WinAPI中如何实现按钮长按连续触发功能？

我的程序中，按钮按下时计数器只会递增一次，但长按按钮时无法实现连续递增。请问该如何修改代码实现这一功能？

以下是我的示例代码：

#include <Windows.h>

HINSTANCE g_hInst;

LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
    static int n = 0;
    static HWND hEdit;
    static HWND hButton;

    switch (uMsg) {
    case WM_CREATE:
        hEdit = CreateWindow(L"EDIT", L"0", WS_CHILD | WS_VISIBLE | ES_CENTER | ES_READONLY, 100, 100, 100, 20, hWnd, (HMENU)1, g_hInst, NULL);
        hButton = CreateWindow(L"BUTTON", L"▴", WS_CHILD | WS_VISIBLE | BS_LEFT, 200 + 4, 100, 20, 20, hWnd, (HMENU)2, g_hInst, NULL);
        break;
    case WM_COMMAND: {
        HWND ctlHwnd = (HWND)lParam;
        int ctlId = LOWORD(wParam);
        int notificationCode = HIWORD(wParam);

        if (notificationCode == BN_CLICKED) {
            n++;
            wchar_t buf[40] = {0};
            wsprintf(buf, L"%d", n);
            SetWindowText(hEdit, buf);
        }
        break;
    }
    case WM_DESTROY:
        PostQuitMessage(EXIT_SUCCESS);
        break;
    default:
        return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    return 0;
}

int WINAPI WinMain(
    HINSTANCE hInst,
    HINSTANCE hPrevInst,
    LPSTR lpCmdLine,
    int iCmdShow)
{
    g_hInst = hInst;

    WNDCLASS wndClass = {
        .style = CS_HREDRAW | CS_VREDRAW,
        .lpfnWndProc = WindowProc,
        .hInstance = hInst,
        .hIcon = LoadIcon(NULL, IDI_APPLICATION),
        .hCursor = LoadCursor(NULL, IDC_ARROW),
        .hbrBackground = (HBRUSH)GetStockObject(LTGRAY_BRUSH),
        .lpszMenuName = NULL,
        .lpszClassName = L"app",
    };
    if (!RegisterClass(&wndClass)) {
        OutputDebugString(L"Failed to register window class\n");
        return EXIT_FAILURE;
    }
    if (!CreateWindow(
        L"app",
        L"Counter",
        WS_OVERLAPPEDWINDOW | WS_VISIBLE,
        0, 0,
        1280, 720,
        NULL, NULL,
        hInst, NULL))
    {
        OutputDebugString(L"Failed to create window\n");
        return EXIT_FAILURE;
    }
    MSG msg = {};
    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (int)msg.wParam;
}

问题核心在于BN_CLICKED消息仅在按钮点击（按下后松开）时触发一次，默认不会重复发送。要实现长按连续递增，需要通过定时器结合按钮的按下/松开状态来处理，具体步骤如下：

关键修改点 #

1. 给按钮添加BS_NOTIFY样式：让按钮能发送BN_PUSHED（按下）和BN_UNPUSHED（松开）通知，用于检测长按状态。
2. 添加状态记录变量：记录按钮是否被按下、定时器ID。
3. 处理按钮状态通知：按下时启动定时器并立即递增一次，松开时停止定时器。
4. 处理定时器消息：每隔固定间隔触发计数器递增。

修改后的完整代码 #

#include <Windows.h>

HINSTANCE g_hInst;

// 封装计数器更新逻辑，简化代码
void UpdateCounter(HWND hEdit, int value) {
    wchar_t buf[40] = {0};
    wsprintf(buf, L"%d", value);
    SetWindowText(hEdit, buf);
}

LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
    static int n = 0;
    static HWND hEdit;
    static HWND hButton;
    static UINT_PTR timerId = 0;
    static bool isButtonPressed = false;

    switch (uMsg) {
    case WM_CREATE:
        hEdit = CreateWindow(L"EDIT", L"0", WS_CHILD | WS_VISIBLE | ES_CENTER | ES_READONLY, 100, 100, 100, 20, hWnd, (HMENU)1, g_hInst, NULL);
        // 添加BS_NOTIFY样式，启用按钮状态通知
        hButton = CreateWindow(L"BUTTON", L"▴", WS_CHILD | WS_VISIBLE | BS_LEFT | BS_NOTIFY, 204, 100, 20, 20, hWnd, (HMENU)2, g_hInst, NULL);
        break;
    case WM_COMMAND: {
        HWND ctlHwnd = (HWND)lParam;
        int ctlId = LOWORD(wParam);
        int notificationCode = HIWORD(wParam);

        if (ctlId == 2) { // 目标按钮ID
            if (notificationCode == BN_CLICKED || notificationCode == BN_PUSHED) {
                if (!isButtonPressed) {
                    isButtonPressed = true;
                    n++;
                    UpdateCounter(hEdit, n);
                    // 设置定时器，间隔100ms（可根据需求调整速度）
                    timerId = SetTimer(hWnd, 1, 100, NULL);
                }
            } else if (notificationCode == BN_UNPUSHED) {
                isButtonPressed = false;
                if (timerId != 0) {
                    KillTimer(hWnd, timerId);
                    timerId = 0;
                }
            }
        }
        break;
    }
    case WM_TIMER: {
        // 按钮保持按下状态时，持续递增计数器
        if (isButtonPressed) {
            n++;
            UpdateCounter(hEdit, n);
        }
        break;
    }
    case WM_DESTROY:
        // 程序退出前销毁定时器
        if (timerId != 0) {
            KillTimer(hWnd, timerId);
        }
        PostQuitMessage(EXIT_SUCCESS);
        break;
    default:
        return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    return 0;
}

int WINAPI WinMain(
    HINSTANCE hInst,
    HINSTANCE hPrevInst,
    LPSTR lpCmdLine,
    int iCmdShow)
{
    g_hInst = hInst;

    WNDCLASS wndClass = {
        .style = CS_HREDRAW | CS_VREDRAW,
        .lpfnWndProc = WindowProc,
        .hInstance = hInst,
        .hIcon = LoadIcon(NULL, IDI_APPLICATION),
        .hCursor = LoadCursor(NULL, IDC_ARROW),
        .hbrBackground = (HBRUSH)GetStockObject(LTGRAY_BRUSH),
        .lpszMenuName = NULL,
        .lpszClassName = L"app",
    };
    if (!RegisterClass(&wndClass)) {
        OutputDebugString(L"Failed to register window class\n");
        return EXIT_FAILURE;
    }
    if (!CreateWindow(
        L"app",
        L"Counter",
        WS_OVERLAPPEDWINDOW | WS_VISIBLE,
        0, 0,
        1280, 720,
        NULL, NULL,
        hInst, NULL))
    {
        OutputDebugString(L"Failed to create window\n");
        return EXIT_FAILURE;
    }
    MSG msg = {};
    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (int)msg.wParam;
}

说明 #

• BS_NOTIFY样式是实现状态检测的核心，没有它按钮不会发送按下/松开的通知。
• 定时器间隔（100ms）可自行调整，数值越小，长按递增速度越快。
• 按下按钮时立即触发一次递增，之后定时器持续触发，直到按钮松开停止。

内容的提问来源于stack exchange，提问作者machine_1