修改Listctrl的显示Style

//if the current style is not report, the following three lines is not need

GetListCtrl().DeleteAllItems();
for(int h=GetListCtrl().GetHeaderCtrl()->GetItemCount();h>0;h--)
        GetListCtrl().DeleteColumn(h-1);
LONG lStyle;

//Get current window style
lStyle=GetWindowLong(GetListCtrl().GetSafeHwnd(),GWL_STYLE);

//Clear original type mask

lStyle &= ~LVS_TYPEMASK;
//Add new type style,the sample is icon

lStyle|=LVS_ICON;

//Ok,set new type style
SetWindowLong(GetListCtrl().GetSafeHwnd(),GWL_STYLE,lStyle);