CreateProcess问题求教...

Question

为什么我用CreateProcess创建一个进程，执行一个dos命令（就一个dir/s,正常大约1分钟)
用 GetExitCodeProcess来获得进程结束代号，要等四五分钟才结束，
而用WaitForSingleObject(hProc, INFINITE)干脆就无限期等待了
procedure TForm1.Button2Click(Sender: TObject);
var
  pi: Process_Information;
  ExitCode: DWord;
  si: TStartUPINFO;
  Ti: integer;
begin
  FillChar(si, Sizeof(si), 0);
  si.cb := sizeof(si);
  si.wShowWindow := SW_HIDE;
  si.dwFlags := STARTF_USESHOWWINDOW;
 if CreateProcess(nil, PChar('C:\BB.bat'), nil, nil, True, NORMAL_PRIORITY_CLASS,
    nil, PChar('C:\'), si, pi) then
 begin
  WaitForSingleObject(pi.hProcess, 1000);
  {repeat
    GetExitCodeProcess(pi.hProcess, INFINITE);
  until ExitCode <> STILL_ACTIVE;}
  closeHandle(pi.hProcess);
  closeHandle(pi.hThread);
 end;
 
但是如果用下面的代码，却很快就返回
function ExcuteCmd(const CmdLine, CmdDir: string; var RetStr: string):Boolean;
var
  hPipe,hRead1, hWrite1, hRead2, hWrite2: THandle;
  si: TStartupInfo;
  sa: SECURITY_ATTRIBUTES;
  pi: Process_Information;
  ExitCode: DWord;
  ByteCount: Integer;
  dwBytesRead,dwTotal, dwLeft: Dword;
  Buf: PChar;
  bSucc:  Boolean;
const
  BufSize = 5120;begin
  Result := False;
  FillChar(si, Sizeof(si), 0);
  sa.nLength := sizeOf(sa);
  sa.lpSecurityDescriptor := nil;
  sa.bInheritHandle := True;
  CreatePipe(hRead1, hWrite1, @sa, 0);
  CreatePipe(hRead2, hWrite2, @sa, 0);
  si.cb := sizeof(si);
  si.wShowWindow := SW_HIDE;
  si.dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
  si.hStdInput := hRead1;
  si.hStdOutput := hWrite2;
  Buf := StrAlloc(BufSize);
  if CreateProcess(nil, PChar(CmdLine), nil, nil, True, NORMAL_PRIORITY_CLASS,
    nil, PChar(CmdDir), si, pi) then
  begin
    Result := True;
    repeat
      GetExitCodeProcess(pi.hProcess, ExitCode);
      while True do
      begin
        PeekNamedPipe(hRead2, Buf, BufSize, @dwBytesRead, @dwTotal, @dwLeft);
        if dwBytesRead = 0 then Break;
        ZeroMemory(Buf, BufSize);
        ReadFile(hRead2, Buf^, BufSize, dwBytesRead, nil);
        ByteCount := ByteCount + dwBytesRead;
        RetStr := RetStr + StrPas(Buf);
      end;
    until ExitCode <> STILL_ACTIVE;
  end;
  CloseHandle(hRead1);
  CloseHandle(hRead2);
  CloseHandle(hWrite1);
  CloseHandle(hWrite2);
  CloseHandle(pi.hProcess);
  CloseHandle(pi.hThread);
  StrDispose(Buf)
end;请赐教...

Answer 1

//我自己写的，我自用没问题
//执行处部可执行文件
Function LaunchApp(pExePath,WorkDir:String;ShowWindow,WaitFlag:Boolean):Boolean;
var ExePath : array[0..512] of char;
    StartupInfo:TStartupInfo;
    ProcessInfo:TProcessInformation;
begin
  StrPCopy(exePath, pExePath);
  FillChar(StartupInfo,Sizeof(StartupInfo),#0);
  StartupInfo.cb := Sizeof(StartupInfo);
  StartupInfo.dwFlags := STARTF_USESHOWWINDOW;
  if ShowWindow then
    StartupInfo.wShowWindow := 1
  else
    StartupInfo.wShowWindow := 0;
  if not CreateProcess(nil,
                      ExePath,
                      nil,
                      nil,
                      false,
                      CREATE_NEW_CONSOLE or
                      NORMAL_PRIORITY_CLASS,
                      nil,
                      nil,
                      StartupInfo,
                      ProcessInfo) then  begin
    Result:=False;
    Exit;
  end else begin
    if WaitFlag then
      WaitforSingleObject(ProcessInfo.hProcess,INFINITE);
    Result:=True;
  end;
end;