怎么让TreeView前面显示CheckBox. 急!在线等! ( 积分: 100 )

  • 主题发起人 主题发起人 czj_earth
  • 开始时间 开始时间
第三方控件以后升级不方便,
上司的意思!

呵呵!

讨论下一个问题吧!
另处请教一个问题:
怎样使用过程类型:
如:
type
TOperatorFun = procedure (const anode: TTreenode; ...);
//等待调用的兼容的函数
TForm1 = class(TForm)
private
FOperatorFun: TOperatorFun;

procedure F1(const anode: TTreenode; ...);
procedure F2(const anode: TTreenode; ...);
...
end;

//我在遍历树的时候,依不同的要求赋给FOperatorFun不同的函数变量,以实现不同的操作.
但是当操作的函数在 TForm类中的时候好像就不行,
而当是全局函数时就可以.
但是,如果操作函数是全局时,又要传入许多不同的参数, 很麻烦.

请问各位大xia有何高招!
 
用XTreeView吧。就一段代码而已。
下载地址:http://free.ys168.com/?crazycock 组件目录下。


unit XTreeView;

{
==============
TXTreeView 1.0 (1999-07-11)
==============

Enhaced TTreeView with 2- or 3-state checkboxes.

Freeware.

Copyright ?Roman Stedronsky 1999, Roman.Stedronsky@seznam.cz

All rights reserved. You may use this software in an application
without fee or royalty, provided this copyright notice remains intact.

types
-----
TCheckState defines 4 states for every node (No check,
Unchecked, Checked, Grayed)
public properties
-----------------
CheckStates[Index: integer] set/get the state for given node (by index)
published properties
--------------------
CheckBoxes when true, shows checkboxes
ThreeState when true, use 3-state cycle (un-checked-grayed)
when false, use 2-state cycle (unchecked-checked)
CheckBitmap defines visual appearance of checkboxes
(Width: 64 /4x16/, height: 16. See default one.)
events
------
OnStateClick occures after changing state via mouse
(Not when changing CheckStates!)
Note:
Every new node is in the state csNone by default (checkbox is not visible).
You must explicitly change it by CheckStates property. (You can also use
node's StateIndex as shown below, but why?)

StateIndex CheckState
-1 csNone
1 csUnchecked
2 csChecked
3 csGrayed
}

interface

uses
Windows, Messages, Classes, Graphics, Controls, ComCtrls, Commctrl;

type
TCheckState = (csNone, csUnchecked, csChecked, csGrayed);
TStateClickEvent = procedure(CheckState: TCheckState) of object;

TXTreeView = class(TCustomTreeView)
protected
{ internal variables }
FBitmap: TBitmap;
CheckStateImages: TImageList;
{ property variables }
FCheckBoxes: boolean;
FThreeState: boolean;
FStateClickEvent: TStateClickEvent;
{ property manipulation methods }
procedure FWriteCheckBoxes(Value: boolean);
function FReadCheckState(Index: integer): TCheckState;
procedure FWriteCheckState(Index: integer; Value: TCheckState);
procedure FWriteCheckBitmap(Value: TBitmap);
{ internal methods }
procedure ChangeCheckState(Node: TTreeNode);
procedure BitmapChanged(Sender: TObject);
public
{ overrided methods }
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
procedure CNNotify(var Message: TWMNotify); message CN_NOTIFY;
property CheckStates[Index: integer]: TCheckState read FReadCheckState write FWriteCheckState;
published
property CheckBoxes: boolean read FCheckBoxes write FWriteCheckBoxes default true;
property ThreeState: boolean read FThreeState write FThreeState default false;
property CheckBitmap: TBitmap read FBitmap write FWriteCheckBitmap stored true default nil;
property OnStateClick: TStateClickEvent read FStateClickEvent write FStateClickEvent;
published
{ make TCustomTreeView propeties published (exclude StateImages) }
property Align;
property Anchors;
property AutoExpand;
property BiDiMode;
property BorderStyle;
property BorderWidth;
property ChangeDelay;
property Color;
property Ctl3D;
property Constraints;
property DragKind;
property DragCursor;
property DragMode;
property Enabled;
property Font;
property HideSelection;
property HotTrack;
property Images;
property Indent;
property Items;
property ParentBiDiMode;
property ParentColor default False;
property ParentCtl3D;
property ParentFont;
property ParentShowHint;
property PopupMenu;
property ReadOnly;
property RightClickSelect;
property RowSelect;
property ShowButtons;
property ShowHint;
property ShowLines;
property ShowRoot;
property SortType;
property TabOrder;
property TabStop default True;
property ToolTips;
property Visible;
property OnChange;
property OnChanging;
property OnClick;
property OnCollapsing;
property OnCollapsed;
property OnCompare;
property OnCustomDraw;
property OnCustomDrawItem;
property OnDblClick;
property OnDeletion;
property OnDragDrop;
property OnDragOver;
property OnEdited;
property OnEditing;
property OnEndDock;
property OnEndDrag;
property OnEnter;
property OnExit;
property OnExpanding;
property OnExpanded;
property OnGetImageIndex;
property OnGetSelectedIndex;
property OnKeyDown;
property OnKeyPress;
property OnKeyUp;
property OnMouseDown;
property OnMouseMove;
property OnMouseUp;
property OnStartDock;
property OnStartDrag;
end;

