我有一个定期写入本地磁盘文件的Delphi应用程序。有时它无法访问该文件 - 尝试打开时会导致共享冲突。在短暂的延迟之后重试是所有需要的，但是当它发生时，我想报告阻止访问的过程。
当我的程序发生共享冲突以枚举正在使用的所有文件句柄，检查文件名，以及它是否与我的数据文件的名称匹配时，检索与该句柄关联的进程名称是否可行？
一些示例代码会很好。
答案 0 :(得分：12)
你基本上有两种方式
简单方法
如果您使用的是Windows Vista或更新版本，请尝试使用IFileIsInUse界面
艰难的方式
如果您需要与Windows XP，Vista，7等兼容的方法。然后使用NtQuerySystemInformation，NtQueryInformationFile和NtQueryObject函数。
这些是继续进行的步骤
PROCESS_DUP_HANDLE real句柄。注1：此方法的棘手部分是基于句柄解析文件名。函数NtQueryInformationFile在某些场景（系统句柄和其他场景）中挂起，防止整个应用程序挂起的解决方法是从单独的线程调用该函数。
注2：存在另一个函数，如GetFileInformationByHandleEx和GetFinalPathNameByHandle来解析句柄的文件名。但两者都存在，因为在这种情况下Windows访问和更好地使用IFileIsInUse。
检查在Delphi 2007，XE2和Windows XP和7中测试的此示例应用程序。从这里您可以采取一些想法来解决您的问题。
注意：函数GetProcessIdUsingFile仅比较文件的名称（不是路径）。
{$APPTYPE CONSOLE}
uses
Windows,
SysUtils;
const
SystemHandleInformation = $10;
STATUS_SUCCESS = $00000000;
FileNameInformation = 9;
ObjectNameInformation = 1;
type
SYSTEM_HANDLE=packed record
uIdProcess:ULONG;
ObjectType:UCHAR;
Flags :UCHAR;
Handle :Word;
pObject :Pointer;
GrantedAccess:ACCESS_MASK;
end;
SYSTEM_HANDLE_ARRAY = Array[0..0] of SYSTEM_HANDLE;
SYSTEM_HANDLE_INFORMATION=packed record
uCount:ULONG;
Handles:SYSTEM_HANDLE_ARRAY;
end;
PSYSTEM_HANDLE_INFORMATION=^SYSTEM_HANDLE_INFORMATION;
NT_STATUS = Cardinal;
PFILE_NAME_INFORMATION = ^FILE_NAME_INFORMATION;
FILE_NAME_INFORMATION = packed record
FileNameLength: ULONG;
FileName: array [0..MAX_PATH - 1] of WideChar;
end;
PUNICODE_STRING = ^TUNICODE_STRING;
TUNICODE_STRING = packed record
Length : WORD;
MaximumLength : WORD;
Buffer : array [0..MAX_PATH - 1] of WideChar;
end;
POBJECT_NAME_INFORMATION = ^TOBJECT_NAME_INFORMATION;
TOBJECT_NAME_INFORMATION = packed record
Name : TUNICODE_STRING;
end;
PIO_STATUS_BLOCK = ^IO_STATUS_BLOCK;
IO_STATUS_BLOCK = packed record
Status: NT_STATUS;
Information: DWORD;
end;
PGetFileNameThreadParam = ^TGetFileNameThreadParam;
TGetFileNameThreadParam = packed record
hFile : THandle;
Result : NT_STATUS;
FileName : array [0..MAX_PATH - 1] of AnsiChar;
end;
function NtQueryInformationFile(FileHandle: THandle;
IoStatusBlock: PIO_STATUS_BLOCK; FileInformation: Pointer;
Length: DWORD; FileInformationClass: DWORD): NT_STATUS;
stdcall; external 'ntdll.dll';
function NtQueryObject(ObjectHandle: THandle;
ObjectInformationClass: DWORD; ObjectInformation: Pointer;
ObjectInformationLength: ULONG;
ReturnLength: PDWORD): NT_STATUS; stdcall; external 'ntdll.dll';
function NtQuerySystemInformation(SystemInformationClass: DWORD; SystemInformation: Pointer; SystemInformationLength: ULONG; ReturnLength: PULONG): NT_STATUS; stdcall; external 'ntdll.dll' name 'NtQuerySystemInformation';
function GetFileNameHandleThr(Data: Pointer): DWORD; stdcall;
var
dwReturn: DWORD;
FileNameInfo: FILE_NAME_INFORMATION;
ObjectNameInfo: TOBJECT_NAME_INFORMATION;
IoStatusBlock: IO_STATUS_BLOCK;
pThreadParam: TGetFileNameThreadParam;
begin
ZeroMemory(@FileNameInfo, SizeOf(FILE_NAME_INFORMATION));
pThreadParam := PGetFileNameThreadParam(Data)^;
Result := NtQueryInformationFile(pThreadParam.hFile, @IoStatusBlock, @FileNameInfo, MAX_PATH * 2, FileNameInformation);
if Result = STATUS_SUCCESS then
begin
Result := NtQueryObject(pThreadParam.hFile, ObjectNameInformation, @ObjectNameInfo, MAX_PATH * 2, @dwReturn);
if Result = STATUS_SUCCESS then
begin
pThreadParam.Result := Result;
WideCharToMultiByte(CP_ACP, 0, @ObjectNameInfo.Name.Buffer[ObjectNameInfo.Name.MaximumLength - ObjectNameInfo.Name.Length], ObjectNameInfo.Name.Length, @pThreadParam.FileName[0], MAX_PATH, nil, nil);
