Button按钮控件自绘操作

1、首先为工程CButton类的派生类CMyButton,在CMyButton的头文件中添加一个用于保存图标的成员变量和一个设置函数：用来为按钮加载我们导入的图标。

public:
	HICON m_hIcon;
	void SetIcon(UINT nIcon)
	{
		m_hIcon = AfxGetApp()->LoadIcon(nIcon);
	}

	//......

2、在CMyButton.cpp中重写虚函数：virtual void DrawItem(LPDRAWITEMSTRUCT lpDIS);

void CMyButton::DrawItem(LPDRAWITEMSTRUCT lpDIS)
{
	CDC *dc;
	//将句柄转换为CDC类的对象,以下两种方法都可以
	dc = CDC::FromHandle(lpDIS->hDC);
	//dc.Attach(lpDIS->hDC);

	//获取按钮的矩形区域
	CRect RtBtn = lpDIS->rcItem;

	dc->FillSolidRect(RtBtn,RGB(100,50,100));

	//如果按钮的状态为选中，矩形框向右下方移动
	if (lpDIS->itemState & ODS_SELECTED)
	{
		RtBtn.OffsetRect(1,1);
	}

	//画出自定义图标到按钮上
	CRect RtIcon = RtBtn;

	RtIcon.top = (RtIcon.Height()-16)/2;

	RtIcon.left = RtIcon.left + 5;

	dc->SetBkMode(TRANSPARENT);

	DrawIconEx(lpDIS->hDC,RtIcon.left,RtIcon.top,m_hIcon,16,16,0,NULL,DI_NORMAL);
	//dc.DrawIcon(RtIcon.left,RtIcon.top,m_hIcon);

	CRect RtText;
	RtText.CopyRect(RtBtn);

	CString strText;
	GetWindowText(strText);

	//向右平移文字
	RtText.left += 20;

	dc->SetTextColor(GetSysColor(COLOR_WINDOWTEXT));

	dc->DrawText(strText,RtText,DT_CENTER|DT_VCENTER|DT_SINGLELINE);

	//画按钮的边框
	if (lpDIS->itemState & ODS_SELECTED)
	{
		dc->DrawEdge(&RtBtn,BDR_SUNKENINNER,BF_RECT);
	}else{
		dc->DrawEdge(&RtBtn,BDR_RAISEDOUTER,BF_RECT);
	}

	//模拟当按钮有焦点时画虚线到按钮上
	CRect RtFocus;

	if (lpDIS->itemState & ODS_FOCUS)
	{
		RtFocus.CopyRect(RtBtn);
		RtFocus.DeflateRect(2,2);
		dc->DrawFocusRect(RtFocus);
	}

	//dc.Detach();//和Attach成对使用
}

3、将按钮的属性Owner Draw设置为TRUE。并为3个绑定控件变量，类型为： CMyButton

CMyButton m_Btn1;
	CMyButton m_Btn2;
	CMyButton m_Btn3;

4、在程序的初始化函数中使用我们自己封装的SetIcon()函数加载我们事先导入的3个图标：

BOOL CListSortDlg::OnInitDialog()
{
	CDialogEx::OnInitDialog();	

	m_Btn1.SetIcon(IDI_ICON1);
	m_Btn2.SetIcon(IDI_ICON2);
	m_Btn3.SetIcon(IDI_ICON4);

	//......