> { Look up the run-time info for the property named Color. }
> PropInfo := GetPropInfo(Components[I].ClassInfo, 'Color');
> if PropInfo <> nil then
> { Set the Color property. }
> SetOrdProp(Components[I], PropInfo, Color);
> end;
That will work properly only if 'Color' is a property of type TColor
(although admittedly it's likely to be). Here's a function we use:
procedure SetOrdinalProperty(Object: TObject; PropertyName: string;
PropType: TypeInfo; PropValue: LongInt);
var PropInfo: PPropInfo;
begin
PropInfo := TypInfo.GetPropInfo(Object.ClassInfo, PropertyName);
if (PropInfo <> nil) and (PropInfo^.PropType^ = PropType) then begin
SetOrdProp(Object, PropInfo, PropValue);
end;
end;
Then we can call it for any ordinal property. The call to set the
'Color' property of a component to clWindow, only if it has such a
property and the property is of type TColor, would be as follows:
SetOrdinalProperty(Components[i], 'Color', System.TypeInfo(TColor),
clWindow);
Cheers,
Carl Reynolds Ph: +64-9-4154790
CJN Technologies Ltd. Fax: +64-9-4154791
[EMAIL PROTECTED] DDI: +64-9-4154795
PO Box 302-278, North Harbour, Auckland, New Zealand
12 Piermark Drive, North Harbour Estate, Auckland, NZ
Visit our website at http://www.cjntech.co.nz/
-----Original Message-----
From: Kieron Lawson [SMTP:[EMAIL PROTECTED]]
Sent: Wednesday, October 13, 1999 10:03 PM
To: Multiple recipients of list delphi
Subject: Re: [DUG]: Changing control style
Wednesday, October 13, 1999, 9:43:10 PM, you wrote:
> I have a panel which has a number of controls (dbedits, dbcheckbox,
etc) and
> I want to change the background colour of each control when the Insert
> button is clicked. I've tried using the Controls property like so:
> for x := 0 to Panel5.ControlCount - 1 do
> begin
> MyControl := Panel5.Controls[x];
> MyControl.Color := clRed;
> end;
> but Color is a protected property of TControl. Is there any other way
of
> doing this without hard-coding each individual control. I also want to
> change the colour back when the new record is posted.
Hi Laurence,
If you have Secrets of Delphi 2 this is the first subject dealt with
in chapter 7.
If you don't, here's the code example:
procedure TForm1.ChangeColorsTo(Color: TColor);
var
I: Integer;
PropInfo: PPropInfo;
begin
{ Look up each component on the form. }
for I := 0 to ComponentCount-1 do
begin
{ Look up the run-time info for the property named Color. }
PropInfo := GetPropInfo(Components[I].ClassInfo, 'Color');
if PropInfo <> nil then
{ Set the Color property. }
SetOrdProp(Components[I], PropInfo, Color);
end;
{ Finally, change the color of the form itself. }
PropInfo := GetPropInfo(ClassInfo, 'Color');
SetOrdProp(Self, PropInfo, Color);
end;
It relies on the fact that Color is a published property and
therefore has run-time type information available.
As mentioned previously on this list, this is a book well worth owning,
although I understand that there is an updated Delphi 5 version in the
works.
Kieron.
------------------------------------------------------------------------
---
New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED]
Website: http://www.delphi.org.nz
application/ms-tnef
