Android Code Snippet Using StartActivityForResult with JavaObject

Discussion in 'Code Snippets' started by Erel, Apr 28, 2014.

  1. Erel

    Erel Administrator Staff Member Licensed User

    SubName: StartActivityForResult

    Description: This code demonstrates how JavaObject can be used to call external APIs that should be called with Context.startActivityForResult.

    This code should be added to an Activity. You should also declare a process global variable named ion:
    Sub Process_Globals
    Private ion As Object
    End Sub
    Sub ion_Event (MethodName As String, Args() As Object) As Object
    'Args(0) = resultCode
    'Args(1) = intent
    Return Null
    End Sub

    Sub StartActivityForResult(i As Intent)
    Dim jo As JavaObject = GetBA
       ion = jo.CreateEvent(
    "startActivityForResult"Array As Object(ion, i))
    End Sub

    Sub GetBA As Object
    Dim jo As JavaObject
    Dim cls As String = Me
       cls = cls.SubString(
    "class ".Length)
    Return jo.GetField("processBA")
    End Sub
    For example we can show the Ringtone picker with this code:
    Sub Activity_Create(FirstTime As Boolean)
    If FirstTime Then
    End If   
    End Sub

    Sub ShowPicker
    Dim i As Intent
    End Sub

    Sub ion_Event (MethodName As String, Args() As Object) As Object
    If Args(0) = -1 Then 'resultCode = RESULT_OK
         Dim i As Intent = args(1)
    Dim jo As JavaObject = i
    Dim uri As String = jo.RunMethod("getParcelableExtra", _
    Array As Object("android.intent.extra.ringtone.PICKED_URI"))
    End If
    Return Null
    End Sub
    Dependencies: JavaObject v1.20+

    Tags: StartActivityForResult, OnActivityResult
    Last edited: Apr 28, 2014
    smercan, wonder, pesquera and 5 others like this.
  2. NJDude

    NJDude Expert Licensed User

    Could this be added to the B4A core?, I think it would be more practical that way than having a code snippet.
    MarkusR and thedesolatesoul like this.
  3. Erel

    Erel Administrator Staff Member Licensed User

    Accessing external APIs is an advanced issue which will usually require usage of JavaObject to extract the data. You can make a code module out of this code. Or compile it into a library. The result will be the same.
  4. LucaMs

    LucaMs Expert Licensed User

    It is possible to use it also to call internal activities? (Yes, you've already responded to me that I can use CallSubDelayed, but you did not developed this at that time :))
  5. Erel

    Erel Administrator Staff Member Licensed User

    There are no advantages for this method over CallSubDelayed. CallSubDelayed is simpler to use and is actually more powerful (for internal activities).
  6. bluedude

    bluedude Well-Known Member Licensed User

    Could you provide a sample for the contactlist? I only target Android 4.x so I guess that will always work.
  7. Erel

    Erel Administrator Staff Member Licensed User

    1. Add the following permission to the manifest editor:
    2. Use the following code:
    Sub Activity_Click
    Dim i As Intent
    End Sub

    Sub ion_Event (MethodName As String, Args() As Object) As Object
    If Args(0) = -1 Then 'resultCode = RESULT_OK
         Dim i As Intent = args(1)
    Dim id As String = i.GetData.SubString(i.GetData.LastIndexOf("/") + 1)
    Dim cu As ContactsUtils
    End If
    Return Null
    End Sub
    Add the following sub to ContactsUtils:
    Public Sub GetNameFromId (id As StringAs String
    Dim crsr As Cursor = cr.Query(dataUri, Array As String("contact_id""display_name"), "contact_id = ?", _
    Array As String(id), "")
    Dim name As String
    If crsr.RowCount = 0 Then
    Log("Contact not found: " & id)
         crsr.Position = 
         name = crsr.GetString2(
    End If
    Return name
    End Sub
    peacemaker, smercan and fabricio like this.
  8. bluedude

    bluedude Well-Known Member Licensed User

    Right, will try it! Don't want to create my own activities for contact picking.
  9. bluedude

    bluedude Well-Known Member Licensed User

    Works great but wondering how to get the email address of the user? Tried a few things but could not get it.
  10. Erel

    Erel Administrator Staff Member Licensed User

    Have you tried ContactsUtils.GetEmails?
  11. bluedude

    bluedude Well-Known Member Licensed User

    That seems to work.
  12. geodesic

    geodesic New Member Licensed User

    I may be missing something obvious, but I am still a novice and trying to figure out how values are reflected between Java and b4a. I had a need for an intent with a return, so I copied this code (almost) except I substituted ACCOUNT_PICKER instead of RINGTONE_PICKER.

