关于delphi treeview加选择框

Question

大家好！前面看了万一老师的博客，用
SetWindowLong(H, GWL_STYLE, GetWindowLong(H, GWL_STYLE) or TVS_CHECKBOXES)
实现在treeview前加选择框。试了一下，可以，不过我有一个疑问，如何用代码控制将某个节点置为“选中”或“未选中”状态呢？我的目的是想，在某个节点状态改变（选中或未选中）时，自动改变父节点和子节点的状态。
谢谢！

Answer 1

把treeview和imagelist结合起来使用，很方便的就可以达到楼主想要的效果。

Answer 2

就是修改TreeView的StateIndex来改变选中未选中，ImageList中添加2个图标，一个是不打勾的，一个打勾的，然后改StateIndex就可以

Answer 3

1stClass 里面有这样的组件

Answer 4

曾经写过的一个控件unit CheckedTreeView;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ComCtrls, Commctrl;type
  TTVCheckChangedEvent = procedure(Sender: TObject; Node: TTreeNode; Checked: boolean) of object;
  TCheckedTreeView = class(TTreeView)
  private
    { Private declarations }  protected
    { Protected declarations }
    F_OnNodeCheckChanged: TTVCheckChangedEvent;  //当一个Node的Checked属性发生变化后触发
    F_CheckedNodeList: TList;               //纪录所有被Checked的节点
    F_CheckBoxes: Boolean;                  //是否显示CheckBox
    //某个Node被选中或反选后触发
    procedure Do_NodeChecked(node: TTreeNode; checked: Boolean);virtual;
    procedure CNNotify(var Message: TWMNotify); message CN_NOTIFY;
    procedure SetCheckBoxes(value: Boolean);
    function GetNodeFromItem(const Item: TTVItem): TTreeNode;
    procedure Delete(Node: TTreeNode); override;
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    function NodeChecked(node: TTreeNode): boolean;
    procedure CheckNode(Node :TTreeNode; Checked :Boolean);
  published
    { Published declarations }
    property OnNodeCheckedChanged: TTVCheckChangedEvent read F_OnNodeCheckChanged write F_OnNodeCheckChanged;
    property CheckBoxes: boolean read F_CheckBoxes write SetCheckBoxes;
  end;function IsNodeChecked(node: TTreeNode): boolean;
procedure SetNodeChecked(Node :TTreeNode; Checked :Boolean);
procedure Register;implementationconst
      TVIS_CHECKED = $2000;
      TVIS_UNCHECKED = $1000;
      TVS_CHECKBOXES = $0100;procedure Register;
begin
  RegisterComponents('Samples', [TCheckedTreeView]);
end;
procedure SetComCtlStyle(Ctl: TWinControl; Value: Integer; UseStyle: Boolean);
var
  Style: Integer;
begin
    if Ctl.HandleAllocated  then
    begin
        Style := GetWindowLong(Ctl.Handle, GWL_STYLE);
        if   not   UseStyle   then
            Style := Style and (not Value)
        else
            Style := Style or Value;
        SetWindowLong(Ctl.Handle, GWL_STYLE, Style);
    end;
end;function IsNodeChecked(node: TTreeNode): boolean;
var
    TvItem:TTVItem;
begin
    TvItem.Mask := TVIF_STATE;
    TvItem.hItem := Node.ItemId;
    TreeView_GetItem(Node.TreeView.Handle, TvItem);
    Result := (TvItem.State and TVIS_CHECKED) = TVIS_CHECKED;
end;procedure SetNodeChecked(Node :TTreeNode; Checked :Boolean);
var
    TvItem:TTVItem;
begin
    FillChar(TvItem,   SizeOf(TvItem),   0);
    with TvItem do
    begin
        hItem :=Node.ItemId;
        Mask := TVIF_STATE;
        StateMask := TVIS_STATEIMAGEMASK;
        if Checked  then
            TvItem.State:= (TvItem.State and (not TVIS_UNCHECKED)) or TVIS_CHECKED
        else
            TvItem.State:=(TvItem.State and (not TVIS_CHECKED)) or TVIS_UNCHECKED;
        TreeView_SetItem(Node.TreeView.Handle, TvItem);
    end;
end;{ TCheckedTreeView }procedure TCheckedTreeView.CNNotify(var Message: TWMNotify);
var
    bOriginalChecked: Boolean;
    bCurrentChecked: Boolean;
    nIndex: Integer;
    node: TTreeNode;
begin
    inherited;
    With Message do
    begin
        case NMHdr^.code of
