TPanel: what changed
Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.
Title: TPanel
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| 1 | + | **TPanel**  is a component that creates a panel on a form. A TPanel is a descendant of [[TWinControl]] and is available under the [[Standard tab]] of the [[Component Palette]]. A TPanel can act as a visible container for other components. | |
| 2 | + | ||
| 3 | + | ## Example | |
| 4 | + | ||
| 5 | + | One way to use panels is when the control group is displayed and hidden. Instead of showing or hiding individual controls, you can hide and show the panel and all of its child controls with a single command. In this example, the following components are used: [[TButton]], [[TShape]] | |
| 6 | + | ||
| 7 | + | ### Create code | |
| 8 | + | ||
| 9 | + | - Create a new blank [[Graphical User Interface|GUI]] application with the [[TForm|form]] Form1 | |
| 10 | + | - Create the OnCreate event handler for the form, by clicking on your form, use the Object Inspector, the tab events, select the OnCreate event and click the button \[...\] or double click the button in the form. | |
| 11 | + | - Add following code (Complete the missing parts): | |
| 12 | + | ||
| 13 | + | ``` pascal | |
| 14 | + | ||
| 15 | + | unit Unit1; | |
| 16 | + | ||
| 17 | + | {$mode objfpc}{$H+} | |
| 18 | + | ||
| 19 | + | interface | |
| 20 | + | ||
| 21 | + | uses | |
| 22 | + | Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls; | |
| 23 | + | ||
| 24 | + | type | |
| 25 | + | ||
| 26 | + | { TForm1 } | |
| 27 | + | ||
| 28 | + | TForm1 = class(TForm) | |
| 29 | + | procedure FormCreate(Sender: TObject); | |
| 30 | + | private | |
| 31 | + | aPanel:TPanel; | |
| 32 | + | procedure aButtonClick(Sender: TObject); | |
| 33 | + | public | |
| 34 | + | ||
| 35 | + | end; | |
| 36 | + | ||
| 37 | + | var | |
| 38 | + | Form1: TForm1; | |
| 39 | + | ||
| 40 | + | implementation | |
| 41 | + | ||
| 42 | + | {$R *.lfm} | |
| 43 | + | ||
| 44 | + | { TForm1 } | |
| 45 | + | ||
| 46 | + | procedure TForm1.FormCreate(Sender: TObject); | |
| 47 | + | var | |
| 48 | + | aButton:TButton; | |
| 49 | + | ||
| 50 | + | aShape1,aShape2:TShape; | |
| 51 | + | begin | |
| 52 | + | Caption :='Panel demo'; | |
| 53 | + | aButton:=TButton.Create(Self); | |
| 54 | + | aButton.Parent:=Self; | |
| 55 | + | aButton.Caption:= 'Show/Hide'; | |
| 56 | + | aPanel:=TPanel.Create(Self); | |
| 57 | + | aPanel.Parent:=Self; | |
| 58 | + | aPanel.Caption:=''; | |
| 59 | + | aShape1:=TShape.Create(aPanel); | |
| 60 | + | aShape1.Parent:=aPanel; | |
| 61 | + | aShape1.Shape:=stStar; | |
| 62 | + | aShape1.Top := 5; | |
| 63 | + | aShape2:=TShape.Create(aPanel); | |
| 64 | + | aShape2.Parent:=aPanel; | |
| 65 | + | aShape2.Shape:=stStar; | |
| 66 | + | aShape2.Top := 5; | |
| 67 | + | aShape2.Left:=aShape1.Width+10; | |
| 68 | + | aPanel.Height:=aShape1.Height+10; | |
| 69 | + | aButton.Top:=aPanel.Height+10; | |
| 70 | + | aButton.OnClick:=@aButtonClick; | |
| 71 | + | Height := aButton.Top+aButton.Height+10; | |
| 72 | + | end; | |
| 73 | + | ||
| 74 | + | procedure TForm1.aButtonClick(Sender: TObject); //the event handler for the button | |
| 75 | + | begin | |
| 76 | + | if (Sender is TButton) | |
| 77 | + | then begin | |
| 78 | + | if aPanel.Visible then aPanel.Visible := false else aPanel.Visible := true; | |
| 79 | + | end; | |
| 80 | + | end; | |
| 81 | + | end. | |
| 82 | + | ``` | |
| 83 | + | ||
| 84 | + | ## See also | |
| 85 | + | ||
| 86 | + | - [[doc:lcl/extctrls/tpanel.html|TPanel doc]] | |
| 87 | + | - [[TBevel]] | |
| 88 | + | - [[TFrame]] | |
| 89 | + | - [[TFlowPanel]] | |
| 90 | + | ||
| 91 | + | --- | |
| 92 | + | *From the Free Pascal wiki, page "TPanel", as it stood on 2019-10-04 after a change by Djzepi, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).* |