B4J Question Error to do with rootpane, mainpain and other panes [Solved]

[Peter Lewis]

Hi All

I think my understanding of the panes could be the problem

Please can someone explain it to me when I am going wrong

I have an app with my main code module

    MainForm = Form1
    MainForm.RootPane.LoadLayout("RootLayout") 'Load the layout file.

then I got another Code module called playgame

    Main.RootPane.RemoveAllNodes
    Main.RootPane.LoadLayout("playgame") 'Load the layout file

Up to this point every thing works well

When I want to change the colour of one of the buttons in the layout

form.Stylesheets.Add(File.GetUri(File.DirAssets, "RedButton.css"))
    form.Show

I get an error on the first line

What is the best selling album of all time from 1976 to 2018?
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Error occurred on line: 88 (PLAYGAME)
java.lang.NullPointerException
at anywheresoftware.b4j.objects.Form.getStylesheets(Form.java:292)
at b4j.quiz.playgame._getquestion(playgame.java:245)
at b4j.quiz.playgame._start(playgame.java:80)
at b4j.quiz.joingame._timer2_tick(joingame.java:774)
at jdk.internal.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:632)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:237)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:167)
at jdk.internal.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:91)
at anywheresoftware.b4a.shell.ShellBA.raiseEvent2(ShellBA.java:98)
at anywheresoftware.b4a.objects.Timer$TickTack$1.run(Timer.java:118)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:428)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
at java.base/java.lang.Thread.run(Thread.java:834)

Thank you

 

[Erel]

How is form created? Looks like it wasn't initialized.

 

[Peter Lewis]

How is form created? Looks like it wasn't initialized.

It was created using the internal designer but i am using the other method you suggested SwiftButton

btn1.xLBL.Color=xui.Color_Green

 

[Erel]

The designer doesn't create forms. It creates layout files that are loaded to pane(l)s.

Where does the variable 'form' come from?

 

[Peter Lewis]

I made that variable the same at the Form name of the root of the designer , but the SwiftButtons work perfectly

I thought it was a form as it said Form title , MyBad

 

[Erel]

No. See the three pages example: https://www.b4x.com/android/forum/threads/getting-started-examples.57537/#content

 

[Peter Lewis]

No. See the three pages example: https://www.b4x.com/android/forum/threads/getting-started-examples.57537/#content

Perfect, thank you. I will learn a lot from that. I learn better by example