FindWindow per Handle

[Zacherl]

Kein Problem, dafür ist das Forum ja da. Folgende Variante sollte ab Windows 2000 funktionieren (auch ohne psapi.dll und mit Unterstützung von 64 bit Prozessen):

Delphi-Quellcode:

{$Z4}
type
  _PROCESSINFOCLASS = (
    ProcessBasicInformation,
    ProcessQuotaLimits,
    ProcessIoCounters,
    ProcessVmCounters,
    ProcessTimes,
    ProcessBasePriority,
    ProcessRaisePriority,
    ProcessDebugPort,
    ProcessExceptionPort,
    ProcessAccessToken,
    ProcessLdtInformation,
    ProcessLdtSize,
    ProcessDefaultHardErrorMode,
    ProcessIoPortHandlers,
    ProcessPooledUsageAndLimits,
    ProcessWorkingSetWatch,
    ProcessUserModeIOPL,
    ProcessEnableAlignmentFaultFixup,
    ProcessPriorityClass,
    ProcessWx86Information,
    ProcessHandleCount,
    ProcessAffinityMask,
    ProcessPriorityBoost,
    ProcessDeviceMap,
    ProcessSessionInformation,
    ProcessForegroundInformation,
    ProcessWow64Information,
    ProcessImageFileName,
    ProcessLUIDDeviceMapsEnabled,
    ProcessBreakOnTermination,
    ProcessDebugObjectHandle,
    ProcessDebugFlags,
    ProcessHandleTracing,
    MaxProcessInfoClass);
  PROCESSINFOCLASS = _PROCESSINFOCLASS;
  PROCESS_INFORMATION_CLASS = PROCESSINFOCLASS;
  TProcessInfoClass = PROCESSINFOCLASS;
{$Z1}

function NtQueryInformationProcess(ProcessHandle: THandle;
  ProcessInformationClass: PROCESSINFOCLASS; ProcessInformation: Pointer;
  ProcessInformationLength: ULONG; ReturnLength: PULONG): LongInt; stdcall; external 'ntdll.dll';

type
  PUNICODE_STRING = ^UNICODE_STRING;
  {$EXTERNALSYM PUNICODE_STRING}
  _UNICODE_STRING = record
    Length: USHORT;
    MaximumLength: USHORT;
    Buffer: PWideChar;
  end;
  {$EXTERNALSYM _UNICODE_STRING}
  UNICODE_STRING = _UNICODE_STRING;
  {$EXTERNALSYM UNICODE_STRING}
  PCUNICODE_STRING = ^UNICODE_STRING;
  {$EXTERNALSYM PCUNICODE_STRING}
  TUnicodeString = UNICODE_STRING;
  PUnicodeString = PUNICODE_STRING;

procedure TForm3.Button1Click(Sender: TObject);
var
  ThreadId,
  ProcessId: DWord;
  hProcess: THandle;
  Data: Pointer;
  Size: ULONG;
begin
  ThreadId := GetWindowThreadProcessId(WindowHandle, ProcessId);
  if (ThreadId <> 0) then
  begin
    hProcess := OpenProcess(PROCESS_QUERY_INFORMATION or PROCESS_VM_READ, false, ProcessId);
    if (hProcess <> 0) and (hProcess <> INVALID_HANDLE_VALUE) then
    try
      NtQueryInformationProcess(hProcess, ProcessImageFileName, nil, 0, @Size);
      GetMem(Data, Size);
      try
        if (NtQueryInformationProcess(hProcess, ProcessImageFileName, Data, Size, @Size) = 0) then
        begin
          Caption := ExtractFileName(PUNICODE_STRING(Data).Buffer);
        end;
      finally
        FreeMem(Data);
      end;
    finally
      CloseHandle(hProcess);
    end;
  end;
end;

Die Funktion ermittelt allerdings nur den Dateinamen und nicht den kompletten Pfad. Wenn du den ganzen Pfad haben willst, wird es für Systeme < Vista etwas komplizierter.

Alternativ vielleicht noch etwas sauberer über die TlHelp32 API:

Delphi-Quellcode:

procedure TForm3.Button1Click(Sender: TObject);
var
  ThreadId,
  ProcessId: DWord;
  hSnapshot: THandle;
  Process: TProcessEntry32;
begin
  ThreadId := GetWindowThreadProcessId(WindowHandle, ProcessId);
  if (ThreadId <> 0) then
  begin
    hSnapshot := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, ProcessId);
    if (hSnapshot <> 0) and (hSnapshot <> INVALID_HANDLE_VALUE) then
    try
      FillChar(Process, SizeOf(Process), #0);
      Process.dwSize := SizeOf(Process);
      if Process32First(hSnapshot, Process) then
      repeat
        if (Process.th32ProcessID = ProcessId) then
        begin
          Caption := StrPas(PChar(@Process.szExeFile[0]));
          Break;
        end;
      until not Process32Next(hSnapshot, Process);
    finally
      CloseHandle(hSnapshot);
    end;
  end;
end;