTART MANAGAR API。不幸的是,如果您考虑一下,那么无论如何,该信息将是毫无价值的,因为该文件可能会锁定下一个第二秒(请读:短时间pan)。
为什么您需要知道该文件是否还是锁定的?知道这可能会给我们一些其他给您好的建议的方法。如果您的代码看起来像这样:
static public class FileUtil
{
[StructLayout(LayoutKind.Sequential)]
struct RM_UNIQUE_PROCESS
{
public int dwProcessId;
public System.Runtime.InteropServices.ComTypes.FILETIME ProcessStartTime;
}
const int RmRebootReasonNone = 0;
const int CCH_RM_MAX_APP_NAME = 255;
const int CCH_RM_MAX_SVC_NAME = 63;
enum RM_APP_TYPE
{
RmUnknownApp = 0,
RmMainWindow = 1,
RmOtherWindow = 2,
RmService = 3,
RmExplorer = 4,
RmConsole = 5,
RmCritical = 1000
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
struct RM_PROCESS_INFO
{
public RM_UNIQUE_PROCESS Process;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCH_RM_MAX_APP_NAME + 1)]
public string strAppName;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCH_RM_MAX_SVC_NAME + 1)]
public string strServiceShortName;
public RM_APP_TYPE ApplicationType;
public uint AppStatus;
public uint TSSessionId;
[MarshalAs(UnmanagedType.Bool)]
public bool bRestartable;
}
[DllImport("rstrtmgr.dll", CharSet = CharSet.Unicode)]
static extern int RmRegisterResources(uint pSessionHandle,
UInt32 nFiles,
string[] rgsFilenames,
UInt32 nApplications,
[In] RM_UNIQUE_PROCESS[] rgApplications,
UInt32 nServices,
string[] rgsServiceNames);
[DllImport("rstrtmgr.dll", CharSet = CharSet.Auto)]
static extern int RmStartSession(out uint pSessionHandle, int dwSessionFlags, string strSessionKey);
[DllImport("rstrtmgr.dll")]
static extern int RmEndSession(uint pSessionHandle);
[DllImport("rstrtmgr.dll")]
static extern int RmGetList(uint dwSessionHandle,
out uint pnProcInfoNeeded,
ref uint pnProcInfo,
[In, Out] RM_PROCESS_INFO[] rgAffectedApps,
ref uint lpdwRebootReasons);
/// <summary>
/// Find out what process(es) have a lock on the specified file.
/// </summary>
/// <param name="path">Path of the file.</param>
/// <returns>Processes locking the file</returns>
/// <remarks>See also:
/// http://msdn.microsoft.com/en-us/library/windows/desktop/aa373661(v=vs.85).aspx
/// http://wyupdate.googlecode.com/svn-history/r401/trunk/frmFilesInUse.cs (no copyright in code at time of viewing)
///
/// </remarks>
static public List<Process> WhoIsLocking(string path)
{
uint handle;
string key = Guid.NewGuid().ToString();
List<Process> processes = new List<Process>();
int res = RmStartSession(out handle, 0, key);
if (res != 0)
throw new Exception("Could not begin restart session. Unable to determine file locker.");
try
{
const int ERROR_MORE_DATA = 234;
uint pnProcInfoNeeded = 0,
pnProcInfo = 0,
lpdwRebootReasons = RmRebootReasonNone;
string[] resources = new string[] { path }; // Just checking on one resource.
res = RmRegisterResources(handle, (uint)resources.Length, resources, 0, null, 0, null);
if (res != 0)
throw new Exception("Could not register resource.");
//Note: there's a race condition here -- the first call to RmGetList() returns
// the total number of process. However, when we call RmGetList() again to get
// the actual processes this number may have increased.
