void CMfcdlgDlg::OnButton1()
{
DWORD extstyle;
extstyle = m_list.GetExtendedStyle();
if( (extstyle & LVS_EX_GRIDLINES) == LVS_EX_GRIDLINES)
{
m_list.SetExtendedStyle(extstyle & (~LVS_EX_GRIDLINES));
}
else
{
m_list.SetExtendedStyle(extstyle | LVS_EX_GRIDLINES);
}
}