递归法选取树子节点 控件拖放

递归法选取树子节点 控件拖放

适合N层树，通用

unit treeRecursion;
{
标题: 递归法选取树子节点 控件拖放
作者: vigor
时间: 2004.3.26
}
interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Buttons, StdCtrls, ComCtrls, ExtCtrls;

type
TForm1 = class(TForm)
TreeView1: TTreeView;
ListBox1: TListBox;
Splitter1: TSplitter;
procedure TreeView1MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
procedure ListBox1DragOver(Sender, Source: TObject; X, Y: Integer;
State: TDragState; var Accept: Boolean);
procedure ListBox1DragDrop(Sender, Source: TObject; X, Y: Integer);
private
{ Private declarations }
public
{ Public declarations }
procedure AddSelectedChildrenToListbox(tree : TTreeView;startNode :TTreeNode;listBox :TListBox);
end;

var
Form1: TForm1;
g_startNode : TTreeNode;

implementation

{$R *.dfm}
{
拖放控件
准备条件:
源控件 DragKind :=dkDrag; DragCursor :=crDefalt; DragMode := dmManual;
目标控件
实施步骤:
1. 开始拖动操作 onMouseDown BeginDrag ( 源控件 )
　　 2. 接收拖动项目 OnDragOver (目标控件)
　　 3. 放下拖动项目 OnDragDrop (目标控件)
　　 4. 终止拖动操作 OnEndDrag　 ( 源控件 )
}

procedure TForm1.AddSelectedChildrenToListbox(tree: TTreeView;
startNode: TTreeNode; listBox: TListBox);
var
curParent : TTreeNode;
begin
if not(tree.Selected.HasChildren) then
begin
if listBox.Items.IndexOf(Trim(tree.Selected.Text)) = -1 then
listBox.Items.Add(Trim(tree.Selected.Text));
end
else
begin
tree.Selected := tree.Selected.GetNext;
while tree.Selected<>nil do
begin
curParent := tree.Selected;//保护现场^^
AddSelectedChildrenToListbox(tree,tree.Selected,listBox);
tree.Selected := curParent.getNextSibling;//恢复现场^^
end;
end;
end;

procedure TForm1.TreeView1MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
if Button = mbLeft then
begin
g_startNode := TreeView1.GetNodeAt(X,Y);
if Assigned(g_startNode) then
TreeView1.BeginDrag(True);
end;
end;

procedure TForm1.ListBox1DragOver(Sender, Source: TObject; X, Y: Integer;
State: TDragState; var Accept: Boolean);
begin
if Source = TreeView1 then
Accept := True;
end;
procedure TForm1.ListBox1DragDrop(Sender, Source: TObject; X, Y: Integer);
begin
if Source = TreeView1 then
begin
AddSelectedChildrenToListbox(treeview1,g_startNode,listbox1);
end;
end;

end.

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