WTL：如何绘制ComboBox

来源：互联网发布：linux 复制文件夹编辑：程序博客网时间：2024/06/01 23:11

首先给大家介绍一个csdn博客关于ComboBox的组成和如何绘制的介绍。

http://blog.csdn.net/fengbangyue/article/details/5222124

我要绘制的是drop list模式的ComboBox。

直接上代码：

//下拉列表框class ComboBox : public CWindowImpl<ComboBox,CComboBox>,public COwnerDraw<ComboBox>{public:BEGIN_MSG_MAP(ComboBox)MSG_WM_ERASEBKGND(OnEraseBkgnd)MSG_WM_PAINT(OnPaint)CHAIN_MSG_MAP_ALT(COwnerDraw<ComboBox>,1)DEFAULT_REFLECTION_HANDLER()END_MSG_MAP()BOOL OnEraseBkgnd(CDCHandle dc){return TRUE;}void OnPaint(CDCHandle)//绘制那个按钮{CPaintDC dc(m_hWnd);CRect rc;GetClientRect(&rc);HBRUSH hBrush = CreateSolidBrush(RGB(200,200,250));dc.FillRect(&rc,hBrush);TCHAR str[255];GetWindowTextW(str,255);if(CString(str).IsEmpty() == FALSE){CFont font;font.CreatePointFont(110,L"华文行楷");dc.SelectFont(font);dc.SetBkMode(TRANSPARENT);rc.left += 5;dc.DrawTextW(str,-1,&rc,DT_VCENTER | DT_SINGLELINE | DT_LEFT);}DeleteObject(hBrush);}void DrawItem(LPDRAWITEMSTRUCT lpdis){//ATLTRACE("ComboBox::DrawItem\r\n");int index = lpdis->itemID;if(index < 0)return;CDCHandle dc(lpdis->hDC);CRect rc = lpdis->rcItem;TCHAR sz[255] = { 0 };GetLBText(index,sz);if(lpdis->itemState & ODS_SELECTED){dc.Draw3dRect(&rc,RGB(0,0,255),RGB(0,0,255));dc.SetTextColor(RGB(200,0,0));}else{HBRUSH hBrush = CreateSolidBrush(RGB(255,255,255));dc.FillRect(&rc,hBrush);dc.SetTextColor(RGB(0,0,0));DeleteObject(hBrush);}dc.SetBkMode(TRANSPARENT);rc.left += 5;dc.DrawTextW(sz,-1,&rc,DT_VCENTER | DT_SINGLELINE | DT_LEFT);}void MeasureItem(LPMEASUREITEMSTRUCT lpmis){//ATLTRACE("ComboBox::MeasureItem\r\n");if(lpmis->itemID < 0)//是按钮lpmis->itemHeight = 25;//如果是子类化，改动无效elselpmis->itemHeight = 25;}};

效果如下：