The default color of the Tpanel is stored in DFM, the color of the brush is set in the paint function after reading, and then the entire background is filled

The statement reads as follows:

Tcustompanel =class(Tcustomcontrol)PrivateFfullrepaint:boolean;    Fparentbackgroundset:boolean; procedureCmctl3dchanged (varMessage:tmessage);messagecm_ctl3dchanged; protected    procedureCreateParams (varParams:tcreateparams);Override; procedurePaint;Override; Property color default clbtnface;//Set default color, if not change its color, not stored in DFM PropertyFullrepaint:booleanReadFfullrepaintWriteFfullrepaintdefaultTrue;  PropertyParentcolordefaultFalse; procedureSetparentbackground (Value:boolean);Override;  Public     PropertyParentbackgroundstoredFparentbackgroundset; Constructor Create(aowner:tcomponent);Override; functionGetcontrolsalignment:talignment;Override; End;

When you place a tpanel on a form, you have:

  Object Panel1:tpanel      $      232193153'              Panel1'2      End

The equivalent of this time the color default is Clbtnface. If I change its color in the design period, it will be stored as:

  Object Panel1:tpanel      $      232193153'              Panel1'    Color =   clyellow    2  End

Finally, take a look at its paint function:

procedureTcustompanel.paint;Constalignments:Array[Talignment] ofLongint =(Dt_left, Dt_right, dt_center);varRect:trect;  Topcolor, Bottomcolor:tcolor;  Fontheight:integer;  Flags:longint; procedureadjustcolors (Bevel:tpanelbevel); beginTopcolor:=Clbtnhighlight; ifBevel = bvlowered ThenTopcolor: =Clbtnshadow; Bottomcolor:=Clbtnshadow; ifBevel = bvlowered ThenBottomcolor: =Clbtnhighlight; End;beginRect:=GetClientRect; ifBevelouter <> Bvnone Then  beginadjustcolors (Bevelouter);  Frame3d (Canvas, Rect, Topcolor, Bottomcolor, bevelwidth); End;  Frame3d (Canvas, Rect, color, color, BorderWidth); ifBevelinner <> Bvnone Then  beginadjustcolors (Bevelinner);  Frame3d (Canvas, Rect, Topcolor, Bottomcolor, bevelwidth); End;  withCanvas Do  begin    if  notThemeservices.themesenabledor  notParentbackground Then    beginBrush.color: = color;//This is where the brush is set.    If it is changed to clred, the spot will make the Tpanel into Red FillRect (Rect); End; Brush.style:=bsclear; Font:=Self.font; Fontheight:= TextHeight ('W');  withRect Do    beginTop:= ((Bottom + Top)-fontheight)Div 2; Bottom:= Top +Fontheight; End; Flags:= Dt_expandtabsorDt_vcenterorAlignments[falignment]; Flags:=drawtextbidimodeflags (Flags); DrawText (Handle, PChar (Caption),-1, Rect, Flags); End;End;

The default color of the Tpanel is stored in DFM, the color of the brush is set in the paint function after reading, and then the entire background is filled