Drag and Drop в TTreeView

Code:

unit Unit1;

interface

uses

Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

ComCtrls;

type

TForm1 = class(TForm)

   TreeView1: TTreeView;

   procedure TreeView1DragDrop(Sender, Source: TObject; X, Y: Integer);

   procedure TreeView1DragOver(Sender, Source: TObject; X, Y: Integer;

     State: TDragState; var Accept: Boolean);

private

   procedure MoveNode(TargetNode, SourceNode: TTreeNode);

end;

var

Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.MoveNode(TargetNode, SourceNode: TTreeNode);

var

NodeTmp: TTreeNode;

I: Integer;

begin

with TreeView1 do

begin

   // проверяем, является ли целевой элемент предком перетаскиваемого

   NodeTmp := TargetNode.Parent;

   while Assigned(NodeTmp) do

     if NodeTmp = SourceNode then

       Abort

     else

       NodeTmp := NodeTmp.Parent;

   // копируем перетаскиваемый элемент в новосозданный

   NodeTmp := Items.AddChild(TargetNode, SourceNode.Text);

   NodeTmp.Data := SourceNode.Data;

   for I := 0 to SourceNode.Count - 1 do

     MoveNode(NodeTmp, SourceNode.Item[I]);

   Selected := NodeTmp;

   TopItem := NodeTmp.getPrev;

   TargetNode.Expand(True);

end;

end;

procedure TForm1.TreeView1DragDrop(Sender, Source: TObject; X, Y: Integer);

var

TargetNode, SourceNode: TTreeNode;

begin

with TreeView1 do

begin

   TargetNode := GetNodeAt(X, Y);

   SourceNode := Selected;

   if (TargetNode = SourceNode) or (TargetNode = nil) then

   begin

     EndDrag(False);

     Exit;

   end;

   MoveNode(TargetNode, SourceNode);

   SourceNode.Free;

end;

end;

procedure TForm1.TreeView1DragOver(Sender, Source: TObject; X, Y: Integer;

State: TDragState; var Accept: Boolean);

var

SourceNode, TargetNode, NodeTmp: TTreeNode;

begin

if Sender = TreeView1 then

try

   // скроллинг дерева при перетаскивании

   if Y > TreeView1.Height - 10 then

   begin

     TreeView1.TopItem := TreeView1.TopItem.getNext;

     Sleep(100); // пауза

   end else

     if Y < 10 then

     begin

       TreeView1.TopItem := TreeView1.TopItem.getPrev;

       Sleep(100); // пауза

     end;

   TargetNode := TreeView1.GetNodeAt(X, Y);

   SourceNode := TreeView1.Selected;

   if (TargetNode = nil) or (TargetNode = SourceNode) then Abort;

   Accept := True;

   // проверяем, является ли целевой элемент предком перетаскиваемого

   NodeTmp := TargetNode.Parent;

   while Assigned(NodeTmp) do

     if NodeTmp = SourceNode then

       Abort

     else

       NodeTmp := NodeTmp.Parent;

except

   Accept := False;

end;

end;

end.

Code:

unit Unit1;

interface

uses

  Windows, Messages, SysUtils, Variants, Classes, Controls, Forms,

  Dialogs, StdCtrls, ComCtrls;

type

  TForm1 = class(TForm)

    TreeView1: TTreeView;

    Label1: TLabel;

    procedure TreeView1DragDrop(Sender, Source: TObject; X, Y: Integer);

    procedure TreeView1DragOver(Sender, Source: TObject; X, Y: Integer;

      State: TDragState; var Accept: Boolean);

  private

    { Private declarations }

    Procedure MoveNode(TargetNode, SourceNode : TTreeNode);

  public

    { Public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

//

// Procedure which will move node and its subnodes

//

Procedure TForm1.MoveNode(TargetNode, SourceNode : TTreeNode);

var

  nodeTmp : TTreeNode;

  i : Integer;

begin

  with TreeView1 do

  begin

    nodeTmp := Items.AddChild(TargetNode,SourceNode.Text);

    for i := 0 to SourceNode.Count -1 do

    begin

      MoveNode(nodeTmp,SourceNode.Item[i]);

    end;

  end;

end;

procedure TForm1.TreeView1DragDrop(Sender, Source: TObject; X, Y: Integer);

var

  TargetNode, SourceNode : TTreeNode;

begin

  with TreeView1 do

  begin

    TargetNode := GetNodeAt(X,Y); // Get target node

   SourceNode := Selected;

    if (TargetNode = nil) then

    begin

      EndDrag(False);

      Exit;

    end;

    MoveNode(TargetNode,SourceNode);

    SourceNode.Free;

  end;

end;

procedure TForm1.TreeView1DragOver(Sender, Source: TObject; X, Y: Integer;

  State: TDragState; var Accept: Boolean);

begin

  if (Sender = TreeView1) then // If TRUE than accept the draged item

begin

    Accept := True;

  end;

end;

end.