c++ - 使用 WINAPI 如何更改复选框按钮的值？

Question

目前我在 WM_CREATE 中创建了一个复选框:

hwndButtonPollFlag = 
CreateWindow(
    TEXT("BUTTON"), 
    TEXT(sA.getMonitor(monitorSelected)->szDevice),
    WS_CHILD | WS_VISIBLE | SS_WHITERECT | BS_CHECKBOX, 
    0, 
    0, 
    0,
    0, 
    hwnd, 
    (HMENU)IDB_PollFlag, 
    hInstance, 
    NULL);

每当单击另一个按钮时，我试图更改它的值:

    if (sA.getScreenArray(monitorSelected)->getPollFlag())
    {
        SetWindowLongPtr(hwndButtonPollFlag, GCL_STYLE, WS_VISIBLE | BST_CHECKED);
    }
    else
    {
        SetWindowLongPtr(hwndButtonPollFlag, GCL_STYLE, WS_VISIBLE | BST_UNCHECKED);
    }
    SetWindowText(hwndButtonPollFlag, TEXT(sA.getMonitor(monitorSelected)->szDevice));

这确实会更改显示在复选框旁边的文本，但不会更改按钮的实际状态。此外，我希望复选框只有两种状态(选中或未选中)，除了按钮返回之外，是否还有其他方法可以创建该效果:

switch (HIWORD(wParam))
    {
    case BST_CHECKED:
        sA.getScreenArray(monitorSelected)->setPollFlag(true);
        return 0;
    case BST_INDETERMINATE:
        if (sA.getScreenArray(monitorSelected)->getPollFlag())
        {
            SetWindowLongPtr(hwndButtonPollFlag, GCL_STYLE, WS_VISIBLE | BST_UNCHECKED);
        }
        else
        {
            SetWindowLongPtr(hwndButtonPollFlag, GCL_STYLE, WS_VISIBLE | BST_CHECKED);
        }
        return 0;
    case BST_UNCHECKED:
        sA.getScreenArray(monitorSelected)->setPollFlag(false);
        return 0;
    }

编辑:正如 Mark Ransom 所说，我使用带有 BM_GETCHECK 和 BM_SETCHECK 标志的消息:

    case IDB_MONITOR:
    monitorSelected = LOWORD(lParam);
    if (sA.getScreenArray(monitorSelected)->getPollFlag())
    {
        SendMessage(hwndButtonPollFlag, BM_SETCHECK, BST_CHECKED, NULL);
    }
    else
    {
        SendMessage(hwndButtonPollFlag, BM_SETCHECK, BST_UNCHECKED, NULL);
    }
    SetWindowText(hwndButtonPollFlag, TEXT(sA.getMonitor(monitorSelected)->szDevice));
    return 0;
case WM_COMMAND:
    //sA.getScreenArray(monitorSelected)->setPollFlag(LOWORD(lParam));
    switch (LOWORD(wParam))
    {
    case IDB_PollFlag:
        if (SendMessage(GetDlgItem(hwnd, IDB_PollFlag), BM_GETCHECK, 0, 0) == BST_CHECKED)
        {
            SendMessage(hwndButtonPollFlag, BM_SETCHECK, BST_CHECKED, NULL);
            sA.getScreenArray(monitorSelected)->setPollFlag(true);
        }
        else {
            SendMessage(hwndButtonPollFlag, BM_SETCHECK, BST_UNCHECKED, NULL);
            sA.getScreenArray(monitorSelected)->setPollFlag(false);
        }
        break;
    }
    return 0;

Answer 1

您需要发送 BM_SETCHECK消息。

SendMessage(hwndButtonPollFlag, BM_SETCHECK, BST_CHECKED, 0);