学习 TTreeView [8] - AlphaSort、CustomSort、SortType

本例效果图:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, StdCtrls;

type
  TForm1 = class(TForm)
    TreeView1: TTreeView;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{初始化}
procedure TForm1.FormCreate(Sender: TObject);
var
  stream: TMemoryStream;
begin
  TreeView1.Align := alLeft;
  stream := TMemoryStream.Create;
  with TStringList.Create do
  begin
    Add('2');
    Add('3');
    Add('1');
    Add('4');
    Add(#32'2');
    Add(#32'3');
    Add(#32'1');
    Add(#32'4');
    Add(#32#32'2');
    Add(#32#32'3');
    Add(#32#32'1');
    Add(#32#32'4');
    SaveToStream(stream);
    Free;
  end;
  stream.Position := 0;
  TreeView1.LoadFromStream(stream);
  TreeView1.SortType := stNone;
  stream.Free;

  Button1.Caption := '排序第一层';
  Button2.Caption := '全部排序';
  Button3.Caption := '指定排序类型';
  Button4.Caption := '倒排序';
  Button5.Caption := '初始化';
end;

{只排序第一层}
procedure TForm1.Button1Click(Sender: TObject);
begin
  TreeView1.AlphaSort(False);
end;

{全部排序}
procedure TForm1.Button2Click(Sender: TObject);
begin
  TreeView1.AlphaSort;
end;

{指定排序类型}
procedure TForm1.Button3Click(Sender: TObject);
begin
  TreeView1.SortType := stText;

{SortType 有四种选择:
  stNone, stData, stText, stBoth
  stText 表示按显示的标签文本排序.
}
end;

{倒排序}
procedure TForm1.Button4Click(Sender: TObject);
  function MySort(Node1, Node2: TTreeNode; lParam: Integer): Integer; stdcall;
  begin
    Result := -AnsiStrIComp(PChar(Node1.Text), PChar(Node2.Text));
  end;
begin
  TreeView1.CustomSort(@MySort, 0);
end;

{重新初始化}
procedure TForm1.Button5Click(Sender: TObject);
begin
  FormCreate(nil);
end;

end.