# QtRuby - Error

**URL:** <https://www.ruby-forum.com/t/qtruby-error/109640>\
**Category:** Ruby\
**Created:** [July 17, 2007, 2:47pm UTC](https://www.ruby-forum.com/t/qtruby-error/109640 "2007-07-17T14:47:13Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![GermSSSSn\_alberto\_G](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/439d5e/32.png) [@GermSSSSn\_alberto\_G](https://www.ruby-forum.com/u/GermSSSSn_alberto_G)\
**Post date:** [July 17, 2007, 2:47pm UTC](https://www.ruby-forum.com/t/qtruby-error/109640/1 "2007-07-17T14:47:13Z")

</div>

Hello,  
I new in the ruby world.  
Sorry my english, i’m argentino and speak spanish.

My question is about QtRuby. Where can tutorials, Faq, Qt’s Classes?.  
Qt4 work with ruby or only Qt3?  
I’ design form with Qt4-designer and:

rbuic mainWindow.ui \> mainWindow.rb

##################################################################  
ggerman@comandante:~/Qt4/example$ cat mainWindow.rb

# Form implementation generated from reading ui file ‘mainWindow.ui’

# 

# Created: mar jul 17 08:28:32 2007

# by: The QtRuby U. Interface Compiler (rbuic)

# 

# WARNING! All changes made in this file will be lost!

require ‘Qt’  
class MainWindow \< Qt::MainWindow  
def initialize(parent = nil, name = nil, fl = WType\_TopLevel)  
super  
statusBar()  
setCentralWidget(Qt::Widget.new(self, “qt\_central\_widget”))  
@Widget = Qt::Widget.new(centralWidget(), “Widget”)  
@MenuBar.setProperty( “geometry”,  
Qt::Variant.new(Qt::Rect.new(0, 0,  
409, 29) ) )  
@StatusBar = Qt::StatusBar.new(centralWidget(), “StatusBar”)  
languageChange()  
resize( Qt::Size.new(409, 580).expandedTo(minimumSizeHint()) )  
clearWState( WState\_Polished )  
end  
#  
# Sets the strings of the subwidgets using the current  
# language.  
#  
def languageChange()  
setProperty(“windowTitle”,  
Qt::Variant.new(trUtf8(“MainWindow”)))  
end  
protected :languageChange  
end  
if $0 == **FILE**  
a = Qt::Application.new(ARGV)  
w = MainWindow.new  
a.mainWidget = w  
w.show  
a.exec  
end  
##################################################################

mainWindow.rb:24:in `initialize': undefined method`setProperty’ for  
nil:NilClass (NoMethodError)  
from mainWindow.rb:47:in `new’  
from mainWindow.rb:47

Thank you for you help.

## –

## “El mundo no está en peligro por las malas personas sino por las buenas personas que permiten la maldad.” Albert Einstein.

Star Wars: Episodio V - El imperio contraataca:  
Ten cuidado de la ira, del miedo, de la agresividad. el Lado Oscuro  
ellos son.  
Una vez que entras en el sendero Oscuro dominará tu destino para  
siempre.

---

<div class="post-metadata">

**Author:** ![GermSSSSn\_alberto\_G](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/439d5e/32.png) [@GermSSSSn\_alberto\_G](https://www.ruby-forum.com/u/GermSSSSn_alberto_G)\
**Post date:** [July 17, 2007, 2:56pm UTC](https://www.ruby-forum.com/t/qtruby-error/109640/2 "2007-07-17T14:56:13Z")

</div>

> rbuic mainWindow.ui \> mainWindow.rb

You’re mixing QtRuby versions here. The rbuic you are using is for  
QtRuby for Qt3.  
You probably need to use rbuic4 (that’s what it’s called on my system).

Caleb

---

<div class="post-metadata">

**Author:** ![GermSSSSn\_alberto\_G](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/439d5e/32.png) [@GermSSSSn\_alberto\_G](https://www.ruby-forum.com/u/GermSSSSn_alberto_G)\
**Post date:** [July 17, 2007, 3:04pm UTC](https://www.ruby-forum.com/t/qtruby-error/109640/3 "2007-07-17T15:04:15Z")

</div>

El Tuesday 17 July 2007 09:51:37 Caleb T.  
escribió:\> \> rbuic mainWindow.ui \> mainWindow.rb

> You’re mixing QtRuby versions here. The rbuic you are using is for QtRuby  
> for Qt3. You probably need to use rbuic4 (that’s what it’s called on my  
> system).
> 
> Caleb

It’s working with rbuic4  
Sorry my stupid question.

Thank you very much.

## –

## “El mundo no está en peligro por las malas personas sino por las buenas personas que permiten la maldad.” Albert Einstein.

Star Wars: Episodio V - El imperio contraataca:  
Ten cuidado de la ira, del miedo, de la agresividad. el Lado Oscuro  
ellos son.  
Una vez que entras en el sendero Oscuro dominará tu destino para siempre.