使用高级输入和输出函数

重要

本文档介绍控制台平台功能，该功能已不再是生态系统蓝图的一部分。 我们不建议在新产品中使用此内容，但我们未来将无限期支持现有使用。 我们的首选最新解决方案侧重于虚拟终端序列，以实现跨平台方案中的最大兼容性。 有关此设计决策的详细信息，请参阅经典控制台与虚拟终端文档。

下面的示例对控制台 I/O 使用高级控制台 I/O 函数。 有关高级控制台 I/O 函数的详细信息，请参阅高级控制台 I/O。

该示例假定默认 I/O 模式最初对 ReadFile 和 WriteFile 函数的首次调用生效。 然后，更改输入模式以切换对 ReadFile 和 WriteFile 的第二次调用的脱机输入模式和回显输入模式。 SetConsoleTextAttribute 函数用于设置随后写入的文本显示的颜色。 在退出之前，程序将还原原始控制台输入模式和颜色属性。

禁用行输入模式时，使用示例的 NewLine 函数。 它通过将光标位置移动到下一行第一个单元格来处理回车。 如果光标已位于控制台屏幕缓冲区的最后一行，则控制台屏幕缓冲区的内容将向上滚动一行。

#include <windows.h>

void NewLine(void);
void ScrollScreenBuffer(HANDLE, INT);

HANDLE hStdout, hStdin;
CONSOLE_SCREEN_BUFFER_INFO csbiInfo;

int main(void)
{
    LPSTR lpszPrompt1 = "Type a line and press Enter, or q to quit: ";
    LPSTR lpszPrompt2 = "Type any key, or q to quit: ";
    CHAR chBuffer[256];
    DWORD cRead, cWritten, fdwMode, fdwOldMode;
    WORD wOldColorAttrs;

    // Get handles to STDIN and STDOUT.

    hStdin = GetStdHandle(STD_INPUT_HANDLE);
    hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
    if (hStdin == INVALID_HANDLE_VALUE ||
        hStdout == INVALID_HANDLE_VALUE)
    {
        MessageBox(NULL, TEXT("GetStdHandle"), TEXT("Console Error"),
            MB_OK);
        return 1;
    }

    // Save the current text colors.

    if (! GetConsoleScreenBufferInfo(hStdout, &csbiInfo))
    {
        MessageBox(NULL, TEXT("GetConsoleScreenBufferInfo"),
            TEXT("Console Error"), MB_OK);
        return 1;
    }

    wOldColorAttrs = csbiInfo.wAttributes;

    // Set the text attributes to draw red text on black background.

    if (! SetConsoleTextAttribute(hStdout, FOREGROUND_RED |
            FOREGROUND_INTENSITY))
    {
        MessageBox(NULL, TEXT("SetConsoleTextAttribute"),
            TEXT("Console Error"), MB_OK);
        return 1;
    }

    // Write to STDOUT and read from STDIN by using the default
    // modes. Input is echoed automatically, and ReadFile
    // does not return until a carriage return is typed.
    //
    // The default input modes are line, processed, and echo.
    // The default output modes are processed and wrap at EOL.

    while (1)
    {
        if (! WriteFile(
            hStdout,               // output handle
            lpszPrompt1,           // prompt string
            lstrlenA(lpszPrompt1), // string length
            &cWritten,             // bytes written
            NULL) )                // not overlapped
        {
            MessageBox(NULL, TEXT("WriteFile"), TEXT("Console Error"),
                MB_OK);
            return 1;
        }

        if (! ReadFile(
            hStdin,    // input handle
            chBuffer,  // buffer to read into
            255,       // size of buffer
            &cRead,    // actual bytes read
            NULL) )    // not overlapped
        break;
        if (chBuffer[0] == 'q') break;
    }

    // Turn off the line input and echo input modes

    if (! GetConsoleMode(hStdin, &fdwOldMode))
    {
       MessageBox(NULL, TEXT("GetConsoleMode"), TEXT("Console Error"),
           MB_OK);
       return 1;
    }

    fdwMode = fdwOldMode &
        ~(ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT);
    if (! SetConsoleMode(hStdin, fdwMode))
    {
       MessageBox(NULL, TEXT("SetConsoleMode"), TEXT("Console Error"),
           MB_OK);
       return 1;
    }

    // ReadFile returns when any input is available.  
    // WriteFile is used to echo input.

    NewLine();

    while (1)
    {
        if (! WriteFile(
            hStdout,               // output handle
            lpszPrompt2,           // prompt string
            lstrlenA(lpszPrompt2), // string length
            &cWritten,             // bytes written
            NULL) )                // not overlapped
        {
            MessageBox(NULL, TEXT("WriteFile"), TEXT("Console Error"),
                MB_OK);
            return 1;
        }

        if (! ReadFile(hStdin, chBuffer, 1, &cRead, NULL))
            break;
        if (chBuffer[0] == '\r')
            NewLine();
        else if (! WriteFile(hStdout, chBuffer, cRead,
            &cWritten, NULL)) break;
        else
            NewLine();
        if (chBuffer[0] == 'q') break;
    }

    // Restore the original console mode.

    SetConsoleMode(hStdin, fdwOldMode);

    // Restore the original text colors.

    SetConsoleTextAttribute(hStdout, wOldColorAttrs);

    return 0;
}

// The NewLine function handles carriage returns when the processed
// input mode is disabled. It gets the current cursor position
// and resets it to the first cell of the next row.

void NewLine(void)
{
    if (! GetConsoleScreenBufferInfo(hStdout, &csbiInfo))
    {
        MessageBox(NULL, TEXT("GetConsoleScreenBufferInfo"),
            TEXT("Console Error"), MB_OK);
        return;
    }

    csbiInfo.dwCursorPosition.X = 0;

    // If it is the last line in the screen buffer, scroll
    // the buffer up.

    if ((csbiInfo.dwSize.Y-1) == csbiInfo.dwCursorPosition.Y)
    {
        ScrollScreenBuffer(hStdout, 1);
    }

    // Otherwise, advance the cursor to the next line.

    else csbiInfo.dwCursorPosition.Y += 1;

    if (! SetConsoleCursorPosition(hStdout,
        csbiInfo.dwCursorPosition))
    {
        MessageBox(NULL, TEXT("SetConsoleCursorPosition"),
            TEXT("Console Error"), MB_OK);
        return;
    }
}

void ScrollScreenBuffer(HANDLE h, INT x)
{
    SMALL_RECT srctScrollRect, srctClipRect;
    CHAR_INFO chiFill;
    COORD coordDest;

    srctScrollRect.Left = 0;
    srctScrollRect.Top = 1;
    srctScrollRect.Right = csbiInfo.dwSize.X - (SHORT)x;
    srctScrollRect.Bottom = csbiInfo.dwSize.Y - (SHORT)x;

    // The destination for the scroll rectangle is one row up.

    coordDest.X = 0;
    coordDest.Y = 0;

    // The clipping rectangle is the same as the scrolling rectangle.
    // The destination row is left unchanged.

    srctClipRect = srctScrollRect;

    // Set the fill character and attributes.

    chiFill.Attributes = FOREGROUND_RED|FOREGROUND_INTENSITY;
    chiFill.Char.AsciiChar = (char)' ';

    // Scroll up one line.

    ScrollConsoleScreenBuffer(
        h,               // screen buffer handle
        &srctScrollRect, // scrolling rectangle
        &srctClipRect,   // clipping rectangle
        coordDest,       // top left destination cell
        &chiFill);       // fill character and color
}