end
else
begin
pThreadParam.Result := STATUS_SUCCESS;
Result := STATUS_SUCCESS;
WideCharToMultiByte(CP_ACP, 0, @FileNameInfo.FileName[0], IoStatusBlock.Information, @pThreadParam.FileName[0], MAX_PATH, nil, nil);
end;
end;
PGetFileNameThreadParam(Data)^ := pThreadParam;
ExitThread(Result);
end;
function GetFileNameHandle(hFile: THandle): String;
var
lpExitCode: DWORD;
pThreadParam: TGetFileNameThreadParam;
hThread: THandle;
begin
Result := '';
ZeroMemory(@pThreadParam, SizeOf(TGetFileNameThreadParam));
pThreadParam.hFile := hFile;
hThread := CreateThread(nil, 0, @GetFileNameHandleThr, @pThreadParam, 0, PDWORD(nil)^);
if hThread <> 0 then
try
case WaitForSingleObject(hThread, 100) of
WAIT_OBJECT_0:
begin
GetExitCodeThread(hThread, lpExitCode);
if lpExitCode = STATUS_SUCCESS then
Result := pThreadParam.FileName;
end;
WAIT_TIMEOUT:
TerminateThread(hThread, 0);
end;
finally
CloseHandle(hThread);
end;
end;
//get the pid of the process which had open the specified file
function GetProcessIdUsingFile(const TargetFileName:string): DWORD;
var
hProcess : THandle;
hFile : THandle;
ReturnLength: DWORD;
SystemInformationLength : DWORD;
Index : Integer;
pHandleInfo : PSYSTEM_HANDLE_INFORMATION;
hQuery : THandle;
FileName : string;
begin
Result:=0;
pHandleInfo := nil;
ReturnLength := 1024;
pHandleInfo := AllocMem(ReturnLength);
hQuery := NTQuerySystemInformation(DWORD(SystemHandleInformation), pHandleInfo, 1024, @ReturnLength);
if ReturnLength<>0 then
begin
FreeMem(pHandleInfo);
SystemInformationLength := ReturnLength;
pHandleInfo := AllocMem(ReturnLength+1024);
hQuery := NTQuerySystemInformation(DWORD(SystemHandleInformation), pHandleInfo, SystemInformationLength, @ReturnLength);//Get the list of handles
end
else
RaiseLastOSError;
try
if(hQuery = STATUS_SUCCESS) then
begin
for Index:=0 to pHandleInfo^.uCount-1 do
if pHandleInfo.Handles[Index].ObjectType=28 then
begin
hProcess := OpenProcess(PROCESS_DUP_HANDLE, FALSE, pHandleInfo.Handles[Index].uIdProcess);
if(hProcess <> INVALID_HANDLE_VALUE) then
begin
try
if not DuplicateHandle(hProcess, pHandleInfo.Handles[Index].Handle,GetCurrentProcess(), @hFile, 0 ,FALSE, DUPLICATE_SAME_ACCESS) then
hFile := INVALID_HANDLE_VALUE;
finally
CloseHandle(hProcess);
end;
if (hFile<>INVALID_HANDLE_VALUE) then
begin
try
FileName:=GetFileNameHandle(hFile);
finally
CloseHandle(hFile);
end;
end
else
FileName:='';
//Writeln(FileName);
if CompareText(ExtractFileName(FileName), TargetFileName)=0 then
Result:=pHandleInfo.Handles[Index].uIdProcess;
end;
end;
end;
finally
if pHandleInfo<>nil then
FreeMem(pHandleInfo);
end;
end;
function SetDebugPrivilege: Boolean;
var
TokenHandle: THandle;
TokenPrivileges : TTokenPrivileges;
begin
Result := false;
if OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES or TOKEN_QUERY, TokenHandle) then
begin
if LookupPrivilegeValue(nil, PChar('SeDebugPrivilege'), TokenPrivileges.Privileges[0].Luid) then
begin
TokenPrivileges.PrivilegeCount := 1;
TokenPrivileges.Privileges[0].Attributes := SE_PRIVILEGE_ENABLED;
Result := AdjustTokenPrivileges(TokenHandle, False,
TokenPrivileges, 0, PTokenPrivileges(nil)^, PDWord(nil)^);
end;
end;
end;
begin
try
SetDebugPrivilege;
Writeln('Processing');
Writeln(GetProcessIdUsingFile('MyFile.txt'));
Writeln('Done');
except
on E:Exception do
Writeln(E.Classname, ': ', E.Message);
end;
Readln;
end.
