TStringList 常用操作(转自南山古陶)

//TStringList 常用方法与属性:

var

  List: TStringList;

  i: Integer;

begin

  List := TStringList.Create;

  List.Add('Strings1');           {添加}

  List.Add('Strings2');

  List.Exchange(0,1);             {置换}

  List.Insert(0,'Strings3');      {插入}

  i := List.IndexOf('Strings1');  {第一次出现的位置}

  List.Sort;                      {排序}

  List.Sorted := True;    {指定排序}

  List.Count;                     {总数}

  List.Text;                      {文本集合}

  List.Delete(0);                 {删除, 0是第一个数据}

  List.LoadFromFile('c:\tmp.txt');{打开}

  List.SaveToFile('c:\tmp.txt');  {保存}

  List.Clear;                     {清空}

  List.Free;                      {释放}

end;


   
     




//读入字符串

var

  List: TStringList;

begin

  List := TStringList.Create;

  List.CommaText := 'aaa,bbb,ccc,ddd';

  //相当于: List.Text := 'aaa' + #13#10 + 'bbb' + #13#10' + 'ccc' + '#13#10' + 'ddd';



  ShowMessage(IntToStr(List.Count));  //4

  ShowMessage(List[0]);  //aaa



  List.Free;

end;


   
     




//置换分隔符

var

  List: TStringList;

begin

  List := TStringList.Create;

  List.Delimiter := '|';

  List.DelimitedText := 'aaa|bbb|ccc|ddd';



  ShowMessage(IntToStr(List.Count));  //4

  ShowMessage(List[0]);  //aaa



  List.Free;

end;


   
     




//类似的哈希表操作法

var

  List: TStringList;

begin

  List := TStringList.Create;



  List.Add('aaa=111');

  List.Add('bbb=222');

  List.Add('ccc=333');

  List.Add('ddd=444');



  ShowMessage(List.Names[1]);  //bbb

  ShowMessage(List.ValueFromIndex[1]);  //222

  ShowMessage(List.Values['bbb']);  //222



  //ValueFromIndex 可以赋值:

  List.ValueFromIndex[1] := '2';

  ShowMessage(List[1]);  //bbb=2



  //可以通过 Values 赋值:

  List.Values['bbb'] := '22';

  ShowMessage(List[1]);  //bbb=22



  List.Free;

end;


   
     




//避免重复值

var

  List: TStringList;

begin

  List := TStringList.Create;



  List.Add('aaa');



  List.Sorted := True;  //需要先指定排序

  List.Duplicates := dupIgnore;  //如有重复值则放弃



  List.Add('aaa');



  ShowMessage(List.Text);  //aaa



  //Duplicates 有3个可选值:

  //dupIgnore: 放弃;

  //dupAccept: 结束;

  //dupError: 提示错误.



  List.Free;

end;


   
     




//排序与倒排序

{排序函数}

function DescCompareStrings(List: TStringList; Index1, Index2: Integer): Integer;

begin

  Result := -AnsiCompareText(List[Index1], List[Index2]);

end;



procedure TForm1.Button1Click(Sender: TObject);

var

  List: TStringList;

begin

  List := TStringList.Create;



  List.Add('bbb');

  List.Add('ccc');

  List.Add('aaa');



  //未排序

  ShowMessage(List.Text);  //bbb ccc aaa



  //排序

  List.Sort;

  ShowMessage(List.Text);  //aaa bbb ccc



  //倒排序

  List.CustomSort(DescCompareStrings);  //调用排序函数

  ShowMessage(List.Text);  //ccc bbb aaa



  //假如:

  List.Sorted := True;

  List.Add('999');

  List.Add('000');

  List.Add('zzz');

  ShowMessage(List.Text);  //000 999 aaa bbb ccc zzz

end;