关于OnEnter的一点小问题
两个DBGRID分别有两个DATASOURCE,这两个DBGrid用一个DBNavigator来控制,当选中DBGrid1时DBNavigator控制DBGrid1,当选中DBGrid2时DBNavigator1控制DBGrid2;
方法是:在DBGrid1的OnEnter事件中添加如下代码:
if Sender = DBGrid1 then
DBNavigator1.DataSource:=DBGrid1.DataSource
else
DBNavigator1.DataSource:=DBGrid2.DataSource;
然后再把DBGrid2的OnEnter事件设为DBGrid2Enter
这样就可以实现用一个导航条控制两个DBGrid了.
我想问的问题是:
if Sender = DBGrid1 then
DBNavigator1.DataSource:=DBGrid1.DataSource
else
DBNavigator1.DataSource:=DBGrid2.DataSource;
这段代码中已经有了else语句来判断当DBGrid1没有选中时DBNavigator1.DataSource:=DBGrid2.DataSource
那么为什么还要再设置DBGrid2的OnEnter为DBGrid2Enter?这样岂不是重复了?但事实却是必须把DBGrid2的OnEnter写为DBGrid2Enter须把DBGrid2的OnEnter写为DBGrid2Enter.
这是为什么?