BeDate:=StrtoDate(trim(Edit1.Text)+'-'+trim(EDit2.Text)+'-'+trim(Edit3.Text));
EnDate:=StrtoDate(trim(Edit4.Text)+'-'+trim(EDit5.Text)+'-'+trim(Edit6.Text));
if EnDate<BeDate then
Application.MessageBox('开始日期必须小于结束日期!','错误:',MB_OK)
else
begin
ReDate:=EnDate-BeDate;
DecodeDate(ReDate,Year,Month,Day);
Edit7.Text:=string(Year)+'年'+String(Month)+'月'+String(Day)+'日';//该行应该如何写类型转换??????
end;