不好意思請問各位前輩,
小弟在程式設計的過程中,覺得delphi所提供的元件,
有些如果能稍做修改,會更好用,但不知如何下手,

舉例來說,我希望能夠修改以Tpanel為基礎的元件,
讓滑鼠點到該Panel時,可以於框線加上不同顏色,如紅色,失焦時則框線顏色消失,
而在該panel按滑鼠右鍵時,能在該座標上popup出popupmenu來,

請問上述該如何實作呢? 有辦法做到嗎? 請各位前輩提供個方向,有範例就更好,
自訂元件的設計網路上有看了一些網站,但還是一知半解,
是否有修改視覺化元件資訊較完整的網站呢?

先謝謝前輩的幫忙了.

//開啟一個Package專案檔
//加入下面的MyPanel.pas
//Compilier後 install
//就可以使用了
//Popupmenu的功能我沒測試

unit MyPanel;
interface
uses
SysUtils, Classes, Controls, Windows, Graphics, Menus, ExtCtrls, Messages;
type
TMyPanel = class(TPanel)
private
{ Private declarations }
procedure MyPaint(IsPaint :Boolean);
protected
{ Protected declarations }
procedure DoEnter; override;
procedure DoExit; override;
procedure Paint;override;
procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
public
{ Public declarations }
constructor Create(AOwner : TComponent);override;
destructor Destroy;override;
published
{ Published declarations }
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Samples', [TMyPanel]);
end;
{ TMyPanel }
constructor TMyPanel.Create(AOwner: TComponent);
begin
inherited;
//Self.TabStop := True;
end;
destructor TMyPanel.destroy;
begin

inherited;
end;
procedure TMyPanel.DoEnter;
begin
inherited;
MyPaint(True);
//Self.Repaint;
end;
procedure TMyPanel.DoExit;
begin
inherited;
MyPaint(False);
end;
procedure TMyPanel.MouseDown(Button: TMouseButton; Shift: TShiftState; X,
Y: Integer);
begin
inherited;
if Self.Focused then
begin
if (Button = mbRight) then
begin
if Assigned(Self.PopupMenu) then
Self.PopupMenu.Popup(X,Y);
end
else
begin
if Assigned(Self.PopupMenu) then
Self.PopupMenu.Popup(-100,-100);
end;
end;
MyPaint(True);
end;

procedure TMyPanel.MyPaint(IsPaint: Boolean);
begin
if IsPaint then
begin
Self.Canvas.Pen.Color := clRed;
Self.Canvas.Pen.Width := 3;
//Canvas.Brush.Style := bsClear;
Self.Canvas.MoveTo(0,0);
Self.Canvas.LineTo(0,Self.Height);
Self.Canvas.MoveTo(0,Self.Height);
Self.Canvas.LineTo(Self.Width,Self.Height);
Self.Canvas.MoveTo(Self.Width,Self.Height);
Self.Canvas.LineTo(Self.Width,0);
Self.Canvas.MoveTo(Self.Width,0);
Self.Canvas.LineTo(0,0);
end
else
begin
Self.Canvas.Pen.Color := Color;
Self.Canvas.Pen.Width := 3;
//Canvas.Brush.Style := bsClear;
Self.Canvas.MoveTo(0,0);
Self.Canvas.LineTo(0,Self.Height);
Self.Canvas.MoveTo(0,Self.Height);
Self.Canvas.LineTo(Self.Width,Self.Height);
Self.Canvas.MoveTo(Self.Width,Self.Height);
Self.Canvas.LineTo(Self.Width,0);
Self.Canvas.MoveTo(Self.Width,0);
Self.Canvas.LineTo(0,0);
end;
end;
procedure TMyPanel.Paint;
begin
inherited;
{if Self.Focused then
begin
MyPaint(True);
end; }
end;
end.

------
何需Coding爭峰
千人指 萬人鋒
敢問Coding頂峰
三尺秋水塵不染
天下無雙

編輯記錄

1.在底下網址中下載 AlPanel v.3.69 這個元件, 含 source
http://www.torry.net/pages.php?s=79


2.TPanel 有個 PopupMenu 的屬性, 指定一個 TPopupMenu 給這個屬性即可