treeview 的小问题？关于‘+’，‘-’

Question

treeview有好几个imagelist属性设置它们就能如你所愿

Answer 1

type
  TFormHelp = class(TForm)
    TreeViewHelp: TTreeView;
    ImageList1: TImageList;
    procedure TreeViewHelpCollapsed(Sender: TObject; Node: TTreeNode);
    procedure TreeViewHelpExpanded(Sender: TObject; Node: TTreeNode);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  FormHelp: TFormHelp;implementation{$R *.dfm}procedure TFormHelp.TreeViewHelpCollapsed(Sender: TObject;
  Node: TTreeNode);
begin
  TTreeView(Sender).Items.BeginUpdate;
  Node.ImageIndex := 0;
  Node.SelectedIndex := 0;
  TTreeView(Sender).Items.EndUpdate;
end;procedure TFormHelp.TreeViewHelpExpanded(Sender: TObject; Node: TTreeNode);
begin
  TTreeView(Sender).Items.BeginUpdate;
  Node.ImageIndex := 1;
  Node.SelectedIndex := 1;
  TTreeView(Sender).Items.EndUpdate;
end;procedure TFormHelp.FormCreate(Sender: TObject);
var
  I: Integer;
begin
  with TreeViewHelp do for I := 0 to Pred(Items.Count) do
    if Items[I].Count = 0 then begin
      Items[I].ImageIndex := 2;
      Items[I].SelectedIndex := 2;
    end else begin
      Items[I].ImageIndex := 0;
      Items[I].SelectedIndex := 0;
    end;
end;

