子类化按钮在每次重复单击时都不产生动画

时间:2018-09-08 17:21:04

标签: c++ user-interface winapi button subclass

我在WM_CREATE回调的WindowProc消息中创建了一个自定义子类按钮。这是创建和子类说明,以及用于控制按钮状态的结构:

static button_state btnstateBtnInstall;
hBtnInstall = CreateWindow(WC_BUTTON, L"Button", WS_CHILD | WS_VISIBLE, (window_width / 2) - (btn_install_width / 2), window_height - (window_height / 6) - (btn_install_height / 2), btn_install_width, btn_install_height, hwnd, (HMENU)HMENU_btn_install, NULL, NULL);
SetWindowSubclass(hBtnInstall, BtnInstallProc, 0, (DWORD_PTR)&btnstateBtnInstall);

结构定义如下:

struct button_state
{
    bool pushed;
    button_state() { pushed = false; }
};

子类过程的编码如下:

LRESULT CALLBACK BtnInstallProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubClass, DWORD_PTR dwRefData)
{
    button_state* state = (button_state*)dwRefData;

    // Omitted part where I create brushes and font to be used for painting

    switch (msg)
    {
    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hwnd, &ps);
        RECT rc = ps.rcPaint;

        POINT pt;
        GetCursorPos(&pt);
        ScreenToClient(hwnd, &pt);
        BOOL hover = PtInRect(&rc, pt);

        if (state->pushed)
        {
            // Pushed
            FillRect(hdc, &rc, hBrPushed);
        }
        else if (hover)
        {
            // Mouse over
            FillRect(hdc, &rc, hBrHover);
        }
        else
        {
            // Normal
            FillRect(hdc, &rc, hBrNormal);
        }

        SetBkMode(hdc, TRANSPARENT);
        SetTextColor(hdc, RGB(255, 255, 255));
        SelectFont(hdc, SegoeUI);
        static LPCWSTR InstallBtnTxt = L"Install";
        static int InstallBtnTxtLen = static_cast<int>(wcslen(InstallBtnTxt));  // Should be a safe cast, for small arrays like this one
        DrawText(hdc, InstallBtnTxt, InstallBtnTxtLen, &rc, DT_SINGLELINE | DT_CENTER | DT_VCENTER);

        EndPaint(hwnd, &ps);
        return 0;
    }

    case WM_LBUTTONDOWN:
    {
        state->pushed = true;

        break;
    }

    case WM_LBUTTONUP:
    {
        state->pushed = false;

        break;
    }

    // Omitted part where I handle WM_DESTROY to do cleanup

    }

    return DefSubclassProc(hwnd, msg, wParam, lParam);
}

为了将我的按钮的行为与标准按钮的行为进行比较,我创建了另一个没有子类并且仅使用标准BUTTON类和WS_VISIBLE | WS_CHILD属性的按钮。

从随附的gif文件中可以看到,当我反复单击标准班级按钮时,每次单击都会产生动画,而当我多次点击我创建的按钮时使用此代码,似乎并没有捕获到每次点击,但(如您所见)却捕获了其中的50%

我想念什么?为什么我的按钮不能像标准类中的按钮那样反应灵敏?

TL; DR :在我的子类按钮上缓慢单击时,绘画是正确的。从我的图像中可以看到,重复单击时,我的按钮和标准按钮之间的差异很大。如何使我的控件像标准控件一样灵敏?

enter image description here

1 个答案:

答案 0 :(得分:4)

快速单击时,某些WM_LBUTTONDOWN消息将被WM_LBUTTONDBLCLK替代(默认双击处理)。您需要像处理WM_LBUTTONDOWN消息一样处理它。

case WM_LBUTTONDOWN:
case WM_LBUTTONDBLCLK: // <-- Added
{
    state->pushed = true;

    break;
}