WM_command catch按钮在c ++ win32中按下

Question

我正在尝试使用c ++ win32获取按钮按下事件 WM_Command

HWND hBtn;
HWND  hBtnParent = HWND("UploadVideo");
HWND SelectVideoBTN, UploadBTN;
HWND hWnd;

HINSTANCE hUpload;
WNDCLASSEX wcexUpload;
int nCmdShowUpload = 1;
using namespace std;

LRESULT CALLBACK WindowProcedure(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    loader::alert("rrr");
    switch (message)
    {
    case WM_COMMAND:
        if (LOWORD(wParam) == WORD(SelectVideoBTN)) {
            loader::alert("hello");
        }
        break;
    default:
        return DefWindowProc(hwnd, message, wParam, lParam);
    }
    return 0;
}

SelectVideoBTN = CreateWindow(
            L"BUTTON",  // Predefined class; Unicode assumed 
            L"Select Video's",      // Button text 
            WS_TABSTOP | WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON,  // Styles 
            10,         // x position 
            460,         // y position 
            100,        // Button width
            25,        // Button height
            hWnd,     // Parent window
            NULL,       // No menu.
            (HINSTANCE)GetWindowLong(hWnd, GWL_HINSTANCE),
            NULL);      // Pointer not needed.

        UploadBTN = CreateWindow(
            L"BUTTON",  // Predefined class; Unicode assumed 
            L"Upload",      // Button text 
            WS_TABSTOP | WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON,  // Styles 
            390,         // x position 
            460,         // y position 
            100,        // Button width
            25,        // Button height
            hWnd,     // Parent window
            NULL,       // No menu.
            (HINSTANCE)GetWindowLong(hWnd, GWL_HINSTANCE),
            NULL);      // Pointer not needed.

我一直在看这个例子 - http://forums.devshed.com/programming-42/create-button-clicked-148407.html - 但我不能让它工作,它甚至不会打电话的CALLBACK WindowProcedure-有没有人谁可以帮我？

按钮出现在window我创建的,我通过创建window-

WNDCLASSEX vidUploader;

    vidUploader.cbSize = sizeof(WNDCLASSEX);

    vidUploader.style = CS_HREDRAW | CS_VREDRAW;
    vidUploader.lpfnWndProc = WndProc;
    vidUploader.cbClsExtra = 0;
    vidUploader.cbWndExtra = 0;
    vidUploader.hInstance = hUpload;
    vidUploader.hIcon = LoadIcon(hUpload, MAKEINTRESOURCE(IDI_P2GOVIDEOUPLOADER20));
    vidUploader.hCursor = LoadCursor(NULL, IDC_ARROW);
    vidUploader.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    vidUploader.lpszMenuName = MAKEINTRESOURCE(IDC_P2GOVIDEOUPLOADER20);
    vidUploader.lpszClassName = (LPCWSTR)(L"UploadVideo");
    vidUploader.hIconSm = LoadIcon(wcexUpload.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    RegisterClassEx(&vidUploader);

    hInst = hUpload; // Store instance handle in our global variable

然后创建窗口

    hWnd = CreateWindow((LPCWSTR)(L"UploadVideo"), (LPCWSTR)(L"Upload Video's"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 500, 100, NULL, NULL, hUpload, NULL);
if (!hWnd)
        {
            MessageBox(NULL, _T("Call to CreateWindow failed!"), _T("Win32 Guided Tour"), NULL);

            return 1;
        }


    // The parameters to ShowWindow explained:
    // hWnd: the value returned from CreateWindow
    // nCmdShow: the fourth parameter from WinMain
    ShowWindow(hWnd,
        nCmdShowUpload);

    UpdateWindow(hWnd);

Answer 1

子窗口(即具有WS_CHILD窗口样式的窗口)由唯一的数值标识,通常称为控件ID或窗口ID.WM_COMMAND例如,它在收到消息时传递给父节点.但是,您从未为按钮控件分配控件ID,并且父窗口无法识别它们.在子窗口的情况下,对CreateWindow的调用中的hMenu参数被重载以携带唯一标识符:

hMenu
对于子窗口,hMenu指定子窗口标识符,这是一个对话框控件用于通知其父级事件的整数值.应用程序确定子窗口标识符; 对于具有相同父窗口的所有子窗口,它必须是唯一的.

换句话说,您的应用程序选择一个数值来分配给控件.由于对话管理器已经使用较低的ID(例如IDOK),因此通常的做法是从100开始分配控制ID(请参阅为什么对话框编辑器开始为控制ID分配100？).

然后,在WM_COMMAND处理程序中,您可以LOWORD(wParam)与分配给按钮控件的标识符进行比较.

您需要对代码应用以下更改.

// Declare control IDs. This is usually done in a file called Resource.h
#define IDC_SELECT_VIDEO (100)

更改窗口创建代码:

SelectVideoBTN = CreateWindow(
            L"BUTTON",  // Predefined class; Unicode assumed 
            L"Select Video's",      // Button text 
            WS_TABSTOP | WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON,  // Styles 
            10,         // x position 
            460,        // y position 
            100,        // Button width
            25,         // Button height
            hWnd,       // Parent window
            (HMENU)IDC_SELECT_VIDEO, // Assign appropriate control ID
            (HINSTANCE)GetWindowLong(hWnd, GWL_HINSTANCE),
            NULL);      // Pointer not needed.

检查WM_COMMAND处理程序中的控件ID :

    switch (message)
    {
    case WM_COMMAND:
        if (LOWORD(wParam) == IDC_SELECT_VIDEO) {
            loader::alert("hello");
        }
        break;
    default:
        return DefWindowProc(hwnd, message, wParam, lParam);
    }

如果根本没有调用您的窗口过程,这可能意味着您没有在调用线程上调度消息.GUI线程始终需要消息循环.标准消息循环足够:

MSG msg = {0};
while (GetMessage(&msg, NULL, 0, 0))
{
    TranslateMessage(&msg);
    DispatchMessage(&msg);
}