Answer 2

object FormHelp: TFormHelp
  Left = 192
  Top = 107
  Width = 544
  Height = 375
  Caption = 'FormHelp'
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'MS Sans Serif'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object TreeViewHelp: TTreeView
    Left = 192
    Top = 88
    Width = 200
    Height = 132
    Images = ImageList1
    Indent = 19
    ReadOnly = True
    TabOrder = 0
    OnCollapsed = TreeViewHelpCollapsed
    OnExpanded = TreeViewHelpExpanded
    Items.Data = {
      030000001C0000000000000000000000FFFFFFFFFFFFFFFF0000000000000000
      033131311C0000000000000000000000FFFFFFFFFFFFFFFF0000000000000000
      033232321C0000000000000000000000FFFFFFFFFFFFFFFF0000000002000000
      036464641C0000000000000000000000FFFFFFFFFFFFFFFF0000000000000000
      036363631C0000000000000000000000FFFFFFFFFFFFFFFF0000000001000000
      036666661C0000000000000000000000FFFFFFFFFFFFFFFF0000000000000000
      03646464}
  end
  object ImageList1: TImageList
    Left = 429
    Top = 9
    Bitmap = {
      494C010103000400040010001000FFFFFFFFFF10FFFFFFFFFFFFFFFF424D3600
      000000000000360000002800000040000000100000000100180000000000000C
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000800080800080800080000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000080008000000080808000000000000000000000000000000000000000
      0000000000000000000000800080000000000000800080800080800080800080
      800080800080800080800080000000000000000000000000808080C0C0C0C0C0
      C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      00800080800080000000FFFFFFC0C0C0FFFFFF00000000000000000000000000
      0000000000000000000000800080FFFFFF000000000000000000808080C0C0C0
      C0C0C0FFFFFFFFFFFF800080000000000000000000000000808080FFFFFF00FF
      FFFFFFFFFFFFFFFFFFFF00FFFFFFFFFFFFFFFFFFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000008000
      80800080800080000000808080FFFFFFC0C0C0FFFFFFC0C0C000000000000000
      0000000000000000800080800080FFFFFF000000C0C0C0FFFFFF808080000000
      000000000000FFFFFF800080000000000000000000000000808080FFFFFFFFFF
      FFFFFFFF00FFFFFF0000FF0000FFFFFF00FFFFFFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000008000808000
      80800080800080C0C0C0000000000000808080C0C0C0FFFFFFC0C0C000000000
      0000000000800080800080FFFFFFFFFFFF000000C0C0C0FFFFFFFFFFFFFFFFFF
      00FFFF808080FFFFFF800080000000000000000000000000808080FFFFFF00FF
      FFFFFFFFFFFFFFFF0000FF0000FFFFFFFFFFFFFFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000008000808000808000
      80800080C0C0C0800080800080800080000000000000808080FFFFFF80808000
      0000000000800080FFFFFFFFFFFFFFFFFF000000C0C0C0FFFFFF00FFFFFFFFFF
      FFFFFF808080FFFFFF800080000000000000000000000000808080FFFFFFFFFF
      FFFFFFFF00FFFFFFFFFFFFFFFFFFFFFF00FFFFFFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000008000808000808000808000
      80C0C0C080008080008080008080008080008080008000000000000080808000
      0000000000800080FFFFFFFFFFFFFFFFFF000000C0C0C0FFFFFFFFFFFFFFFFFF
      00FFFF808080FFFFFF800080000000000000000000000000808080FFFFFF00FF
      FFFFFFFFFFFFFFFF0000FF0000FFFFFFFFFFFFFFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      000000000000000000000000000000000000000000800080800080800080C0C0
      C080008080008080008080008080008080008080008080008080008000000000
      0000000000800080FFFFFFFFFFFFFFFFFF000000C0C0C0FFFFFF00FFFFFFFFFF
      FFFFFF808080FFFFFF800080000000000000000000000000808080FFFFFFFFFF
      FFFFFFFF00FFFFFFFFFFFF0000FF000000FFFFFFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      000000000000000000000000000000000000000000800080800080C0C0C08000
      8080008080008080008080008080008080008080008080008080008000000000
      0000000000800080FFFFFFFFFFFFFFFFFF000000C0C0C0FFFFFFFFFFFFFFFFFF
      00FFFF808080FFFFFF800080000000000000000000000000808080FFFFFF00FF
      FFFFFFFFFFFFFFFFFFFF00FFFFFF0000FF0000FFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      000000000000000000000000000000000000000000800080C0C0C08000808000
      8080008080008080008080008080008080008080008080008000000000000000
      0000000000800080FFFFFFFFFFFFFFFFFF000000C0C0C0FFFFFF00FFFFFFFFFF
      FFFFFF808080FFFFFF800080000000000000000000000000808080FFFFFFFFFF
      FFFF0000FF0000FFFFFFFFFFFFFF0000FF0000FFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      000000000000000000000000000000000000000000C0C0C08000808000808000
      8080008080008080008080008080008080008080008000000000000000000000
      0000000000800080FFFFFFFFFFFFC0C0C0808080808080FFFFFFFFFFFFFFFFFF
      00FFFF808080000000000000000000000000000000000000808080FFFFFF00FF
      FFFF0000FF0000FFFFFF00FFFFFF0000FF0000FFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000008000808000
      8080008080008080008080008080008080008000000000000000000000000000
      0000000000800080FFFFFFFFFFFF808080000000000000808080808080FFFFFF
      FFFFFF808080000000000000000000000000000000000000808080FFFFFFFFFF
      FFFFFFFFFF0000FF0000FF0000FF000000FFFFFFFFFFC0C0C000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0080008080008080008080008080008000000000000000000000000000000000
      0000000000800080FFFFFFC0C0C0808080000000000000000000000000808080
      808080808080000000000000000000000000000000000000808080FFFFFF00FF
      FFFFFFFFFFFFFFFFFFFF00FFFFFFFFFFFFFFFF00000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000080008080008000000000000000000000000000000000000000
      0000000000808080C0C0C0808080000000000000000000000000000000000000
      000000000000000000000000000000000000000000000000808080FFFFFFFFFF
      FFFFFFFF00FFFFFFFFFFFFFFFFFFFFFF00FFFF808080808080FFFFFF00000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000000000000000000000
      0000000000000000808080000000000000000000000000000000000000000000
      0000000000000000000000000000000000000000000000008080808080808080
      80808080808080808080808080808080808080808080FFFFFFFFFFFF00000000
      0000000000000000000000000000000000000000000000000000000000000000
      000000000000000000000000000000000000424D3E000000000000003E000000
      2800000040000000100000000100010000000000800000000000000000000000
      000000000000000000000000FFFFFF00FFFFE3FFFFFF0000FC7FC001C0030000
      F81FC001C0030000F007C001C0030000E0018001C0030000C0000001C0030000
      80010001C003000000010001C003000000000001C003000000010001C0030000
      00030001C003000000070003C0030000800F060FC0030000E01F078FC0030000
      F83F8FFFC0030000FE7FDFFFC003000000000000000000000000000000000000
      000000000000}
  end
end