答案 1 :(得分：2)
使用NtQuerySystemInformation，您可以列出所有进程的所有打开句柄，然后您可以使用此函数获取文件名
function NtQueryInformationFile(FileHandle: THandle;IoStatusBlock: PIO_STATUS_BLOCK; FileInformation: Pointer;Length: DWORD; FileInformationClass: DWORD): NTSTATUS;stdcall; external 'ntdll.dll';
function GetFileNameFromHandle(const hFile: THandle): string;
var
IO_STATUSBLOCK:IO_STATUS_BLOCK;
FileNameInfo:FILE_NAME_INFORMATION;
szFile:String;
begin
FillChar(FileNameInfo.FileName,SizeOf(FileNameInfo.FileName),0);
NtQueryInformationFile(hFile,@IO_STATUSBLOCK,@FileNameInfo,500,9);
szFile:=WideCharToString(FileNameInfo.fileName);
CloseHandle(hFile);
Result:=szFile;
end;
如果这是您的文件而非提出消息......
答案 2 :(得分：0)
您可以在此处找到JEDI项目的IFileIsInUse接口的源示例：https://svn.code.sf.net/p/jedi-apilib/code/jwapi/trunk/Examples/FileIsInUse/Client/FileIsInUseClientExample.dpr
{******************************************************************************}
{ JEDI FileIsInUse Example Project }
{ http://jedi-apilib.sourceforge.net }
{ }
{ Obtained through: Joint Endeavour of Delphi Innovators (Project JEDI) }
{ }
{ Author(s): Christian Wimmer }
{ }
{ Description: Shows how to use the IFileIsInUse API }
{ }
{ Preparations: JWA must be ready to use. }
{ Requires at least Windows Vista }
{ }
{ Version history: 14th November 2010 initial release }
{ }
{ No license. Use this example with no warranty at all and on your own risk. }
{ This example is just for learning purposes and should not be used in }
{ productive environments. }
{ The code has surely some errors that need to be fixed. In such a case }
{ you can contact the author(s) through the JEDI API hompage, the mailinglist }
{ or via the article link. }
{ }
{******************************************************************************}
program FileIsInUseClientExample;
{Define this switch to use the definition of the IFileIsInUse interface from
the JEDI API units.
Undefine it, to use it from the file here.
