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DieDolly

Registriert seit: 22. Jun 2018
754 Beiträge
 
#7

AW: Anfängerfrage eigene TLabel-Komponente

  Alt 23. Jun 2018, 21:02
Weil ich ab da den Wert der Zwischenvariable nicht mehr brauche.
Ich habe den Fehler gefunden. Im Constructor fehlte ein Minuszeichen.

Hier ist mein Zwischenresultat
Delphi-Quellcode:
unit MyLabel;

interface

uses
 Winapi.Windows, Winapi.Messages, System.SysUtils, System.Classes, Vcl.StdCtrls, Vcl.Graphics, Vcl.Controls, Dialogs;

const
 CColorDefault: TColor = clRed;
 CColorHover: TColor = clGreen;

type
 TMyLabel = class(TLabel)
 private
  {Private-Deklarationen}
  FLastLabelColor: TColor;
  FStyles: TFontStyles;

  FColorHover: TColor;
  FColorActive: TColor;

  FOnMouseEnter: TNotifyEvent;
  FOnMouseLeave: TNotifyEvent;

  FUnderlinedOnEnter: Boolean;
  FItalicOnEnter: Boolean;

  function GetLastLabelColor: TColor;
  procedure SetLastLabelColor(aLabel: TLabel);
  procedure SetLabelMouseProperties(Sender: TLabel; Color: TColor; Cursor: TCursor = crDefault; Styles: TFontStyles = []);
 protected
  {Protected-Deklarationen}
 public
  {Public-Deklarationen}
  constructor Create(AOwner: TComponent); override;

  procedure CMMouseEnter(var Message: TMessage); message CM_MOUSEENTER;
  procedure CMMouseLeave(var Message: TMessage); message CM_MOUSELEAVE;
 published
  {Published-Deklarationen}
  property ColorHover: TColor read FColorHover write FColorHover;
  property ColorActive: TColor read FColorActive write FColorActive;
  property UnderlinedOnEnter: Boolean read FUnderlinedOnEnter write FUnderlinedOnEnter;

  property ItalicOnEnter: Boolean read FItalicOnEnter write FItalicOnEnter;

  property OnMouseEnter: TNotifyEvent read FOnMouseEnter write FOnMouseEnter;
  property OnMouseLeave: TNotifyEvent read FOnMouseLeave write FOnMouseLeave;
 end;

procedure register;

implementation

// Funktionen um die letzte Farbe eines Labels vor dem MouseMove-Event zwischenzuspeichern und wieder auszulesen
function TMyLabel.GetLastLabelColor: TColor;
begin
 Result := FLastLabelColor;
 FLastLabelColor := -1;
end;

procedure TMyLabel.SetLastLabelColor(aLabel: TLabel);
begin
 if FLastLabelColor = -1 then
  FLastLabelColor := aLabel.Font.Color;
end;

procedure TMyLabel.SetLabelMouseProperties(Sender: TLabel; Color: TColor; Cursor: TCursor = crDefault; Styles: TFontStyles = []);
begin
 TLabel(Sender).Font.Color := Color;
 TLabel(Sender).Cursor := Cursor;
 TLabel(Sender).Font.Style := Styles;
end;

//

constructor TMyLabel.Create(AOwner: TComponent);
begin
 inherited Create(AOwner);

 FLastLabelColor := -1;

 Color := CColorDefault;
 Font.Color := CColorDefault;

 ColorHover := CColorHover;
 ColorActive := CColorHover;
end;

procedure TMyLabel.CMMouseEnter(var Message: TMessage);
begin
 inherited;

 FStyles := [];
 if FUnderlinedOnEnter then
  FStyles := FStyles + [fsUnderline];
 if FItalicOnEnter then
  FStyles := FStyles + [fsItalic];

 SetLastLabelColor(Self);
 SetLabelMouseProperties(Self, CColorHover, crHandPoint, FStyles);

 if Assigned(FOnMouseEnter) then
  FOnMouseEnter(Self);
end;

procedure TMyLabel.CMMouseLeave(var Message: TMessage);
begin
 inherited;

 SetLabelMouseProperties(Self, GetLastLabelColor);

 if Assigned(FOnMouseLeave) then
  FOnMouseLeave(Self);
end;

procedure register;
begin
 RegisterComponents('My Label', [TMyLabel]);
end;

end.

Geändert von DieDolly (23. Jun 2018 um 21:09 Uhr)
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