在delphi中，在运行时如何让拖动的控件显示在最上方？

我也最近才实现了这个功能，可以说是MPI窗口！
用PageControl控件可以实现，你把窗体的边框设为无边框，打开的时候最大化，每打开一个窗体就在主窗体的PageControl上面新建一个标签页，标签显示窗体的Caption属性，并把窗体的父控件设标签页，再在PageControl的标签双击事件中写入双击可以关闭当前标签页的事件就可以了！

(Sender as TPanel).BringToFront;

unit Unit1;

interface

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

type
TForm1 = class(TForm)
Panel1: TPanel;
Panel2: TPanel;
Panel3: TPanel;
RadioButton1: TRadioButton;
RadioButton2: TRadioButton;
procedure Panel1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
RadioButton1.Caption := '置前';
RadioButton2.Caption := '置后';
RadioButton1.Checked := True;
Panel2.OnClick := Panel1Click;
Panel3.OnClick := Panel1Click;

Panel1.ParentBackground := False;
Panel1.Color := clRed;
Panel2.ParentBackground := False;
Panel2.Color := clLime;
Panel3.ParentBackground := False;
Panel3.Color := clBlue;
end;

procedure TForm1.Panel1Click(Sender: TObject);
begin
if RadioButton1.Checked then TPanel(Sender).BringToFront;
if RadioButton2.Checked then TPanel(Sender).SendToBack;
end;

end.
--------------------------------------------------------------------------------
窗体文件:
--------------------------------------------------------------------------------

object Form1: TForm1
Left = 0
Top = 0
Caption = 'Form1'
ClientHeight = 174
ClientWidth = 264
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
OnCreate = FormCreate
PixelsPerInch = 96
TextHeight = 13
object Panel1: TPanel
Left = 8
Top = 16
Width = 151
Height = 41
Caption = 'Panel1'
TabOrder = 0
OnClick = Panel1Click
end
object Panel2: TPanel
Left = 46
Top = 40
Width = 151
Height = 41
Caption = 'Panel2'
TabOrder = 1
end
object Panel3: TPanel
Left = 102
Top = 63
Width = 151
Height = 41
Caption = 'Panel3'
TabOrder = 2
end
object RadioButton1: TRadioButton
Left = 32
Top = 136
Width = 113
Height = 17
Caption = 'RadioButton1'
TabOrder = 3
end
object RadioButton2: TRadioButton
Left = 151
Top = 136
Width = 113
Height = 17
Caption = 'RadioButton2'
TabOrder = 4
end
end

去看下万一博客吧.
有这样的一个实类!