MeasureItem不被调用的这个东西,网上很多朋友都遇到过,在此写出自己的原因。
h
class CListCtrlEx : public CListCtrl
{
DECLARE_DYNAMIC(CListCtrlEx)
public:
CListCtrlEx();
virtual ~CListCtrlEx();
virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
protected:
afx_msg void MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct);
DECLARE_MESSAGE_MAP()
}
.cpp
BEGIN_MESSAGE_MAP(CListCtrlEx, CListCtrl)
ON_WM_MEASUREITEM_REFLECT() //反射回控件
END_MESSAGE_MAP()
void CListCtrlEx::PreSubclassWindow()
{
ModifyStyle(0, LVS_OWNERDRAWFIXED);
CListCtrl::PreSubclassWindow();
}
void CListCtrlEx::MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct)
{
lpMeasureItemStruct->itemHeight = 18;
}
看起来很完美,响应反射消息,而且也设置了LVS_OWNERDRAWFIXED); 我的MeasureItem就是
死活不被调用,看啊,我DrawItem都响应了,为什么,为神马??楼主急了2个多小时,终于
崩溃的发现,原来这个消息还需要被触发的。看下面
void CListCtrlEx::PreSubclassWindow()
{
ModifyStyle(0, LVS_OWNERDRAWFIXED);
CListCtrl::PreSubclassWindow();
CRect rcWin;
GetWindowRect(&rcWin);
WINDOWPOS wp;
wp.hwnd = m_hWnd;
wp.cx = rcWin.Width();
wp.cy = rcWin.Height();
wp.flags = SWP_NOACTIVATE | SWP_NOMOVE | SWP_NOOWNERZORDER | SWP_NOZORDER;
SendMessage(WM_WINDOWPOSCHANGED, 0, (LPARAM)&wp); //发消息触发MeasureItem。OK
}
当然你也可以这样写:
.h
void SetRowHeight(int nHeight);
.cpp
void CListCtrl::SetRowHeight(int nHeight)
{
m_height = nHeight;
CRect rcWin;
GetWindowRect(&rcWin);
WINDOWPOS wp;
wp.hwnd = m_hWnd;
wp.cx = rcWin.Width();
wp.cy = rcWin.Height();
wp.flags = SWP_NOACTIVATE | SWP_NOMOVE | SWP_NOOWNERZORDER | SWP_NOZORDER;
SendMessage(WM_WINDOWPOSCHANGED, 0, (LPARAM)&wp);
}
void CListCtrlEx::MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct)
{
lpMeasureItemStruct->itemHeight = m_height ;
}