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list循环有关问题

发布时间: 2012-05-22 18:18:54 作者: rapoo

list循环问题
如果列表为空

for i:=0 to list.count -1
这样就不循环了
如果不减一,又怕越界,怎么办?

[解决办法]

Delphi(Pascal) code
  repeat    ShowMessage('aa');  until list.count = 0 ;
[解决办法]
既然是空的.还循环它做啥?

想要空的也至少循环一次,那就用repeat until
[解决办法]

Delphi(Pascal) code
if List.Count > 0 then  for i:=0 to list.count -1  begin    {......}  end;
[解决办法]
其实用 for in 比较好一点
Delphi(Pascal) code
procedure TForm1.Button1Click(Sender: TObject);var  List: TStringList;  s: string;begin  List := TStringList.Create;  for s in List do    ShowMessage(s);  List.Free;end;procedure TForm1.Button2Click(Sender: TObject);var  List: TList;  p: Pointer;begin  List := TList.Create;  for p in List do    ShowMessage(IntToStr(Integer(P)));  List.Free;end;
[解决办法]
for i:= list.count -1 downto 0 do
[解决办法]
Delphi(Pascal) code
i := 0;repeat  ShowMessage(IntToStr(i));  Inc(i)until i > list.count-1;
[解决办法]
for in 得高版本的才支持

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