listbox多選狀態下的自拖與互拖

unit Unit1;

file://yanlei:E_mail yanleiigis@21cn.com

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.