Android Question B4xpages problem, Java code

[james_sgp]

Hi, I have the following code working fine in a non B4xpages app, but trying to use it in a B4xpages app I`m getting an error. The code is:

Sub GetRndNonRepeatingList(lSize As Int, rnMin As Int, rnMax As Int) As List
    Dim llist As List
    Dim nr As Int
    llist.Initialize
    Private nNativeMe As JavaObject
    nNativeMe.InitializeContext
    If rnMax+1>=lSize And rnMin<rnMax Then
        Do While llist.Size< lSize
            nr=nNativeMe.RunMethod("GetRndJAVAInt", Array(rnMin,rnMax))
            If llist.IndexOf(nr)=-1 Then
                llist.Add(nr)
            End If
        Loop
    End If
    Return llist
End Sub

#If JAVA
import java.util.Random;
Public static int GetRndJAVAInt(int Min, int Max) {
    Random random = new Random();
    Return random.nextInt((Max - Min) + 1) + min;
}
#End If

Which is giving me the error:

*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create (first time) **
Call B4XPages.GetManager.LogEvents = True to enable logging B4XPages events.
** Activity (main) Resume **
Error occurred on line: 350 (B4XMainPage)
java.lang.RuntimeException: Method: GetRndJAVAInt not found in: raid.quiz2.main
    at anywheresoftware.b4j.object.JavaObject$MethodCache.getMethod(JavaObject.java:363)
    at anywheresoftware.b4j.object.JavaObject.RunMethod(JavaObject.java:120)
    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 raid.quiz2.b4xmainpage._getrndnonrepeatinglist(b4xmainpage.java:442)
    at raid.quiz2.b4xmainpage._build_question_list(b4xmainpage.java:412)
    at raid.quiz2.b4xmainpage._g2_cat2_click(b4xmainpage.java:942)
    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 anywheresoftware.b4a.BA.raiseEvent(BA.java:201)
    at anywheresoftware.b4a.objects.ViewWrapper$1.onClick(ViewWrapper.java:80)
    at android.view.View.performClick(View.java:7869)
    at android.widget.TextView.performClick(TextView.java:14958)
    at android.view.View.performClickInternal(View.java:7838)
    at android.view.View.access$3600(View.java:886)
    at android.view.View$PerformClick.run(View.java:29362)
    at android.os.Handler.handleCallback(Handler.java:883)

I can`t for the life of me see what I`m doing wrong...

Thanks in advance, James

 

[Johan Schoeman]

The "Return" in the java code must be "return" I.e lower case "r". Not sure if that will solve your problem but I think it must be a lower case "r".

 

[agraham]

If you use InitializeContext then RunMethod looks for the Sub in the current Activity, but in B4XPages your Sub is located in the current page class.
Try
nNativeMe = Me
instead of
nNativeMe .InitializeContext.

 

[LucaMs]

https://www.b4x.com/android/forum/threads/b4x-class-clsrnditems.136776/#content

 

[RB Smissaert]

Hi, I have the following code working fine in a non B4xpages app, but trying to use it in a B4xpages app I`m getting an error. The code is:

Sub GetRndNonRepeatingList(lSize As Int, rnMin As Int, rnMax As Int) As List
    Dim llist As List
    Dim nr As Int
    llist.Initialize
    Private nNativeMe As JavaObject
    nNativeMe.InitializeContext
    If rnMax+1>=lSize And rnMin<rnMax Then
        Do While llist.Size< lSize
            nr=nNativeMe.RunMethod("GetRndJAVAInt", Array(rnMin,rnMax))
            If llist.IndexOf(nr)=-1 Then
                llist.Add(nr)
            End If
        Loop
    End If
    Return llist
End Sub

#If JAVA
import java.util.Random;
Public static int GetRndJAVAInt(int Min, int Max) {
    Random random = new Random();
    Return random.nextInt((Max - Min) + 1) + min;
}
#End If

Which is giving me the error:

*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create (first time) **
Call B4XPages.GetManager.LogEvents = True to enable logging B4XPages events.
** Activity (main) Resume **
Error occurred on line: 350 (B4XMainPage)
java.lang.RuntimeException: Method: GetRndJAVAInt not found in: raid.quiz2.main
    at anywheresoftware.b4j.object.JavaObject$MethodCache.getMethod(JavaObject.java:363)
    at anywheresoftware.b4j.object.JavaObject.RunMethod(JavaObject.java:120)
    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 raid.quiz2.b4xmainpage._getrndnonrepeatinglist(b4xmainpage.java:442)
    at raid.quiz2.b4xmainpage._build_question_list(b4xmainpage.java:412)
    at raid.quiz2.b4xmainpage._g2_cat2_click(b4xmainpage.java:942)
    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 anywheresoftware.b4a.BA.raiseEvent(BA.java:201)
    at anywheresoftware.b4a.objects.ViewWrapper$1.onClick(ViewWrapper.java:80)
    at android.view.View.performClick(View.java:7869)
    at android.widget.TextView.performClick(TextView.java:14958)
    at android.view.View.performClickInternal(View.java:7838)
    at android.view.View.access$3600(View.java:886)
    at android.view.View$PerformClick.run(View.java:29362)
    at android.os.Handler.handleCallback(Handler.java:883)

I can`t for the life of me see what I`m doing wrong...

Thanks in advance, James

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