procedure Register;

implementation

{$R XTreeView.res}

const
cCheckStatesBitmap = 'CheckStatesBitmap';

procedure Register;
begin
RegisterComponents('Extra', [TXTreeView]);
end;

{ property manipulation methods }

procedure TXTreeView.FWriteCheckBoxes(Value: boolean);
begin
FCheckBoxes := Value;
if FCheckBoxes then
StateImages := CheckStateImages
else
StateImages := nil;
end;

function TXTreeView.FReadCheckState(Index: integer): TCheckState;
begin
if (Index > -1) and (Index < Items.Count) then
if Items[Index].StateIndex = -1 then
Result := csNone
else
Result := TCheckState(Items[Index].StateIndex)
else
Result := csNone;
end;

procedure TXTreeView.FWriteCheckState(Index: integer; Value: TCheckState);
begin
if (Index > -1) and (Index < Items.Count) then
if Value = csNone then
Items[Index].StateIndex := -1
else
Items[Index].StateIndex := integer(Value);
end;

procedure TXTreeView.FWriteCheckBitmap(Value: TBitmap);
begin
if Value = nil then
begin
FBitmap.Handle := LoadBitmap(HInstance, cCheckStatesBitmap)
end
else
FBitmap.Assign(Value);
CheckStateImages.Clear; // Does Clear free memory or not?
CheckStateImages.Add(FBitmap, nil);
end;

{ internal methods }

procedure TXTreeView.BitmapChanged(Sender: TObject);
begin
CheckStateImages.Clear;
CheckStateImages.Add(FBitmap, nil);
end;

procedure TXTreeView.ChangeCheckState(Node: TTreeNode);
begin
if CheckStates[Node.AbsoluteIndex] = csUnchecked then
CheckStates[Node.AbsoluteIndex] := csChecked
else if CheckStates[Node.AbsoluteIndex] = csChecked then
begin
if FThreeState then
CheckStates[Node.AbsoluteIndex] := csGrayed
else
CheckStates[Node.AbsoluteIndex] := csUnchecked
end
else
CheckStates[Node.AbsoluteIndex] := csUnchecked;
end;

{ overrided methods }

constructor TXTreeView.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
CheckStateImages := TImageList.Create(Self);
FBitmap := TBitmap.Create;
FBitmap.OnChange := BitmapChanged;
FBitmap.Handle := LoadBitmap(HInstance, cCheckStatesBitmap);
StateImages := CheckStateImages;
FThreeState := false;
CheckBoxes := true;
ParentColor := False;
TabStop := True;
end;

destructor TXTreeView.Destroy;
begin
FBitmap.Free;
CheckStateImages.Free;
inherited Destroy;
end;

procedure TXTreeView.CNNotify(var Message: TWMNotify);
var
Node: TTreeNode;
Point: TPoint;
Position: DWORD;
begin
case message.nmhdr.code of
NM_CLICK:
begin
Position := GetMessagePos;
Point.x := LoWord(Position);
Point.y := HiWord(Position);
Point := ScreenToClient(Point);
Node := GetNodeAt(Point.x, Point.y);
if (Node <> nil) then
begin
if htOnStateIcon in GetHitTestInfoAt(Point.x, Point.y) then
begin
ChangeCheckState(Node);
if Assigned(FStateClickEvent) then
FStateClickEvent(CheckStates[Node.AbsoluteIndex]);
end;
end;
end;
end;
inherited;
end;

end.
 
OK!谢谢各位
 
看一下事件的声名吧
  type
TOperatorFun = procedure (const anode: TTreenode; ...) of object;
这样声名在类里就可以用了吧。
 

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