}
{.$DEFINE JWA_BUILTIN_IFILEISINUSE}
uses
ComObj,
ActiveX,
SysUtils,
JwaWinType,
JwaWinUser
{$IFDEF JWA_BUILTIN_IFILEISINUSE}
,JwaShlObj
{$ENDIF JWA_BUILTIN_IFILEISINUSE}
;
{$IFNDEF JWA_BUILTIN_IFILEISINUSE}
{$ALIGN 4}
const
IID_IFileIsInUse: TGUID = (
D1:$64a1cbf0; D2:$3a1a; D3:$4461; D4:($91,$58,$37,$69,$69,$69,$39,$50));
type
tagFILE_USAGE_TYPE = (
FUT_PLAYING = 0,
FUT_EDITING = 1,
FUT_GENERIC = 2
);
FILE_USAGE_TYPE = tagFILE_USAGE_TYPE;
TFileUsageType = FILE_USAGE_TYPE;
const
OF_CAP_CANSWITCHTO = $0001;
OF_CAP_CANCLOSE = $0002;
type
IFileIsInUse = interface(IUnknown)
['{64a1cbf0-3a1a-4461-9158-376969693950}']
function GetAppName(out ppszName: LPWSTR) : HRESULT; stdcall;
function GetUsage(out pfut : FILE_USAGE_TYPE) : HRESULT; stdcall;
function GetCapabilities(out pdwCapFlags : DWORD) : HRESULT; stdcall;
function GetSwitchToHWND(out phwnd : HWND) : HRESULT; stdcall;
function CloseFile() : HRESULT; stdcall;
end;
{$ENDIF JWA_BUILTIN_IFILEISINUSE}
function GetFileInUseInfo(const FileName : WideString) : IFileIsInUse;
var
ROT : IRunningObjectTable;
mFile, enumIndex, Prefix : IMoniker;
enumMoniker : IEnumMoniker;
MonikerType : LongInt;
unkInt : IInterface;
ctx : IBindCtx;
sEnumIndex, sFile : PWideChar;
begin
result := nil;
OleCheck(CreateBindCtx(0, ctx));
//
OleCheck(GetRunningObjectTable(0, ROT));
OleCheck(CreateFileMoniker(PWideChar(FileName), mFile));
OleCheck(ROT.EnumRunning(enumMoniker));
while (enumMoniker.Next(1, enumIndex, nil) = S_OK) do
begin
OleCheck(enumIndex.IsSystemMoniker(MonikerType));
if MonikerType = MKSYS_FILEMONIKER then
begin
OleCheck((EnumIndex as IMoniker).GetDisplayName(ctx, nil, sEnumIndex));
sFile := CoTaskMemAlloc(MAX_PATH);
OleCheck(mFile.GetDisplayName(ctx, nil, sFile));
if Succeeded(mFile.CommonPrefixWith(enumIndex, Prefix)) and
(mFile.IsEqual(Prefix) = S_OK) then
begin
if Succeeded(ROT.GetObject(enumIndex, unkInt)) then
begin
if Succeeded(unkInt.QueryInterface(IID_IFileIsInUse, result)) then
begin
result := unkInt as IFileIsInUse;
exit;
end;
end;
end;
end;
end;
end;
const
TFileUsageTypeStr : array[TFileUsageType] of String = (
'FUT_PLAYING (0)',
'FUT_EDITING (1)',
'FUT_GENERIC (2)');
CapStr : array[1..3] of String = (
'OF_CAP_CANSWITCHTO ($0001)',
'OF_CAP_CANCLOSE ($0002)',
'OF_CAP_CANSWITCHTO ($0001) or OF_CAP_CANCLOSE ($0002)'
);
var
FileInUse : IFileIsInUse;
pAppName : PWidechar;
Usage : TFileUsageType;
Caps : Cardinal;
WindowHandle : HWND;
Msg, S : String;
Buttons : Integer;
begin
CoInitialize(nil);
if not FileExists(ParamStr(1)) then
begin
MessageBox(0, 'Missing filename as command line parameter', '', MB_ICONERROR or MB_OK);
exit;
end;
FileInUse := GetFileInUseInfo(ParamStr(1));
if Assigned(FileInUse) then
begin
OleCheck(FileInUse.GetAppName(pAppName));
OleCheck(FileInUse.GetUsage(Usage));
OleCheck(FileInUse.GetCapabilities(Caps));
OleCheck(FileInUse.GetSwitchToHWND(WindowHandle));
Buttons := MB_OK;
if (Caps and OF_CAP_CANSWITCHTO = OF_CAP_CANSWITCHTO) then
begin
Msg := 'YES = Switch to Window? NO = Send close file; Cancel= Do nothing';
Buttons := MB_YESNOCANCEL;
end;
S := Format('AppName: %s'#13#10'Usage: %s'#13#10'Caps: %s'#13#10'Hwnd: %d'#13#10+Msg,
[WideString(pAppName), TFileUsageTypeStr[Usage], CapStr[Caps], WindowHandle]);
case MessageBox(0, PChar(S), '', MB_ICONINFORMATION or Buttons) of
IDYES:
begin
SetForegroundWindow(WindowHandle);
Sleep(2000); //allows the window to be displayed in front; otherwise IDE will be shown
end;
IDNO:
begin
OleCheck(FileInUse.CloseFile);
end;
end;
CoTaskMemFree(pAppName);
end;
end.