清除屏幕

在控制台应用程序中,可以使用四种方法清除屏幕。

示例 1

提示

对于所有新的开发,建议使用 虚拟终端序列 来执行此方法。 有关详细信息,请参阅 经典控制台 api 与虚拟终端序列 的讨论。

第一种方法是将应用程序设置为虚拟终端输出序列,然后调用 "清除屏幕" 命令。

#include <windows.h>

int main(void)
{
    HANDLE hStdOut;

    hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);

    // Fetch existing console mode so we correctly add a flag and not turn off others
    DWORD mode = 0;
    if (!GetConsoleMode(hStdOut, &mode))
    {
        return ::GetLastError();
    }

    // Hold original mode to restore on exit to be cooperative with other command-line apps.
    const DWORD originalMode = mode;
    mode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;

    // Try to set the mode.
    if (!SetConsoleMode(hStdOut, mode))
    {
        return ::GetLastError();
    }

    // Write the sequence for clearing the display.
    DWORD written = 0;
    PCWSTR sequence = L"\x1b[2J";
    if (!WriteConsoleW(hStdOut, sequence, (DWORD)wcslen(sequence), &written, NULL))
    {
        // If we fail, try to restore the mode on the way out.
        SetConsoleMode(hStdOut, originalMode);
        return ::GetLastError();
    }

    // To also clear the scroll back, emit L"\x1b[3J" as well.
    // 2J only clears the visible window and 3J only clears the scroll back.

    // Restore the mode on the way out to be nice to other command-line applications.
    SetConsoleMode(hStdOut, originalMode);

    return 0;
}

可以在显示的 " 擦除" 的虚拟终端序列文档中找到此命令的其他变体。

示例 2

第二种方法是编写一个函数,用于滚动屏幕或缓冲区的内容并为显示的空间设置填充。

这与命令提示符的行为匹配 cmd.exe

#include <windows.h>

void cls(HANDLE hConsole)
{
    CONSOLE_SCREEN_BUFFER_INFO csbi;
    SMALL_RECT scrollRect;
    COORD scrollTarget;
    CHAR_INFO fill;

    // Get the number of character cells in the current buffer.
    if (!GetConsoleScreenBufferInfo(hConsole, &csbi))
    {
        return;
    }

    // Scroll the rectangle of the entire buffer.
    scrollRect.Left = 0;
    scrollRect.Top = 0;
    scrollRect.Right = csbi.dwSize.X;
    scrollRect.Bottom = csbi.dwSize.Y;

    // Scroll it upwards off the top of the buffer with a magnitude of the entire height.
    scrollTarget.X = 0;
    scrollTarget.Y = (SHORT)(0 - csbi.dwSize.Y);

    // Fill with empty spaces with the buffer's default text attribute.
    fill.Char.UnicodeChar = TEXT(' ');
    fill.Attributes = csbi.wAttributes;

    // Do the scroll
    ScrollConsoleScreenBuffer(hConsole, &scrollRect, NULL, scrollTarget, &fill);

    // Move the cursor to the top left corner too.
    csbi.dwCursorPosition.X = 0;
    csbi.dwCursorPosition.Y = 0;

    SetConsoleCursorPosition(hConsole, csbi.dwCursorPosition);
}

int main(void)
{
    HANDLE hStdout;

    hStdout = GetStdHandle(STD_OUTPUT_HANDLE);

    cls(hStdout);

    return 0;
}

示例 3

第三种方法是使用 FillConsoleOutputCharacterFillConsoleOutputAttribute 函数编写函数以编程方式清除屏幕。

下面的示例代码演示了此方法。

#include <windows.h>

void cls(HANDLE hConsole)
{
    COORD coordScreen = { 0, 0 };    // home for the cursor
    DWORD cCharsWritten;
    CONSOLE_SCREEN_BUFFER_INFO csbi;
    DWORD dwConSize;

    // Get the number of character cells in the current buffer.
    if (!GetConsoleScreenBufferInfo(hConsole, &csbi))
    {
        return;
    }

    dwConSize = csbi.dwSize.X * csbi.dwSize.Y;

    // Fill the entire screen with blanks.
    if (!FillConsoleOutputCharacter(hConsole,        // Handle to console screen buffer
                                    (TCHAR)' ',      // Character to write to the buffer
                                    dwConSize,       // Number of cells to write
                                    coordScreen,     // Coordinates of first cell
                                    &cCharsWritten)) // Receive number of characters written
    {
        return;
    }

    // Get the current text attribute.
    if (!GetConsoleScreenBufferInfo(hConsole, &csbi))
    {
        return;
    }

    // Set the buffer's attributes accordingly.
    if (!FillConsoleOutputAttribute(hConsole,         // Handle to console screen buffer
                                    csbi.wAttributes, // Character attributes to use
                                    dwConSize,        // Number of cells to set attribute
                                    coordScreen,      // Coordinates of first cell
                                    &cCharsWritten))  // Receive number of characters written
    {
        return;
    }

    // Put the cursor at its home coordinates.
    SetConsoleCursorPosition(hConsole, coordScreen);
}

int main(void)
{
    HANDLE hStdout;

    hStdout = GetStdHandle(STD_OUTPUT_HANDLE);

    cls(hStdout);

    return 0;
}