            TVN_GETDISPINFO:
            begin
                with PTVDispInfo(NMHdr)^ do
                begin
                    Node := GetNodeFromItem(item);
                    bCurrentChecked:= IsNodeChecked(node);
                    nIndex:= F_CheckedNodeList.IndexOf(node);
                    if nIndex >= 0 then
                        bOriginalChecked:= true
                    else
                        bOriginalChecked:= false;                    if bOriginalChecked <> bCurrentChecked then
                    begin
                        if bCurrentChecked then
                            F_CheckedNodeList.Add(node)
                        else
                            F_CheckedNodeList.Delete(nIndex);
                        Do_NodeChecked(node, bCurrentChecked);
                    end ;
                end ;
            end;
        end ; //case
    end;
end ;
constructor TCheckedTreeView.Create(AOwner: TComponent);
begin
  inherited;
  F_CheckBoxes:= false;
  F_CheckedNodeList:= TList.Create;
end;destructor TCheckedTreeView.Destroy;
begin
  F_CheckedNodeList.Clear;
  F_CheckedNodeList.Free;
  inherited;end;function TCheckedTreeView.NodeChecked(node: TTreeNode): boolean;
begin
    Result:= IsNodeChecked(node);
end ;procedure TCheckedTreeView.CheckNode(Node :TTreeNode; Checked :Boolean);
var
    nIndex: Integer;
begin
    SetNodeChecked(node, checked);
    nIndex:= F_CheckedNodeList.IndexOf(node);
    if checked and (nIndex< 0) then
    begin
        F_CheckedNodeList.Add(Node);
        Do_NodeChecked(node, checked);
    end
    else if (not checked) and (nIndex>=0 ) then
    begin
        F_CheckedNodeList.Delete(nIndex);
        Do_NodeChecked(node, checked);
    end ;
end ;procedure TCheckedTreeView.Do_NodeChecked(node: TTreeNode;
  checked: Boolean);
begin
    if  F_CheckBoxes then
        if Assigned(F_OnNodeCheckChanged) then
            F_OnNodeCheckChanged(self,node, checked);
end;function TCheckedTreeView.GetNodeFromItem(const Item: TTVItem): TTreeNode;
begin
  Result := nil;
  if Items <> nil then
    with Item do
      if (state and TVIF_PARAM) <> 0 then Result := Pointer(lParam)
      else Result := Items.GetNode(hItem);
end;procedure TCheckedTreeView.SetCheckBoxes(value: Boolean);
var
    nIndex: Integer;
    TvItem:TTVItem;
begin
    if Value<> F_CheckBoxes then
    begin
        F_CheckBoxes:= value;
        if value then
            SetComCtlStyle(Self,TVS_CHECKBOXES,True)
        else
        begin
            SetComCtlStyle(Self,TVS_CHECKBOXES,False);
            F_CheckedNodeList.Clear ;
            //Update all nodes' state to remove the boxes
            for nIndex := 0 to Items.Count -1 do
            begin
                FillChar(TvItem, SizeOf(TvItem),   0);
                with TvItem do
                begin
                    hItem :=Items.Item[nIndex].ItemId;
                    Mask := TVIF_STATE;
                    StateMask := TVIS_STATEIMAGEMASK;
                    TreeView_GetItem(Handle, TvItem);
                    TVItem.State:= TVItem.state and (Not TVIS_UNCHECKED) and (Not TVIS_CHECKED);
                    TreeView_SetItem(Handle, TvItem);
                end;            end ;
        end ;    end ;
end ;procedure TCheckedTreeView.Delete(Node: TTreeNode);
var
    nIndex: Integer;
begin
    nIndex:= F_CheckedNodeList.IndexOf(node);
    if nIndex >= 0 then
        F_CheckedNodeList.Delete(nIndex);
    inherited;
end;end.