【delphi】TStringList类常用属性方法详解

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(,);             {置换}
  List.Insert(,'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();                 {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)); {}
  ShowMessage(List[]);  {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)); {}
  ShowMessage(List[]);  {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[]); {bbb}
  ShowMessage(List.ValueFromIndex[]);  {}
  ShowMessage(List.Values['bbb']);  {}

 {ValueFromIndex 可以赋值:}
  List.ValueFromIndex[] := '';
  ShowMessage(List[]);  {bbb=2}

  {可以通过 Values 赋值:}
  List.Values['bbb'] := '';
  ShowMessage(List[]);  {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('');
  List.Add('');
  List.Add('zzz');
  ShowMessage(List.Text);  {000 999 aaa bbb ccc zzz}
end;