res = RmGetList(handle, out pnProcInfoNeeded, ref pnProcInfo, null, ref lpdwRebootReasons);
if (res == ERROR_MORE_DATA)
{
// Create an array to store the process results
RM_PROCESS_INFO[] processInfo = new RM_PROCESS_INFO[pnProcInfoNeeded];
pnProcInfo = pnProcInfoNeeded;
// Get the list
res = RmGetList(handle, out pnProcInfoNeeded, ref pnProcInfo, processInfo, ref lpdwRebootReasons);
if (res == 0)
{
processes = new List<Process>((int)pnProcInfo);
// Enumerate all of the results and add them to the
// list to be returned
for (int i = 0; i < pnProcInfo; i++)
{
try
{
processes.Add(Process.GetProcessById(processInfo[i].Process.dwProcessId));
}
// catch the error -- in case the process is no longer running
catch (ArgumentException) { }
}
}
else
throw new Exception("Could not list processes locking resource.");
}
else if (res != 0)
throw new Exception("Could not list processes locking resource. Failed to get size of result.");
}
finally
{
RmEndSession(handle);
}
return processes;
}
}
您还可以检查是否使用此文件的任何过程,并显示您必须关闭的程序列表,才能像安装程序一样继续。
if not locked then
open and update file
使用Interop使用,您可以使用.NET FILESTREAM类方法锁定并解锁:
filestream.lock
http://msdn.microsoft.com/en-us/library/system.io.filestream.lock.aspx filestream.unlockhttp://msdn.microsoft.com/en-us/library/system.io.filestream.unlock.aspx
public static string GetFileProcessName(string filePath)
{
Process[] procs = Process.GetProcesses();
string fileName = Path.GetFileName(filePath);
foreach (Process proc in procs)
{
if (proc.MainWindowHandle != new IntPtr(0) && !proc.HasExited)
{
ProcessModule[] arr = new ProcessModule[proc.Modules.Count];
foreach (ProcessModule pm in proc.Modules)
{
if (pm.ModuleName == fileName)
return proc.ProcessName;
}
}
}
return null;
}
usage:
public static bool TryOpen(string path,
FileMode fileMode,
FileAccess fileAccess,
FileShare fileShare,
TimeSpan timeout,
out Stream stream)
{
var endTime = DateTime.Now + timeout;
while (DateTime.Now < endTime)
{
if (TryOpen(path, fileMode, fileAccess, fileShare, out stream))
return true;
}
stream = null;
return false;
}
public static bool TryOpen(string path,
FileMode fileMode,
FileAccess fileAccess,
FileShare fileShare,
out Stream stream)
{
try
{
stream = File.Open(path, fileMode, fileAccess, fileShare);
return true;
}
catch (IOException e)
{
if (!FileIsLocked(e))
throw;
stream = null;
return false;
}
}
private const uint HRFileLocked = 0x80070020;
private const uint HRPortionOfFileLocked = 0x80070021;
private static bool FileIsLocked(IOException ioException)
{
var errorCode = (uint)Marshal.GetHRForException(ioException);
return errorCode == HRFileLocked || errorCode == HRPortionOfFileLocked;
}
private void Sample(string filePath)
{
Stream stream = null;
try
{
var timeOut = TimeSpan.FromSeconds(1);
if (!TryOpen(filePath,
FileMode.Open,
FileAccess.ReadWrite,
FileShare.ReadWrite,
timeOut,
out stream))
return;
// Use stream...
}
finally
{
if (stream != null)
stream.Close();
}
}
您可以通过Interop在您感兴趣的文件区域上拨打lockfile。这不会引发例外,如果成功,您将在文件的该部分上锁定(由您的流程持有),锁将被保留,直到您致电unlockfile
或您的过程死亡。
到两行之间,另一个过程可以轻松锁定文件,从而使您与试图避免的相同问题开始:异常。
,无论如何,您会知道问题是暂时的,并在以后重试。 (例如,您可以编写一个线程,如果尝试写作时遇到锁,请继续重试直到锁定为止。) 另一方面,IOException本身并不足够具体,即锁定是IO失败的原因。可能不是临时的原因。
您可以通过先尝试阅读或锁定该文件是否锁定文件。请请参见我的答案,以获取更多信息。
same的东西,但在powershell中