Android Question CallSub in B4x

[Sinan Tuzcu]

Hi,

I have in a B4xPage class a button with CallSub2 Method

Private Sub btn_continue_Click
    StopCamera
    Log(Variablen.GeleseneText)
    '
    CallSub2(GeneralSettings,"QRcodeTextLesen",Variablen.GeleseneText)
    B4XPages.ClosePage(Me)
    StartActivity(GeneralSettings)
End Sub

the page will closed and Page Generalsettings will open but CallSub in Generalsettings has no reaction.

Sub QRcodeTextLesen(msg as String)
    Log("Aufgerufen")
    Dim Trenner() As String
    Trenner = Regex.Split("\|",msg )
    txtVorname.text = Trenner(0)
    txtNachname.Text = Trenner(1)
    txtemail.Text = Trenner(2)
    txtPW_Login.Text = Trenner(3)
   
End Sub

I get no error code and no warning

 

[Andrew (Digitwell)]

Why are you using "StartActivity" in a b4xpages app?

This is what I normally do to pass data to a B4xpage class

    Private b4xp As B4xpageClass = B4XPages.GetPage("B4xPageClass")  'Already initialised the class elsewhere with b4xpages.AddPage
    B4XPages.ShowPage("B4xPageClass")
    b4xp.QRcodeTextLesen(data)
    B4XPages.ClosePage(Me)

 

[Sinan Tuzcu]

I have started with this app 3 years ago and include StartActivity and so on.
Now, I can not change to B4X version, because the App has lot of codes an pages.
I have try it, to change but I get lot of Errors and then I have see, I need lot of time for this.

Now, I have implement the example from

[B4X] [B4XPages] Barcode Reader

B4A + B4i barcode reader. Don't miss: - #PlistExtra in B4i. - Manifest code + #AdditionalJar in B4A Depends on BCToast: https://www.b4x.com/android/forum/threads/b4x-bctoast-cross-platform-custom-toast-message.111046/#content (BCToast will be an internal library in the near future) While the...

www.b4x.com

and now I need, how can I pass data from B4XClass to activity pages.
And how cann use CallSub ??

Your Method not works at me

I hoppe you can understand me

 

[Andrew (Digitwell)]

It looks like you are trying to use both methods in the same app.

The problem is probably that the activity has not yet started and so the CallSub is lost.

Try using CallSubDelayed as per this example, it seems that it will start the activity.

Using CallSubDelayed to interact between activities and services

Until Basic4android v2.00 the way to pass information between activities and services was through process global variables. CallSubDelayed makes it much simpler. It allows you to call a sub in a different service or activity. If the target module is not active, then it will be started...

www.b4x.com

 

[Sinan Tuzcu]

Then I get this following error

Error occurred on line: 0 (GeneralSettings)
java.lang.Exception: Sub qrcodetextlesen signature does not match expected signature.
public static anywheresoftware.b4a.pc.RemoteObject yamutec.app.generalsettings_subs_0._qrcodetextlesen() throws java.lang.Exception

class java.lang.String,

Pointed in the Activity (GeneralSettings) top firstline
#Region Activity Attributes
#FullScreen: False
#IncludeTitle: False
#End Region

 

[Andrew (Digitwell)]

Are you calling

Callsubdelayed2(GeneralSetting,"QRcodeTextLesen",data)

as you are passing 1 parameter?

You can check if the sub exists by calling

xui.subexists(GeneralSettings,"QRcodeTextLesen",1) befordhand

 

[Sinan Tuzcu]

this is my code in B4XMainPage Class

Private Sub btn_continue_Click
    
    StopCamera
    Log(Variablen.GeleseneText)
    
    
    xui.subexists(GeneralSettings,"QRcodeTextLesen",1)
    
    StartActivity("GeneralSettings")
    
    CallSubDelayed2(GeneralSettings,"QRcodeTextLesen",Variablen.GeleseneText)
    'B4XPages.ClosePage(Me)
    
End Sub

Sub in Generalsettings Activity

Sub QRcodeTextLesen(msg As String)
    
    Dim Trenner() As String
    
    Trenner = Regex.Split("\|",msg)
    txtVorname.text = Trenner(0)
    txtNachname.Text = Trenner(1)
    txtemail.Text = Trenner(2)
    txtPW_Login.Text = Trenner(3)
    
End Sub

Get Error:

