BringToFront、SendToBack - 控件置前与置后

本例效果图:

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代码文件:

---

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