Question

DELPHI谁能帮我解释这段简单代码含义

我现在在做城市公交查询系统 这个模块的作用是将比较前两个查询结果 如果有相同就输出结果 代码是:
procedure TForm4.Button2Click(Sender: TObject);
begin
Form5.Label1.Caption:='';
Form5.Show;
Form4.Hide;
从这里开始能帮我简单解释下代码的含义 (刚刚开始学这个 又要弄毕业设计 准备要把这个弄的论文里的)
Form3.ADOTable1.Last;
Form4.ADOTable1.Last;
last1:=Form3.ADOTable1.Fields[1].AsString;
last2:=Form4.ADOTable1.Fields[1].AsString;
Form3.ADOTable1.First;
repeat
Form4.ADOTable1.First;
repeat
if Form3.ADOTable1.Fields[1].AsString=Form4.ADOTable1.Fields[1].AsString
then
begin
Form5.Label1.Caption:=Form5.Label1.Caption+Form4.ADOTable1.Fields[1].AsString+',';
end;
Form4.ADOTable1.Next;
until Form4.adoTable1.Fields[1].AsString=last2;
if Form3.ADOTable1.Fields[1].AsString=Form4.ADOTable1.Fields[1].AsString
then
begin
Form5.Label1.Caption:=Form5.Label1.Caption+Form4.ADOTable1.Fields[1].AsString+',';
end;
Form3.ADOTable1.Next;
until Form3.ADOTable1.Fields[1].AsString=last1;
Form4.ADOTable1.First;
repeat
if Form3.ADOTable1.Fields[1].AsString=Form4.ADOTable1.Fields[1].AsString
then
begin
Form5.Label1.Caption:=Form5.Label1.Caption+Form4.ADOTable1.Fields[1].AsString+',';
end;
Form4.ADOTable1.Next;
until Form4.ADOTable1.Fields[1].AsString=last2;
if Form3.ADOTable1.Fields[1].AsString=Form4.ADOTable1.Fields[1].AsString
then
begin
Form5.Label1.Caption:=Form5.Label1.Caption+Form4.ADOTable1.Fields[1].AsString+',';
end;
if Form5.Label1.Caption<>''
then Form5.Label1.Caption:='可选择'+Form5.Label1.Caption+'直达';
end;

Answer 1

全部解释的话要花一点时间,这样吧,我把关键的东西说一下吧
Form3.ADOTable1.Last; //指向table的最后一条记录
last1:=Form3.ADOTable1.Fields[1].AsString; //取字段
Form3.ADOTable1.First; //指向第一条记录
Form4.ADOTable1.Next; //将记录指向下一条
这里的form都是指相对应的form里的adotable