更改TTreeView控件

Question

这是我在网上查的东东：由于Delphi自带的TTreeView里并没有复选框的功能。因此，必须重新设计控件。 
在设计时因TTreeView里有一个StateIndex和StateImages，而纵观TTreeView的代码可以知道它只是发布了一下TCustomTreeView定义并实现好的属性和方法而已。因此我们也选择TCustomTreeView为TCheckTree控件的祖先类。 
重要的实现技术为： 
procedure TCheckTree.WMPaint( var Msg: TWMPaint ); 
var 
I: Integer; 
begin 
for I := 0 to Items.Count - 1 do 
begin 
if not(Items[ I ].StateIndex in [Ord(csUnknown)..Ord(csPartiallyChecked)]) then 
Items[ I ].StateIndex := Ord(csUnchecked) //这里我修改了 
end; 
inherited; 
end; 
function TCheckTree.GetItemState( Node:TTreeNode ): TCheckCheckState; 
begin 
Result := TCheckCheckState( Node.StateIndex ); 
end; 
procedure TCheckTree.SetItemState( Node:TTreeNode; Value: TCheckCheckState ); 
begin 
if TCheckCheckState( Node.StateIndex ) <> Value then 
ChangeNodeCheckState( Node, Value ); 
end; 
procedure TCheckTree.StateChange( Node: TTreeNode; NewState: TCheckCheckState ); 
begin 
if Assigned( FOnStateChange ) then 
FOnStateChange( Self, Node, NewState ); 
end; 我刚开始学delphi ,需要这个修改后的控件，那位大哥能不能修改后发给我，或者告诉我具体的修改方法（本人比较菜，详细点）
,谢谢各位高手了！！！！！

Answer 1

标准treeview也可以带复选框
http://www.cnblogs.com/del/archive/2008/05/15/1198645.html

Answer 2

这个是我用的代码，拿过去建个组件包，然后安装一下就可以了。unit DLCheckboxTreeView;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ComCtrls, Commctrl, StdCtrls;
  
