Lazarus

Miscellaneous => Suggestions => LCL => Topic started by: pcurtis on October 21, 2021, 07:03:51 pm

Title: [SOLVED] Component inheritance
Post by: pcurtis on October 21, 2021, 07:03:51 pm

How can I test if a component is derived from TControl or is a visual component?

Title: Re: Component inheritance
Post by: devEric69 on October 21, 2021, 07:12:15 pm

Hello,

Already 2 simple ways (having said that, I thought that the proper of a control, was to be visual, but well... I don't see where the trap is). So, here is my dummy:

Code: Pascal  [Select][+][-]

1. if (oMyComponent is TControl) then
2. ...\...
3. else if (oMyComponent is TWinControl) then
4. ...\...

or

Code: Pascal  [Select][+][-]

1. if (oMyComponent.InheritsFrom(TControl)) then
2. ...\...
3. else if (oMyComponent.InheritsFrom(TWinControl)) then
4. ...\...

Title: Re: Component inheritance
Post by: pcurtis on October 21, 2021, 07:17:27 pm

Thanks

Title: Re: [SOLVED] Component inheritance
Post by: howardpc on October 21, 2021, 09:10:28 pm

In fact the simple test

Code: Pascal  [Select][+][-]

1. if oMyComponent.InheritsFrom(TControl) then ...

is sufficient.
TWinControl is a TControl descendant.