优化校准背景为灰色，我希望它为白色 [英] Picture Control background is gray and I want it white

问题描述

我的应用程序有一个图片控件，其背景是灰色，我希望它是白色.我已经尝试了几件事，例如:派生一个类并覆盖OnPaint方法；响应WM_CTLCOLOR消息(添加ON_WM_CTLCOLOR()并对其进行处理)，但没有成功.

My application has a picture control, whose background is gray and I want it to be white. I already tried several things, like: derive a class and override OnPaint method; respond to WM_CTLCOLOR message (adding ON_WM_CTLCOLOR()and processing it), but no success.

邮件地图上的条目:

ON_WM_CTLCOLOR()

实施:

BOOL CMyDialog::OnInitDialog()
{
    __super::OnInitDialog();

    white.CreateSolidBrush(RGB(255,255,255));

    //...

    return TRUE;  // return TRUE  unless you set the focus to a control
}


HBRUSH CMyDialog::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
    if (pWnd == GetDlgItem(IDC_PICTURE))
    {
        return white;
    }

    return __super::OnCtlColor(pDC, pWnd, nCtlColor);
}

头文件类定义:

CBrush white;

HBRUSH OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor);

推荐答案

在使用Spy ++进行一些调试之后，我意识到优化校准是静态控件，必须处理的消息不是WM_CTLCOLOR而是WM_CTLCOLORSTATIC

After some debugging using Spy++, I've realized the Picture Control is a Static Control and the message I have to process is not WM_CTLCOLOR but WM_CTLCOLORSTATIC

因此，在包含它的对话框中，我将消息映射从更改为

So, on the dialog that contains it I changed the message map from

ON_WM_CTLCOLOR()

到

ON_MESSAGE(WM_CTLCOLORSTATIC, OnCtlColorStatic)

---

在实现中，将方法从更改为

---

On the implementation, change the method from

HBRUSH CMyDialog::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
    if (pWnd == GetDlgItem(IDC_PICTURE))
    {
        return white;
    }

    return __super::OnCtlColor(pDC, pWnd, nCtlColor);
}

到

LRESULT CMyDialog::OnCtlColorStatic(WPARAM wParam, LPARAM lParam)
{
    HWND hWnd = (HWND)lParam;

    if (::GetDlgCtrlID(hWnd) == IDC_PICTURE)
        return (LRESULT)white.GetSafeHandle();

    return DefWindowProc(WM_CTLCOLORSTATIC, wParam, lParam);
}

---

然后在头文件中，也将方法从更改为

---

And in the header file, change also the method from

HBRUSH OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor);

到

LRESULT OnCtlColorStatic(WPARAM wParam, LPARAM lParam);

---

请注意一个细微的区别:旧的通过直接返回 HBRUSH 刷柄而起作用；新的期望一个函数返回一个 LRESULT 类型的变量，因此强制转换.

---

Notice a subtle difference: the old one worked by returning the HBRUSH brush handle directly; the new one expects a function returning a LRESULT typed variable, so the cast.

结果就是我所期望的:

UPDATE :最近，我需要做一件事，我必须设置静态"的文本颜色"，并且发现我也可以获取其设备上下文:

HDC hDC= (HDC)wParam;
HWND hWnd = (HWND)lParam;

因此，在我可以通过以下方式轻松完成此操作之后:

So, after I could easily do it by:

SetBkMode(hDC, TRANSPARENT);
SetTextColor(hDC, RGB(0,127,127));

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