type{ TDLCheckTreeView }  TDLStateChangeEvent = procedure (Sender: TObject; Node: TTreeNode;
    OldState, NewState: TCheckBoxState) of object;  TDLCheckTreeView = class(TTreeView)
  private
    { Private declarations }
    FStateImages: TImageList;
    FUpdateCount: Integer;
    FOnStateChange: TDLStateChangeEvent;
    function GetCheckBoxState(Node: TTreeNode): TCheckBoxState;
    procedure SetCheckBoxState(Node: TTreeNode;
      const Value: TCheckBoxState);
    function GetChecked(Node: TTreeNode): Boolean;
    procedure SetChecked(Node: TTreeNode; const Value: Boolean);
  protected
    { Protected declarations }
    procedure WndProc(var message: TMessage); override;
    procedure KeyPress(var Key: Char); override;
    procedure Loaded; override;
    function ToggleCheckedByPos(x, y: Integer): Boolean;
    function ToggleChecked(Node: TTreeNode): Boolean;
    procedure SyncChildNode(Node: TTreeNode);
    procedure SyncParentNode(Node: TTreeNode);
    procedure SetUpdateState(Updating: Boolean);
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure BeginUpdate;
    procedure EndUpdate;
    procedure SyncNodes;
    procedure SelectAll;
    procedure SelectNone;
    procedure SelectInvert;    property CheckBoxState[Node: TTreeNode]: TCheckBoxState read GetCheckBoxState
      write SetCheckBoxState;
    property Checked[Node: TTreeNode]: Boolean read GetChecked write SetChecked;
  published
    property OnStateChange: TDLStateChangeEvent read FOnStateChange write FOnStateChange;
  end;procedure Register;implementation{$R DLCheckboxTreeView.res}procedure Register;
begin
  RegisterComponents('SQLDebug_Fan', [TDLCheckTreeView]);
end;{ TDLCheckTreeView }constructor TDLCheckTreeView.Create(AOwner: TComponent);
begin
  inherited;
  FStateImages := TImageList.CreateSize(16, 16);
  FStateImages.Handle := ImageList_LoadBitmap(hInstance, 'CNTREEVIEWSTATE',
    16, 0, clFuchsia);
  StateImages := FStateImages;
end;destructor TDLCheckTreeView.Destroy;
begin
  FStateImages.Free;
  inherited;
end;procedure TDLCheckTreeView.Loaded;
begin
  inherited Loaded;
  SyncNodes;
end;function TDLCheckTreeView.GetCheckBoxState(Node: TTreeNode): TCheckBoxState;
begin
  if Node.StateIndex in [1..3] then
    Result := TCheckBoxState(Node.StateIndex - 1)
  else
    Result := cbUnchecked;
end;procedure TDLCheckTreeView.SetCheckBoxState(Node: TTreeNode;
  const Value: TCheckBoxState);
var
  OldState: TCheckBoxState;
begin
  // 不允许手工设置部分选择状态
  if (Node.StateIndex - 1 <> Ord(Value)) and (Value <> cbGrayed) then
  begin
    OldState := TCheckBoxState(Node.StateIndex - 1);
    Node.StateIndex := Ord(Value) + 1;
    if FUpdateCount = 0 then
    begin
      SyncChildNode(Node);
      SyncParentNode(Node);
      if Assigned(FOnStateChange) then
        FOnStateChange(Self, Node, OldState, Value);
    end;      
  end;
end;function TDLCheckTreeView.GetChecked(Node: TTreeNode): Boolean;
begin
  Result := GetCheckBoxState(Node) = cbChecked;
end;procedure TDLCheckTreeView.SetChecked(Node: TTreeNode;
  const Value: Boolean);
begin
  if Value then
    SetCheckBoxState(Node, cbChecked)
  else
    SetCheckBoxState(Node, cbUnchecked);
end;function TDLCheckTreeView.ToggleChecked(Node: TTreeNode): Boolean;
begin
  if Assigned(Node) then
  begin
    SetChecked(Node, not GetChecked(Node));
    Result := True;
  end
  else
    Result := False;
end;function TDLCheckTreeView.ToggleCheckedByPos(x, y: Integer): Boolean;
var
  Node: TTreeNode;
begin
  Result := False;
  if htOnStateIcon in GetHitTestInfoAt(x, y) then
  begin
    Node := GetNodeAt(x, y);
    Result := ToggleChecked(Node);
  end;
end;procedure TDLCheckTreeView.KeyPress(var Key: Char);
begin
  if (Key = ' ') and Assigned(Selected) then
    ToggleChecked(Selected)
  else
    inherited;
end;procedure TDLCheckTreeView.SyncNodes;
var
  i: Integer;  function DoSyncNodeState(Node: TTreeNode): TCheckBoxState;
  var
    SelCount, UnSelCount, Count: Integer;
    ChildNode: TTreeNode;
  begin
    ChildNode := Node.GetFirstChild;
    if ChildNode <> nil then
    begin
      SelCount := 0;
      UnSelCount := 0;
      Count := 0;
      while ChildNode <> nil do
      begin
        if DoSyncNodeState(ChildNode) = cbChecked then
          Inc(SelCount)
        else if DoSyncNodeState(ChildNode) = cbUnchecked then
          Inc(UnSelCount);
        Inc(Count);
        ChildNode := Node.GetNextChild(ChildNode);
      end;      if SelCount = Count then
      begin
