Android Question java.lang.RuntimeException: Object should first be initialized (B4XView).

Best if you upload the project (Ctrl + 1 will create a zip file if using latest version of B4A).

Did you also declare
Private lblNumber2 As B4XView
in the Class_Globals routine ?

This is what the example program generated from the designer stage - see the script from the guide



Then the guide says to add the Number1 and Number2 variables to the same routine



Are you sayng that this is wrong ?

Hello !
I have partly moved on from my problem, but not very far ! The program is coded as below - some lines have been given numbers for clarity
Th initialise problem is not listed as an error since I put in the extra coding to assign values to the variables ( I hope this is correct). I have not put the Design here but I have (hopefully) attached a zipped version of the program to this request.

The progam now completes a compilation, and my Android device , whilst apparently allowing it to run, closes immediately and the following message apppear on the log file

Once again thanks to anyone who can help - If I can't get this basic program to work then I cannot continue !

The top LOG files read (after compilation)

Main - 25: Layout file 'program01.bal' is not used. Are you missing a call to Activity.LoadLayout? (warning #16)

The main LOG file read as below, saying that there was a problem with line 28 lblNumber1.Text = Number1

Logger connected to: motorola moto g15
--------- beginning of main
*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create (first time) **
Error occurred on line: 28 (B4XMainPage)
java.lang.RuntimeException: Type does not match (class java.lang.String)
at anywheresoftware.b4a.objects.B4XViewWrapper.typeDoesNotMatch(B4XViewWrapper.java:405)
at anywheresoftware.b4a.objects.B4XViewWrapper.asLabelWrapper(B4XViewWrapper.java:215)
at anywheresoftware.b4a.objects.B4XViewWrapper.setText(B4XViewWrapper.java:229)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:348)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:157)
at anywheresoftware.b4a.debug.Debug.delegate(Debug.java:262)
at b4a.Program01.b4xmainpage._newproblem(b4xmainpage.java:72)
at b4a.Program01.b4xmainpage._b4xpage_created(b4xmainpage.java:63)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.debug.Debug.CallSub4(Debug.java:318)
at anywheresoftware.b4a.debug.Debug.CallSubNew2(Debug.java:285)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.keywords.Common.CallSubDebug2(Common.java:1140)
at b4a.Program01.b4xpagesmanager._createpageifneeded(b4xpagesmanager.java:1068)
at b4a.Program01.b4xpagesmanager._showpage(b4xpagesmanager.java:425)
at b4a.Program01.b4xpagesmanager._addpage(b4xpagesmanager.java:245)
at b4a.Program01.b4xpagesmanager._addpageandcreate(b4xpagesmanager.java:259)
at b4a.Program01.b4xpagesmanager._initialize(b4xpagesmanager.java:165)
at b4a.Program01.main._activity_create(main.java:415)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:351)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:157)
at b4a.Program01.main.afterFirstLayout(main.java:105)
at b4a.Program01.main.access$000(main.java:17)
at b4a.Program01.main$WaitForLayout.run(main.java:83)
at android.os.Handler.handleCallback(Handler.java:959)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loopOnce(Looper.java:234)
at android.os.Looper.loop(Looper.java:319)
at android.app.ActivityThread.main(ActivityThread.java:8754)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:962)

There was more if needed !

The Program

#Region Shared Files
#CustomBuildAction: folders ready, %WINDIR%\System32\Robocopy.exe,"..\..\Shared Files" "..\Files"
'Ctrl + click to sync files: ide://run?file=%WINDIR%\System32\Robocopy.exe&args=..\..\Shared+Files&args=..\Files&FilesSync=True
#End Region

Sub Class_Globals
Private Root As B4XView
Private xui As XUI
Private btnAction As B4XView = "Enter the result" & CRLF & "and click on OK"
Private edtResult As B4XView = " "
Private lblComments As B4XView = " "
Private lblMathSign As B4XView = "+"
Private lblNumber1 As B4XView = "0"
Private lblNumber2 As B4XView = "0"
Public Number1,Number2 As Int
End Sub
Public Sub Initialize
' B4XPages.GetManager.LogEvents = True
End Sub
Private Sub B4XPage_Created (Root1 As B4XView)
Root = Root1
Root.LoadLayout("MainPage")
NewProblem
End Sub
Private Sub NewProblem
26 Number1 = Rnd(1,10)
27 Number2 = Rnd(1,10)
28 lblNumber1.Text = Number1
29 lblNumber2.Text = Number2
30 lblComments.Text = "Enter the result" & CRLF & "and click on OK"
edtResult.Text = ""
lblMathSign.Text = "+"
End Sub

Private Sub Button1_Click
If btnAction.Text = "O K" Then
If edtResult.Text = "" Then
MsgboxAsync("No result entered", "E R R O R")
Else
CheckResult
End If
Else
NewProblem
btnAction.Text = "O K"
End If
End Sub
Private Sub CheckResult
If edtResult.Text = Number1 + Number2 Then
lblComments.Text = "G O O D result" & CRLF & "Click on NEW"
btnAction.Text = "NEW"
Else
lblComments.Text = "Wrong result " & CRLF & "Try again " & CRLF & "Click OK"
End If
End Sub

1. The problem is that you load the MainForm layout file.
But your layout file is ProGram01, so need to load this one.

2. Then, you have this line, which is wrong:
It should be:

3. In the Designer you should set the TextSize parameters for the three upper Labels and the EditText view to 36 instead of 14.

4. The lblComments does not show anything because its background color is white and the text color is also white.
Set to black.
You might also increase its TextSize.

That’s brilliant – thanks so much – I thought that I had renamed btnAction but missed that one. The program basically works on my Android now, I usually find that mistakes like mine are more likely to make me remember them than if I get them right first time. I can now look at writing something useful. Thanks Again !!