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WM_CTLCOLOR消息 .

在每个控件开始绘制之前，都会向其父窗口发送WM_CTLCOLOR通告消息，在该消息的处理函数中，可以设置控件显示文本的前景色、背景色以及字体。该消息处理函数还要求返回一个画刷的句柄，用于在控件具体的绘制之前擦除其客户区。

WM_CTLCOLOR映射消息处理函数为afx_msg HBRUSH OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)。
常用代码为：

pDC->SetTextColor(RGB(255, 0, 0)); //设置文本前景色
pDC->SetBkColor(RGB(255, 255, 255)); //设置文本背景色
pDC->SetBkMode(TRANSPARENT); //TRANSPARENT或OPAQUE
pDC->SelectObject(...)

pDC->SetTextColor(RGB(255, 0, 0));    //设置文本前景色
pDC->SetBkColor(RGB(255, 255, 255));  //设置文本背景色
pDC->SetBkMode(TRANSPARENT);          //TRANSPARENT或OPAQUE
pDC->SelectObject(...)

简单示例如下：

[cpp] view plain copy print ?

//
//m_font1与m_font2为CTestDlg的成员，类型为CFont
//
BOOL CTestDlg::OnInitDialog()
{
......
// TODO: Add extra initialization here
m_font1.CreatePointFont(120, TEXT("Impact"));
m_font2.CreatePointFont(120, TEXT("Arial"));
......
}
HBRUSH CTestDlg::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);
// TODO: Change any attributes of the DC here
if (nCtlColor == CTLCOLOR_STATIC)
{
switch (pWnd->GetDlgCtrlID())
{
case IDC_STATIC_1:
pDC->SetTextColor(RGB(255, 0, 0));
pDC->SetBkColor(RGB(255, 255, 255));
pDC->SetBkMode(TRANSPARENT);
pDC->SelectObject(&m_font1);
return (HBRUSH)::GetStockObject(BLACK_BRUSH);
break;
case IDC_STATIC_2:
pDC->SetTextColor(RGB(255, 255, 0));
pDC->SetBkColor(RGB(255, 255, 255));
pDC->SelectObject(&m_font2);
return (HBRUSH)::GetStockObject(BLACK_BRUSH);
break;
default:
break;
}
}
// TODO: Return a different brush if the default is not desired
return hbr;
}

//
//m_font1与m_font2为CTestDlg的成员，类型为CFont
//
BOOL CTestDlg::OnInitDialog()
{
        ......
	// TODO: Add extra initialization here
        m_font1.CreatePointFont(120,  TEXT("Impact")); 
        m_font2.CreatePointFont(120,  TEXT("Arial"));
        ......
}

HBRUSH CTestDlg::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
	HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);

	// TODO:  Change any attributes of the DC here
	if (nCtlColor == CTLCOLOR_STATIC)
	{
		switch (pWnd->GetDlgCtrlID())
		{
		case IDC_STATIC_1:
			pDC->SetTextColor(RGB(255, 0, 0));
			pDC->SetBkColor(RGB(255, 255, 255));
			pDC->SetBkMode(TRANSPARENT);
			pDC->SelectObject(&m_font1);
			return (HBRUSH)::GetStockObject(BLACK_BRUSH);
			break;
		case IDC_STATIC_2:
			pDC->SetTextColor(RGB(255, 255, 0));
			pDC->SetBkColor(RGB(255, 255, 255));
			pDC->SelectObject(&m_font2);
			return (HBRUSH)::GetStockObject(BLACK_BRUSH);
			break;
		default:
			break;
		}
	}

	// TODO:  Return a different brush if the default is not desired
	return hbr;
}

说明一

OnCtlColor中的nCtlColor可为：
    CTLCOLOR_BTN       Button control
    CTLCOLOR_DLG       Dialog box
    CTLCOLOR_EDIT      Edit control
    CTLCOLOR_LISTBOX    List-box control
    CTLCOLOR_MSGBOX     Message box
    CTLCOLOR_SCROLLBAR  Scroll-bar control
    CTLCOLOR_STATIC     Static control

可见，WM_CTLCOLOR可作用于按钮控件CButton、编辑框控件CEdit、ListBox控件、Static控件、滚动条控件，也可作用于对话框本身。
注意：前面讲WM_CTLCOLOR为通告消息，也即是子控件发送给父窗口的，但对于对话框本身，它能收到nCtlColor为CTLCOLOR_DLG的WM_CTLCOLOR消息，这是自身发给自身的，显然，这时不是通告消息。

示例：

[cpp] view plain copy print ?

HBRUSH CTestDlg::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);
// TODO: Change any attributes of the DC here
if (nCtlColor == CTLCOLOR_DLG)
return (HBRUSH)::GetStockObject(BLACK_BRUSH);
else
pDC->SetTextColor(RGB(255, 0, 0));
// TODO: Return a different brush if the default is not desired
return hbr;
}

HBRUSH CTestDlg::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
	HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);

	// TODO:  Change any attributes of the DC here
	if (nCtlColor == CTLCOLOR_DLG)
		return (HBRUSH)::GetStockObject(BLACK_BRUSH);
	else
		pDC->SetTextColor(RGB(255, 0, 0));

	// TODO:  Return a different brush if the default is not desired
	return hbr;
}

    说明二

    OnCtlColor消息里面的处理对PushButton是不起作用的，由说明一中的示例效果也可以看出，而对CheckBox和RadioButton是OK的。附上CSDN给出的解释：
    Buttons with the BS_PUSHBUTTON, BS_DEFPUSHBUTTON, or BS_PUSHLIKE styles do not use the returned brush. Buttons with these styles are always drawn with the default system colors. Drawing push buttons requires several different brushes-face, highlight, and shadow-but the WM_CTLCOLORBTN message allows only one brush to be returned. To provide a custom appearance for push buttons, use an owner-drawn button.
    所以，对PushButton只能将其设置为owner-drawn button，然后响应控件通告消息WM_DRAWITEM来处理，该消息的响应函数原型为afx_msg void OnDrawItem(int nIDCtl, LPDRAWITEMSTRUCT lpDrawItemStruct)。

    
    说明三：对ComboBox控件的应用

ComboBox控件包含一个EditBox，当单击展开的时候，会出现一个ListBox列出所有的项目，注意，这时ListBox控件的父窗口不是这个ComboBox，而是ComboBox的父窗口。
    所以，如果要在代码中设置某个ComboBox所显示文字的字体颜色为红色(EditBox以及下拉ListBox中的文字)，假设该ComboBox的ID为IDC_COMBO，则使用如下代码将无任何作用。

[cpp] view plain copy print ?

if (pWnd->GetDlgCtrlID() == IDC_COMBO)
{
pDC->SetTextColor(RGB(255, 0, 0));
}

if (pWnd->GetDlgCtrlID() == IDC_COMBO)
{
    pDC->SetTextColor(RGB(255, 0, 0));
}

EditBox以及下拉ListBox中的文字颜色均没有改变。

    以下对话框中有两个ComboBox控件m_combo1，m_combo2。现要使m_combo1中显示的文字颜色为红色，而m_combo2为默认。代码如下

[cpp] view plain copy print ?

HBRUSH CTestDlg::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);
// TODO: Change any attributes of the DC here
//对m_combo1的EditBox(该EditBox的父窗口为m_combo1)
if (nCtlColor == CTLCOLOR_EDIT
&& pWnd->GetParent()->GetDlgCtrlID() == m_combo1.GetDlgCtrlID())
{
pDC->SetTextColor(RGB(255, 0, 0));
}
//对m_combo1下拉的ListBox
if (nCtlColor == CTLCOLOR_LISTBOX
&& m_combo1.GetParent()->GetDlgCtrlID() == pWnd->GetParent()->GetDlgCtrlID())
{
//获取ListBox和m_combo1的屏幕坐标范围
RECT rectListBox;
RECT rectComboBox;
pWnd->GetWindowRect(&rectListBox);
m_combo1.GetWindowRect(&rectComboBox);
//如果该ListBox刚好在m_combo1的下面，则是单击m_combo1产生的下拉ListBox
if (rectListBox.left == rectComboBox.left
&& rectListBox.top == rectComboBox.bottom)
{
pDC->SetTextColor(RGB(255, 0, 0));
}
}
// TODO: Return a different brush if the default is not desired
return hbr;
}

HBRUSH CTestDlg::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
	HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);

	// TODO:  Change any attributes of the DC here

	//对m_combo1的EditBox(该EditBox的父窗口为m_combo1)
	if (nCtlColor == CTLCOLOR_EDIT
		&& pWnd->GetParent()->GetDlgCtrlID() == m_combo1.GetDlgCtrlID())
	{
		pDC->SetTextColor(RGB(255, 0, 0));
	}

	//对m_combo1下拉的ListBox
	if (nCtlColor == CTLCOLOR_LISTBOX
		&& m_combo1.GetParent()->GetDlgCtrlID() == pWnd->GetParent()->GetDlgCtrlID())
	{
		//获取ListBox和m_combo1的屏幕坐标范围
		RECT rectListBox;
		RECT rectComboBox;
		pWnd->GetWindowRect(&rectListBox);
		m_combo1.GetWindowRect(&rectComboBox);
		//如果该ListBox刚好在m_combo1的下面，则是单击m_combo1产生的下拉ListBox
		if (rectListBox.left == rectComboBox.left
			&& rectListBox.top == rectComboBox.bottom)
		{
			pDC->SetTextColor(RGB(255, 0, 0));
		}
	}

	// TODO:  Return a different brush if the default is not desired
	return hbr;
}

效果如下：

更简单的办法是：利用向导新增MFC类CMyComboBox : CComboBox，再增加WM_CTLCOLOR消息的响应函数。（注意：ComboBox下的EditBox和ListBox均会向ComboBox窗口发送WM_CTLCOLOR消息，如果在ComboBox对应的消息映射表没有找到对应的处理函数，再向CComboBox的父窗口发送WM_CTLCOLOR消息，具体可参考文章WM_NOTIFY消息流程实例分析）

[cpp] view plain copy print ?

BEGIN_MESSAGE_MAP(CMyComboBox, CComboBox)
ON_WM_CTLCOLOR()
END_MESSAGE_MAP()
HBRUSH CMyComboBox::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
HBRUSH hbr = CComboBox::OnCtlColor(pDC, pWnd, nCtlColor);
// TODO: Change any attributes of the DC here
pDC->SetTextColor(RGB(255, 255, 0));
// TODO: Return a different brush if the default is not desired
return hbr;
}

BEGIN_MESSAGE_MAP(CMyComboBox, CComboBox)
	ON_WM_CTLCOLOR()
END_MESSAGE_MAP()

HBRUSH CMyComboBox::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
	HBRUSH hbr = CComboBox::OnCtlColor(pDC, pWnd, nCtlColor);

	// TODO:  Change any attributes of the DC here
	pDC->SetTextColor(RGB(255, 255, 0));

	// TODO:  Return a different brush if the default is not desired
	return hbr;
}

pDC->SetTextColor(RGB(255, 255, 0));一句代码就可以实现上面的功能。

    说明四、WM_CTLCOLOR为通告消息，所以也可以在反射消息中处理。
ON_WM_CTLCOLOR_REFLECT()


from：http://blog.csdn.net/wangyao1052/article/details/8070393

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原文地址：https://www.cnblogs.com/lidabo/p/2804246.html