为什么一个HANDLE不能用于WriteConsoleInput,但适用于WriteFile?

时间:2013-07-15 08:58:35

标签: c++ c winapi user32

所以我试图修改Microsoft提供的代码(here)以使用WriteConsoleInput而不是WriteFile,但是它说句柄无效(我认为这是非常愚蠢的东西),就像最初创建句柄或其他东西。

所以我的问题是,WriteConsoleInput所需的句柄和WriteFile的句柄之间有什么区别?

WriteConsoleInput

WriteFile

我猜它与CreateFile创建的HANDLE的权限标志相比,与CreateProcess / CreatePipe / DuplicateHandle进程创建的继承句柄相比。

我认为如果你能看到问题会更容易,所以这是我的完整解决方案(使用Visual Studio 2012)包括子应用程序和父应用程序。

ConsoleRedir on GitHub

作为一个注释,我需要子应用程序使用ReadConsoleInput,这是我沮丧的源头。

原始方法:

/////////////////////////////////////////////////////////////////////// 
// GetAndSendInputThreadOrig
// Thread procedure that monitors the console for input and sends input
// to the child process through the input pipe.
// This thread ends when the child application exits.
// Original from http://support.microsoft.com/kb/190351
/////////////////////////////////////////////////////////////////////// 
DWORD WINAPI GetAndSendInputThreadOrig(LPVOID lpvThreadParam)
{
    CHAR read_buff[256];
    DWORD nBytesRead,nBytesWrote;
    HANDLE hPipeWrite = (HANDLE)lpvThreadParam;

    // Get input from our console and send it to child through the pipe.
    while (bRunThread)
    {
        if(!ReadConsole(hStdIn,read_buff,1,&nBytesRead,NULL))
            DisplayError("ReadConsole");

        read_buff[nBytesRead] = '\0'; // Follow input with a NULL.

        if (!WriteFile(hPipeWrite,read_buff,nBytesRead,&nBytesWrote,NULL))
        {
            if (GetLastError() == ERROR_NO_DATA)
                break; // Pipe was closed (normal exit path).
            else
                DisplayError("WriteFile");
        }
    }

    return 1;
}

我的修改版本(必须构建按键):

/////////////////////////////////////////////////////////////////////// 
// GetAndSendInputThread
// Thread procedure that monitors the console for input and sends input
// to the child process through the input pipe.
// This thread ends when the child application exits.
/////////////////////////////////////////////////////////////////////// 
DWORD WINAPI GetAndSendInputThread(LPVOID lpvThreadParam)
{
    CHAR read_buff[256];
    DWORD nBytesWrote;
    HANDLE hPipeWrite = (HANDLE)lpvThreadParam;

    // Get input from our console and send it to child through the pipe.
    while (bRunThread)
    {
        INPUT_RECORD inputRecords[4];
        // Build a keyboard event, press '?' and then press RETURN
        inputRecords[0].EventType = KEY_EVENT;
        inputRecords[0].Event.KeyEvent.bKeyDown = TRUE;
        inputRecords[0].Event.KeyEvent.uChar.UnicodeChar = '?';
        inputRecords[1].EventType = KEY_EVENT;
        inputRecords[1].Event.KeyEvent.bKeyDown = FALSE;
        inputRecords[1].Event.KeyEvent.uChar.UnicodeChar = '?';
        inputRecords[2].EventType = KEY_EVENT;
        inputRecords[2].Event.KeyEvent.bKeyDown = TRUE;
        inputRecords[2].Event.KeyEvent.dwControlKeyState = 0;
        inputRecords[2].Event.KeyEvent.uChar.UnicodeChar = '\r';
        inputRecords[2].Event.KeyEvent.wRepeatCount = 1;
        inputRecords[2].Event.KeyEvent.wVirtualKeyCode = VK_RETURN;
        inputRecords[2].Event.KeyEvent.wVirtualScanCode = MapVirtualKey(VK_RETURN, MAPVK_VK_TO_VSC);
        inputRecords[3].EventType = KEY_EVENT;
        inputRecords[3].Event.KeyEvent.bKeyDown = FALSE;
        inputRecords[3].Event.KeyEvent.dwControlKeyState = 0;
        inputRecords[3].Event.KeyEvent.uChar.UnicodeChar = '\r';
        inputRecords[3].Event.KeyEvent.wRepeatCount = 1;
        inputRecords[3].Event.KeyEvent.wVirtualKeyCode = VK_RETURN;
        inputRecords[3].Event.KeyEvent.wVirtualScanCode = MapVirtualKey(VK_RETURN, MAPVK_VK_TO_VSC);


        if (!WriteConsoleInput(hPipeWrite,inputRecords,sizeof(inputRecords) / sizeof(*inputRecords),&nBytesWrote))
        {
            if (GetLastError() == ERROR_NO_DATA)
                break; // Pipe was closed (normal exit path).
            else
                DisplayError("WriteConsoleInput");
        }
    }

    return 1;
}

1 个答案:

答案 0 :(得分:2)

WriteConsoleInput要求句柄是“控制台输入缓冲区的句柄”。 (问题中链接页面中handle输入参数说明中的第一句)。

您需要使用GetStdHandle的句柄来获得合适的句柄。

WriteConsoleInput仅适用于控制台的直接句柄,而不是重定向的管道或类似控件。