为什么在触发 WM_COMMAND 时 WM_KEYDOWN 不起作用？

Question

当我单击客户端窗口中的按钮然后按下向下箭头键时，WM_KEYDOWN 不会发送到我的 Windows 程序，但其他情况始终有效，因此要解决此问题，我必须单击外部我的客户端窗口，然后单击我的客户端窗口（但不是按钮）然后 WM_KEYDOWN 将起作用，有没有更好的方法来停止我的按钮的焦点？

代码如下：

#include <iostream>
#define _WIN32_WINNT 0x0501
#include <Windows.h>
#include <winuser.h>
#include <vector>
#include<string>
using namespace std;

const char* className = "MyCLASSNAME!";

HWND hButton;
RECT rect;
POINT p = {0, 0};

LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{


    switch(msg)
    {
    case WM_CREATE:

        hButton = CreateWindow(TEXT("BUTTON"), TEXT("1"), WS_VISIBLE | WS_CHILD, 8, 41, 50, 50, hWnd, (HMENU)1, NULL, NULL);
        break;

    case WM_KEYDOWN:

        switch (wParam)
        {

        case VK_DOWN:

            if(GetWindowRect(hButton, &rect))
            {
                POINT p1 = {rect.left, rect.top};
                ScreenToClient(hWnd, &p1);
                SetWindowPos(hButton, NULL, p1.x, p1.y, rect.right - rect.left + 1, rect.bottom - rect.top + 1, SWP_SHOWWINDOW);

            }

            break;
        }

        break;
    case WM_LBUTTONDOWN:
        GetCursorPos( &p );


        GetClientRect(hButton, &rect);
        SetWindowPos(hButton, NULL, p.x, p.y - 22, rect.right, rect.bottom, SWP_SHOWWINDOW);
        break;
    case WM_COMMAND:


        switch(LOWORD(wParam))
        {
        case 1:
            break;
        }

        break;

    case WM_CLOSE:
        DestroyWindow(hWnd);
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;

    default:
        return DefWindowProc(hWnd, msg, wParam, lParam);
    }

    return 0;
}

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{

    WNDCLASSEXA wc;
    HWND hWnd;
    MSG msg;

    wc.cbClsExtra = 0;
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.cbWndExtra = 0;
    wc.hbrBackground = CreateSolidBrush(RGB(0,0,0));
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
    wc.hInstance = hInstance;
    wc.lpfnWndProc = WndProc;
    wc.lpszClassName = className;
    wc.lpszMenuName = "MENU!";
    wc.style = NULL;

    RegisterClassEx(&wc);

    hWnd = CreateWindowEx(WS_EX_LAYERED, className, "hello", WS_OVERLAPPEDWINDOW, 0, 0, 500, 500, NULL, NULL, hInstance, NULL);
    SetLayeredWindowAttributes(hWnd, 0, 255, LWA_ALPHA);

    ShowWindow(hWnd, nShowCmd);
    UpdateWindow(hWnd);

    while(GetMessage(&msg, hWnd, 0, 0) > 0)
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);


    }


    return msg.wParam;
}

Answer 1

原因是当您按下按钮时，您会关注当前按钮，因此您的WM_KEYDOWN 消息会发送到该按钮。

所以需要对按钮进行子类化，并处理按钮的WM_KEYDOWN消息。可以参考document。

这是修改后的示例：

#include <iostream>
#define _WIN32_WINNT 0x0501
#include <Windows.h>
#include <winuser.h>
#include <vector>
#include <string>
#include <CommCtrl.h>
using namespace std;

const char* className = "MyCLASSNAME!";
HWND hWnd;
HWND hButton;
RECT rect;
POINT p = { 0, 0 };
WNDPROC ButtonOldProc;

LRESULT CALLBACK ButtonProcNew(HWND hwnd, UINT message, WPARAM wParam,LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    switch (message)
    {
    case WM_KEYDOWN:
        switch (wParam)
        {
        case VK_DOWN:

            if (GetWindowRect(hButton, &rect))
            {
                POINT p1 = { rect.left, rect.top };
                ScreenToClient(hWnd, &p1);
                SetWindowPos(hButton, NULL, p1.x, p1.y, rect.right - rect.left + 1, rect.bottom - rect.top + 1, SWP_SHOWWINDOW);
            }
            break;
        }
        break;
    default:
        return DefSubclassProc(hwnd, message, wParam, lParam);
    }
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg)
    {
    case WM_CREATE:

        hButton = CreateWindow(TEXT("BUTTON"), TEXT("1"), WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON, 8, 41, 50, 50, hWnd, (HMENU)1, NULL, NULL);
        SetWindowSubclass(hButton, ButtonProcNew, 0, 0);
        break;

    case WM_KEYDOWN:
        switch (wParam)
        {
        case VK_DOWN:

            if (GetWindowRect(hButton, &rect))
            {
                POINT p1 = { rect.left, rect.top };
                ScreenToClient(hWnd, &p1);
                SetWindowPos(hButton, NULL, p1.x, p1.y, rect.right - rect.left + 1, rect.bottom - rect.top + 1, SWP_SHOWWINDOW);
            }
            break;
        }

        break;
    case WM_LBUTTONDOWN:
        GetCursorPos(&p);
        GetClientRect(hButton, &rect);
        SetWindowPos(hButton, NULL, p.x, p.y - 22, rect.right, rect.bottom, SWP_SHOWWINDOW);
        break;
    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case 1:
            break;
        }
        break;
    case WM_CLOSE:
        DestroyWindow(hWnd);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, msg, wParam, lParam);
    }

    return 0;
}

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{

    WNDCLASSEXA wc;
    MSG msg;
    wc.cbClsExtra = 0;
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.cbWndExtra = 0;
    wc.hbrBackground = CreateSolidBrush(RGB(0, 0, 0));
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
    wc.hInstance = hInstance;
    wc.lpfnWndProc = WndProc;
    wc.lpszClassName = className;
    wc.lpszMenuName = "MENU!";
    wc.style = NULL;
    RegisterClassEx(&wc);
    hWnd = CreateWindowEx(WS_EX_LAYERED, className, "hello", WS_OVERLAPPEDWINDOW, 0, 0, 500, 500, NULL, NULL, hInstance, NULL);
    SetLayeredWindowAttributes(hWnd, 0, 255, LWA_ALPHA);
    ShowWindow(hWnd, nShowCmd);
    UpdateWindow(hWnd);

    while (GetMessage(&msg, hWnd, 0, 0) > 0)
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

注意：需要链接 Comctl32.lib

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