listbox多选状态下的自拖与互拖

unit Unit1;

file://yanlei:E_mail [email protected]

interface

uses

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

    Dialogs, StdCtrls;

type

    TForm1 = class(TForm)

        ListBox1: TListBox;

        ListBox2: TListBox;

        procedure ListBox1DragDrop(Sender, Source: TObject; X, Y: Integer);

        procedure ListBox1DragOver(Sender, Source: TObject; X, Y: Integer;

            State: TDragState; var Accept: Boolean);

        procedure FormCreate(Sender: TObject);

    private

    { Private declarations }

    public

    { Public declarations }

    end;

var

    Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.ListBox1DragOver(Sender, Source: TObject; X, Y: Integer;

    State: TDragState; var Accept: Boolean);

var

    aPoint: TPoint;

begin

    aPoint.x := x;

    aPoint.y := y;

    if (source is Tlistbox) then

        if ((source as Tlistbox).SelCount > 0) and

            ((sender as Tlistbox).ItemAtPos(apoint, true) <> -1)

            and ((sender as Tlistbox).itematpos(apoint, true) <> (sender as Tlistbox).itemindex) then

        begin

            accept := true;

        end;

end;

procedure TForm1.ListBox1DragDrop(Sender, Source: TObject; X, Y: Integer);

var

    aPoint: TPoint;

    st: string;

    p: integer;

    i, num: integer;

    MYlBox: TStrings;

begin

    aPoint.x := x;

    aPoint.y := y;

    p := (sender as Tlistbox).itematpos(aPoint, true);

    MYlBox := Tstringlist.Create;

    try

        Num := (source as Tlistbox).Items.Count;

        for i := num - 1 downto 0 do

        begin

            if (source as Tlistbox).Selected[i] then

            begin

                st := (source as Tlistbox).Items[i];

                MYlBox.Add(st)

            end;

        end;

        if p > -1 then

        begin

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

            begin

                (sender as Tlistbox).Items.Insert(p, mylbox[i])

            end;

        end

        else

        begin

            for i := Mylbox.Count - 1 downto 0 do

            begin

                (sender as Tlistbox).Items.Add(mylbox[i])

            end;

        end;

        (source as Tlistbox).DeleteSelected;

        if P > -1 then

            (sender as Tlistbox).Selected[p] := true;

    finally

        mylbox.Free;

    end;

end;

procedure TForm1.FormCreate(Sender: TObject);

begin

    listbox2.OnDragDrop := listbox1.OnDragDrop;

    listbox2.OnDragOver := listbox1.OnDragOver;

    listbox1.MultiSelect := true;

    listbox2.MultiSelect := true;

    listbox1.DragMode := dmAutomatic;

    listbox2.DragMode := dmAutomatic;

end;

end.