【Win32】怎么通过调节滚动条来调节编辑框的背景颜色？

Question

想写一个win32的画图程序，用三个垂直滚动条来调节三个编辑框的背景颜色，来分别为Red，Green，Blue。然后在第四个编辑框里显示这三种颜色叠加的效果，来达到改变画笔颜色的效果。但运行后发现无论怎么拖动滚动条滑块，编辑框的颜色都不变，一直保持为黑色，不知道是怎么回事。附以下代码，求大佬们多多指教（手动鞠躬感谢）。
（ps. 本人菜鸟一只，如果代码其他地方也有疏漏，也请大佬们指正，感谢！！！）

case WM_CREATE:
{
    LPCREATESTRUCT pcs = (LPCREATESTRUCT)lParam;

    hScrollBar_S = CreateWindow(L"scrollbar", L"bar", WS_CHILDWINDOW | WS_VISIBLE | SBS_HORZ, 20, 20, 200, 20, hwnd, (HMENU)1001, pcs->hInstance, NULL);
    SendMessage(hScrollBar_S, SBM_SETRANGE, 0, 100);
    SendMessage(hScrollBar_S, SBM_SETPOS, 0, true);

    hEdit_R = CreateWindow(L"edit", L"", WS_CHILDWINDOW | WS_VISIBLE | ES_NOHIDESEL, 20, 50, 50, 50, hwnd, (HMENU)1002, pcs->hInstance, NULL);
    hEdit_G = CreateWindow(L"edit", L"", WS_CHILDWINDOW | WS_VISIBLE | ES_NOHIDESEL, 80, 50, 50, 50, hwnd, (HMENU)1003, pcs->hInstance, NULL);
    hEdit_B = CreateWindow(L"edit", L"", WS_CHILDWINDOW | WS_VISIBLE | ES_NOHIDESE , 140, 50, 50, 50, hwnd, (HMENU)1004, pcs->hInstance, NULL);
    hEdit_A = CreateWindow(L"edit", L"", WS_CHILDWINDOW | WS_VISIBLE | ES_NOHIDESEL，230, 50, 50, 50, hwnd, (HMENU)1005, pcs->hInstance, NULL);

    hScrollBar_R = CreateWindow(L"scrollbar", L"bar", WS_CHILDWINDOW | WS_VISIBLE | SBS_VERT, 35,110, 20, 200, hwnd, (HMENU)1006, pcs->hInstance, NULL);
    SendMessage(hScrollBar_R, SBM_SETRANGE, 0, 255);
    SendMessage(hScrollBar_R, SBM_SETPOS, 0, true);

    hScrollBar_G = CreateWindow(L"scrollbar", L"bar", WS_CHILDWINDOW | WS_VISIBLE | SBS_VERT, 95, 110, 20, 200, hwnd, (HMENU)1007, pcs->hInstance, NULL);
    SendMessage(hScrollBar_G, SBM_SETRANGE, 0, 255);
    SendMessage(hScrollBar_G, SBM_SETPOS, 0, true);

    hScrollBar_B = CreateWindow(L"scrollbar", L"bar", WS_CHILDWINDOW | WS_VISIBLE | SBS_VERT, 155, 110, 20, 200, hwnd, (HMENU)1008, pcs->hInstance, NULL);
    SendMessage(hScrollBar_B, SBM_SETRANGE, 0, 255);
    SendMessage(hScrollBar_B, SBM_SETPOS, 0, true);
}

case WM_HSCROLL:
{
    WORD code = LOWORD(wParam);
    HWND hCtrl = (HWND)lParam;
    int pos = SendMessage(hCtrl, SBM_GETPOS, 0, 0);
    switch (code)
    {
    case SB_LINELEFT:
        pos -= 1;
        break;
    case SB_LINERIGHT:
        pos += 1;
        break;
    case SB_PAGELEFT:
        pos -= 10;
        break;
    case SB_PAGERIGHT:
        pos += 10;
        break;
    case SB_THUMBPOSITION:
        pos = HIWORD(wParam);
        break;
    }
    SendMessage(hCtrl, SBM_SETPOS, pos, true);
}

case WM_VSCROLL:
{
    WORD code = LOWORD(wParam);
    HWND hCtrl = (HWND)lParam;
    int pos = SendMessage(hCtrl, SBM_GETPOS, 0, 0);
    switch (code)
    {
    case SB_LINEUP:
        pos -= 1;
        break;
    case SB_LINEDOWN:
        pos += 1;
        break;
    case SB_PAGEUP:
        pos -= 10;
        break;
    case SB_PAGEDOWN:
        pos += 10;
        break;
    case SB_THUMBPOSITION:
        pos = HIWORD(wParam);
        break;
    }
    SendMessage(hCtrl, SBM_SETPOS, pos, true);
}

case WM_CTLCOLOREDIT:
{
    HDC hdc = (HDC)wParam;
    HWND hEdit = (HWND)lParam;
    UINT CtrlID = GetWindowLong(hEdit, GWL_ID);
    HWND hCtrl = (HWND)lParam;
    if (CtrlID == 1002)
    {
        int pos_R = GetScrollPos(hScrollBar_R, SB_VERT);
        SetBkMode(hdc, TRANSPARENT);
        return (LRESULT)CreateSolidBrush(RGB(pos_R, 0, 0));
    }
    else if (CtrlID == 1003)
    {
        int pos_G = GetScrollPos(hScrollBar_G, SB_VERT);
        SetBkMode(hdc, TRANSPARENT);
        return (LRESULT)CreateSolidBrush(RGB(0, pos_G, 0));
    }
    else if (CtrlID == 1004)
    {
        int pos_B = GetScrollPos(hScrollBar_B, SB_VERT);
        SetBkMode(hdc, TRANSPARENT);
        return (LRESULT)CreateSolidBrush(RGB(0, 0, pos_B));
    }
    else
    {
        int pos_R = GetScrollPos(hScrollBar_R, SB_VERT);
        int pos_G = GetScrollPos(hScrollBar_G, SB_VERT);
        int pos_B = GetScrollPos(hScrollBar_B, SB_VERT);
        SetBkMode(hdc, TRANSPARENT);
        return (LRESULT)CreateSolidBrush(RGB(pos_R, pos_G, pos_B));
    }
}break;

}

Answer 1

不知道你这个问题是否已经解决, 如果还没有解决的话:

• 建议你看下这篇博客👉 ：Win32汇编备份--循环结构

如果你已经解决了该问题, 非常希望你能够分享一下解决方案, 以帮助更多的人 ^-^