        if Node.StateIndex <> Ord(cbChecked) + 1 then
          Node.StateIndex := Ord(cbChecked) + 1;
      end
      else if UnSelCount = Count then
      begin
        if Node.StateIndex <> Ord(cbUnchecked) + 1 then
          Node.StateIndex := Ord(cbUnchecked) + 1;
      end
      else if Node.StateIndex <> Ord(cbGrayed) + 1 then
      begin
        Node.StateIndex := Ord(cbGrayed) + 1;
      end;
    end
    else if not (Node.StateIndex in [1..3]) then
    begin
      Node.StateIndex := Ord(cbUnchecked) + 1;
    end;    Result := GetCheckBoxState(Node);
  end;
begin
  for i := 0 to Items.Count - 1 do
    DoSyncNodeState(Items[i]);
end;// 同步子节点状态，子节点拷贝父节点状态
procedure TDLCheckTreeView.SyncChildNode(Node: TTreeNode);
var
  i: Integer;
begin
  if Node.StateIndex <> Ord(cbGrayed) + 1 then
    for i := 0 to Node.Count - 1 do
    begin
      Node.Item[i].StateIndex := Node.StateIndex;
      SyncChildNode(Node.Item[i]);
    end;
end;// 同步父节点状态, 父节点拷贝子节点状态
procedure TDLCheckTreeView.SyncParentNode(Node: TTreeNode);
var
  SelCount, UnSelCount, Count: Integer;
  ParentNode, ChildNode: TTreeNode;
begin
  ParentNode := Node.Parent;
  if ParentNode <> nil then
  begin
    SelCount := 0;
    UnSelCount := 0;
    Count := 0;
    ChildNode := ParentNode.GetFirstChild;
    while ChildNode <> nil do
    begin
      if GetCheckBoxState(ChildNode) = cbChecked then
        Inc(SelCount)
      else if GetCheckBoxState(ChildNode) = cbUnchecked then
        Inc(UnSelCount);
      Inc(Count);
      ChildNode := ParentNode.GetNextChild(ChildNode);
    end;    if SelCount = Count then
    begin
      if ParentNode.StateIndex <> Ord(cbChecked) + 1 then
      begin
        ParentNode.StateIndex := Ord(cbChecked) + 1;
        SyncParentNode(ParentNode);
      end;
    end
    else if UnSelCount = Count then
    begin
      if ParentNode.StateIndex <> Ord(cbUnchecked) + 1 then
      begin
        ParentNode.StateIndex := Ord(cbUnchecked) + 1;
        SyncParentNode(ParentNode);
      end;
    end
    else if ParentNode.StateIndex <> Ord(cbGrayed) + 1 then
    begin
      ParentNode.StateIndex := Ord(cbGrayed) + 1;
      SyncParentNode(ParentNode);
    end;
  end;
end;procedure TDLCheckTreeView.WndProc(var message: TMessage);
begin
  case message.Msg of
    WM_LBUTTONDOWN, WM_LBUTTONDBLCLK:
      begin
        if ToggleCheckedByPos(TWMLButtonDown(message).XPos, TWMLButtonDown(message).YPos)
          then
          Exit;
      end;
    WM_LBUTTONUP, WM_RBUTTONUP:
      begin
        if htOnStateIcon in GetHitTestInfoAt(TWMLButtonDown(message).XPos,
          TWMLButtonDown(message).YPos) then
          Exit;
      end;
  end;
  inherited WndProc(message);
end;procedure TDLCheckTreeView.BeginUpdate;
begin
  Items.BeginUpdate;
  if FUpdateCount = 0 then SetUpdateState(True);
  Inc(FUpdateCount);
end;procedure TDLCheckTreeView.EndUpdate;
begin
  Dec(FUpdateCount);
  if FUpdateCount = 0 then SetUpdateState(False);
  Items.EndUpdate;
end;procedure TDLCheckTreeView.SetUpdateState(Updating: Boolean);
begin
  if not Updating then
    SyncNodes;
end;procedure TDLCheckTreeView.SelectAll;
var
  Node: TTreeNode;
begin
  Items.BeginUpdate;
  try
    Node := Items.GetFirstNode;
    while Node <> nil do
    begin
      Node.StateIndex := Ord(cbChecked) + 1;
      Node := Node.GetNext;
    end;
  finally
    Items.EndUpdate;
  end;          
end;procedure TDLCheckTreeView.SelectNone;
var
  Node: TTreeNode;
begin
  Items.BeginUpdate;
  try
    Node := Items.GetFirstNode;
    while Node <> nil do
    begin
      Node.StateIndex := Ord(cbUnchecked) + 1;
      Node := Node.GetNext;
    end;
  finally
    Items.EndUpdate;
  end;
end;procedure TDLCheckTreeView.SelectInvert;
var
  Node: TTreeNode;
begin
  Items.BeginUpdate;
  try
    Node := Items.GetFirstNode;
    while Node <> nil do
    begin
      if Node.StateIndex = Ord(cbUnchecked) + 1 then
        Node.StateIndex := Ord(cbChecked) + 1
      else if Node.StateIndex = Ord(cbChecked) + 1 then
        Node.StateIndex := Ord(cbUnchecked) + 1;
      Node := Node.GetNext;
    end;
  finally
    Items.EndUpdate;
  end;          
end;end.

Answer 3

或者CnPack的组件包中也有一个带的CheckBox的TreeView，哪个有组件包，你安装一下就可以了。

Answer 4

标准treeview也可以带复选框 
http://www.cnblogs.com/del/archive/2008/05/15/1198645.html
万一的博客，有例子的，可以学习看一下。

Answer 5

错！Delphi自带的TTreeView里有复选框的功能！执行这句：
SetWindowLong(TreeView1.Handle, GWL_STYLE, GetWindowLong(TreeView1.Handle, GWL_STYLE) or TVS_CHECKBOXES);就有复选框了。但你如果想判断是否被选中等，用楼上几位提供的方法即可。