Error occurred on line: 0 (GeneralSettings)
java.lang.Exception: Sub qrcodetextlesen signature does not match expected signature.
public static anywheresoftware.b4a.pc.RemoteObject yamutec.app.generalsettings_subs_0._qrcodetextlesen() throws java.lang.Exception

class java.lang.String,

 

[Andrew (Digitwell)]

xui.subexists(GeneralSettings,"QRcodeTextLesen",1) returns a boolean so the correct code should be:

StartActivity("GeneralSettings")

if  xui.subexists(GeneralSettings,"QRcodeTextLesen",1) then
    CallSubDelayed2(GeneralSettings,"QRcodeTextLesen",Variablen.GeleseneText)
else
    Log("QRcodeTextLesen does not exist on General Settings")
end if

 

[Sinan Tuzcu]

it is same behavior

Get:

Error occurred on line: 0 (GeneralSettings)
java.lang.Exception: Sub qrcodetextlesen signature does not match expected signature.
public static anywheresoftware.b4a.pc.RemoteObject yamutec.app.generalsettings_subs_0._qrcodetextlesen() throws java.lang.Exception

class java.lang.String,

 

[Andrew (Digitwell)]

Very odd.
I will write a sample program in the morning.

 

[Sinan Tuzcu]

Is it possible, do this without B4X
I mean by use only Activity and StartActivity?

 

[Andrew (Digitwell)]

Yes. Just use a global variable?

 

[Sinan Tuzcu]

I have try it, but not works
No error log

I don't know what is the issue.

 

[Andrew (Digitwell)]

This works as expected on my device. No b4xpages just activities. Press the button on main and the messagebox from activity2 appears.

Your example upload seems to be missing GeneralSettings

Main Activity

#Region  Project Attributes 
    #ApplicationLabel: B4A Example
    #VersionCode: 1
    #VersionName: 
    'SupportedOrientations possible values: unspecified, landscape or portrait.
    #SupportedOrientations: unspecified
    #CanInstallToExternalStorage: False
#End Region

#Region  Activity Attributes 
    #FullScreen: False
    #IncludeTitle: True
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.
    Private xui As XUI
End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
End Sub

Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("Layout")
End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

Sub Button1_Click
    CallSubDelayed2(Activity2,"callme","Test string")
End Sub

Activity 2

#Region  Activity Attributes 
    #FullScreen: False
    #IncludeTitle: True
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.
    Private xui As XUI
End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    'Activity.LoadLayout("Layout1")

End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

Sub callme(param As String)
    xui.MsgboxAsync(param,"Test")
End Sub

 

[Sinan Tuzcu]

Hi Andrew,

your sample is only activity. For pass parameter beetwen two aktivities is not problem.
The question was, pass parameter from B4Xpages to activity

 

[Andrew (Digitwell)]

Is it possible, do this without B4X
I mean by use only Activity and StartActivity?

You did say you only wanted Activity.
But,
Here is a Pages to Activity Example.

It is much the same.

#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

'Ctrl + click to export as zip: ide://run?File=%B4X%\Zipper.jar&Args=pagestoactviity.zip

Sub Class_Globals
    Private Root As B4XView
    Private xui As XUI
End Sub

Public Sub Initialize
'    B4XPages.GetManager.LogEvents = True
End Sub

'This event will be called once, before the page becomes visible.
Private Sub B4XPage_Created (Root1 As B4XView)
    Root = Root1
    Root.LoadLayout("MainPage")
End Sub

'You can see the list of page related events in the B4XPagesManager object. The event name is B4XPage.

Private Sub Button1_Click
    CallSubDelayed2(Activity2,"callme","This is from b4xpages")
End Sub

#Region  Activity Attributes 
    #FullScreen: False
    #IncludeTitle: True
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.
    Private xui As XUI
End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    'Activity.LoadLayout("Layout1")

End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

public Sub callme(param As String)
    xui.MsgboxAsync(param,"Test")
End Sub

 

[Sinan Tuzcu]

Hi,
Your both sample dont works on my device. Msgbox dont appears.

 

[Andrew (Digitwell)]

What device do you have?

I have tried on a Redmi Note 8 Pro - Android 11
Samsung Galaxy Tab A - Android 7.11
Google Pixel 2 XL - Android 11
Honor 7 - Android 6.0

These are the phone I have charged on my desk and it works on all of these.

Not sure what could be going wrong.

 

[Sinan Tuzcu]

Sony G8141
Android 9