ListBox1相互拖拽数据Demo

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ShellApi;

type
  TForm1 = class(TForm)
    ListBox1: TListBox;
    DropFileListBox1: TListBox;
    Label1: TLabel;
    Label2: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure ListBox1Click(Sender: TObject);
    procedure ListBox1DblClick(Sender: TObject);
    procedure DropFileListBox1Click(Sender: TObject);
    procedure DropFileListBox1DblClick(Sender: TObject);
    procedure ListBox1DragOver(Sender, Source: TObject; X, Y: Integer;
      State: TDragState; var Accept: Boolean);
    procedure ListBox1DragDrop(Sender, Source: TObject; X, Y: Integer);



  private
    procedure WMDROPFILES(var Msg: TMessage);
    procedure DropFileListBox1DropFiles(Sender: TObject;
      FileNames: TStringList);

    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  S: AnsiString;

implementation

{$R *.dfm}

procedure TForm1.WMDROPFILES(var Msg: TMessage);
var
  a : Integer;
  Buffer: Array[0..255] of Char;
begin
  a := DragQueryFile(Msg.wParam, $FFFFFFFF, Buffer, 255);
  for a := 0 to a - 1 do begin    // 处理选择多个文件
     DragQueryFile(Msg.wParam, a, Buffer, 255);  // 文件名就在Buffer里面了
     ListBox1.Items.Append(buffer);   // 将文件名称添加到ListBox1的最后
  end;
  DragFinish(Msg.wParam);
end;




procedure TForm1.FormCreate(Sender: TObject);
begin
  DragAcceptFiles(Handle, True);
  DropFileListBox1.OnDragDrop := listbox1.OnDragDrop;
  DropFileListBox1.OnDragOver := listbox1.OnDragOver;
  DropFileListBox1.MultiSelect := True;
  ListBox1.MultiSelect := True;
  DropFileListBox1.DragMode := dmAutomatic;
  ListBox1.DragMode := dmAutomatic;

end;

procedure TForm1.ListBox1Click(Sender: TObject);
begin
  S := ListBox1.Items.Strings[ListBox1.ItemIndex];   // 取文件路径及名称
end;

procedure TForm1.ListBox1DblClick(Sender: TObject);
begin
  ShellExecute(handle,'Open',PChar(S),nil,nil,SW_SHOWNORMAL);  // 打开文件
end;

procedure TForm1.DropFileListBox1DropFiles(Sender: TObject;
  FileNames: TStringList);
begin
 DropFileListBox1.Items.AddStrings(FileNames);  // 处理文件拖拽
end;

procedure TForm1.DropFileListBox1Click(Sender: TObject);
begin
  S := DropFileListBox1.Items.Strings[DropFileListBox1.ItemIndex];
end;

procedure TForm1.DropFileListBox1DblClick(Sender: TObject);
begin
  ShellExecute(handle,'Open',PChar(S),nil,nil,SW_SHOWNORMAL);  // 打开文件
end;
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;

end.