I am sure this is a dumb ?, but I want a subroutine that will change all
of the components of a form to Enabled := False.

How do I do this?

I am sure this is a dumb ?, but I want a subroutine that will change all of the components of a form to Enabled := False. How do I do this?

This code disables all components owned by form:

for i := 0 to form.Components.Count - 1 do
   form.Components[i].Enabled := False;

Untested, eventually Components.Count has to be replaced by ComponentCount.

DoDi

I am sure this is a dumb ?, but I want a subroutine that will change all of the components of a form to Enabled := False. How do I do this?

for i:=0 to ControlCount-1 do
  Controls[i].Enabled:=false;

Mattias

2013/7/31 Hans-Peter Diettrich

Previous answers made me wonder: are you sure you meant "Component", not "Control"? If the form contains non-visual components, this could change the result.

TComponent does not have Enabled. So the above code does not work. TControl has Enabled.
Disabling a control (e.g. no focus, some widgetsets draw them gray) automatically disables child controls. So the easiest way to disable all controls on a form is to set Form1.Enabled:=false.

Mattias

Mattias

Terry A. Haimann wrote

I am sure this is a dumb ?, but I want a subroutine that will change all of the components of a form to Enabled := False.

Not sure if you wanted controls to be "disabled" or "readonly" (when possible)...

If you wanted the latter, then tiOPF has a component TtiReadOnly that you can drop on a form and simply set ReadOnly = True at runtime, and all is done for you. The TtiReadOnly component also has a few events that you can hook into so you can have more fine grained control over what controls or forms get processed.

http://sourceforge.net/p/tiopf/code/ci/tiopf2/tree/GUI/tiReadOnly.pas

This unit is completely stand-alone and doesn't use any other tiOPF units or code.

Regards,
- Graeme -

Hi Mattias

What happens afterwards when I say Form1.Enabled:=true; ? If some controls were enabled beforehand and some were disabled, will this be remembered or will I need to enable them one-by-one or will all controls be enabled by default?

Cheers
Chavoux
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Interesting and I didn't know you could do that. But, more of what I have in mind is.

I have a bunch of database components on a form, I want them to be enabled only after hitting the edit or insert button on the DbNavigator. Since this is going to occur in multiple points in my button procedure, it would be programmatically better if this could be done in a sub procedure. Also, I have fields that are dependent on other fields, so fieldsz only would become active if fieldx has a 'Y' in it.

2013/7/31 Terry A. Haimann

Hmm, I am still unsure, are you really speaking of components (in which case you may want to do things like connect conditionally) or of controls (you want only to prevent the user from interacting with the form)?

Components[] contains the components *owned* by the form, while Controls[] contains only the top-level controls, whose *Parent* is the form.

DoDi

Thanks, I missed that.

Enabling/disabling a Parent does not change the Enabled *values* of its child controls. Child controls of a disabled Parent are disabled implicitly, by e.g. message processing logic.

DoDi

I am talking mostly about TDBEdit and a few TDBComboBox objects.

[...] > Just a related question on this: What happens afterwards when I say Form1.Enabled:=true; ?

Form1.Enabled does not change the 'Enabled' values of child controls. A control is enabled if itself and all its parents are enabled. See TControl.IsEnabled.

If some controls were enabled beforehand and some were disabled, will this be remembered or will I need to enable them one-by-one or will all controls be enabled by default?

You get the old state. No child property was changed.

Mattias

What is the question?

Mattias

2013/7/31 Hans-Peter Diettrich

OK, but since Components can be Controls or not, they could have an Enabled property or not. So shouldn't the loop actually be something like:

for i := 0 to form.Components.Count - 1 do
    if form.Components[i] is TControl
        then form.Components[i].Enabled := False;

           then TControl(form.Components[i]).Enabled := False;

DoDi

2013/7/31 Hans-Peter Diettrich

Yes, I saw I missed that one later :-P