    My first attempt to read the return value failed, using the code:
    account = jo.RunMethod("getStringExtra"Array As Object("android.accounts.AccountManager.KEY_ACCOUNT_NAME"))
    The result came back null. Strange, as eventually I figured out how to stop in the debugger and analyze the variables which clearly showed the data in jo.mExtras.mMap.mArray

    I then changed the code to:

    account = jo.RunMethod("getStringExtra"Array As Object("authAccount"))
    And everything worked.

    I am very puzzled why this is, since android.accounts.AccountManager.KEY_ACCOUNT_NAME is defined with constant value "authAccount". Is this because:

    A) There is something wrong with my code
    B) Because of a bug in b4a
    C) Because there is a library missing and b4a can't evaluate the variable
    D) Something else that I am not considering

    If someone can answer this and explain to me what I should have done to save myself several hours of struggling it would be helpful for my education.

    If the answer is C, how can I know which android.* libraries are included by default and which ones are not? There certainly were not any warning messages displayed.

    Thank you for any assistance.
  13. Erel

    Erel Administrator Staff Member Licensed User

    You are confusing the constant name (variable name) with the actual value. The value is "authAccount". You have passed a different string, so it didn't work.

    Note that you can get the constant value with:
    Dim v As JavaObject
    Dim constValue As String = v.InitializeStatic("android.accounts.AccountManager").GetField("KEY_ACCOUNT_NAME")
  14. TheMightySwe

    TheMightySwe Active Member Licensed User


    We have a java app that connects to a Cardterminal that has the name "se.iqpd.checkout.companion". We start that in B4A with the following code.

    Dim ISMP_Intent As Intent
    Dim InstalledPackages As PackageManager
        ISMP_Intent = InstalledPackages.GetApplicationIntent(
    We send the return with following JAVA-code

    Intent output = new Intent();
    ' Lots of  otherresultdata that we cant post because of confidentiallity agreement  
                getParent().setResult(Activity.RESULT_OK, output);

    But in B4A we get a error, nothing returns.

    Why is that, anyone knows?

    // TMS
    Last edited: Nov 5, 2014
  15. Erel

    Erel Administrator Staff Member Licensed User

    Please start a new thread for this question.
  16. TheMightySwe

    TheMightySwe Active Member Licensed User


    StartActivityForResult code seems to call up the "Complete Action Using" - dialog after 4.30 update, anyone know why, and what to do to suppress it?

    It happens in all calls to StartActivityForResult in my app.

    Just an example

    Sub StartEmail

    Dim Email_Intent As Intent
    Dim InstalledPackages As PackageManager
        Email_Intent = InstalledPackages.GetApplicationIntent(


    End Sub
  17. Erel

    Erel Administrator Staff Member Licensed User

    I'm pretty sure that it is not related to v4.30.

    You can explicitly set the package name of the intent with:
    Dim jo As JavaObject = Email_Intent
  18. TheMightySwe

    TheMightySwe Active Member Licensed User

    Solved it with this. But your solution seems better.

  19. b4auser1

    b4auser1 Well-Known Member Licensed User

    I used the code from the thread to pick a contact from Contacts intent and it worked good until Android 5.1.
    On Nexus 5 with Android 5.1 it shows contacts list, but after selecting a contact nothing happened.
    I checked the same apk on device with Android 4.4.2, 5.0.2 and there everything is Ok.
  20. b4auser1

    b4auser1 Well-Known Member Licensed User

    ion_Event is not called under Android 5.1
    only "onActivityResult: IOnActivityResult was released" messaged is in Log.
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice