Android Question [B4X] [B4XPages] Barcode Reader - How to take a Picture

[imbault]

Hi, using the example given by @Erel , I just add:

camEx.TakePicture in StopCamera like that :

Private Sub StopCamera
    Capturing = False
    btnStartStop.Text = "Start"
    ' here Add camEx.TakePicture
    camEx.TakePicture
    pnlPreview.Visible = False
    #if B4A
    If camEx.IsInitialized Then
        camEx.Release
    End If
    #Else If B4i
    scanner.Stop
    #end if
End Sub

Then add Camera1_PictureTaken like that :

Sub Camera1_PictureTaken (Data() As Byte)
    Dim filename As String = "1.jpg"
    Dim dir As String = File.DirInternal
    
    camEx.SavePictureToFile(Data, dir, filename)
    camEx.StartPreview 'restart preview
End Sub

When I compile, I got :
cameraexclass_takepicture (java line: 881)
java.lang.NullPointerException: Attempt to invoke virtual method 'void anywheresoftware.b4a.objects.CameraW.TakePicture()' on a null object reference
at b4a.example.cameraexclass._takepicture(cameraexclass.java:881)
at b4a.example.b4xmainpage._stopcamera(b4xmainpage.java:378)
at b4a.example.b4xmainpage._b4xpage_created(b4xmainpage.java:53)
at b4a.example.b4xmainpage.callSub(b4xmainpage.java:392)
at anywheresoftware.b4a.keywords.Common.CallSub4(Common.java:1066)
at anywheresoftware.b4a.keywords.Common.CallSubNew2(Common.java:1037)
at b4a.example.b4xpagesmanager._createpageifneeded(b4xpagesmanager.java:498)
at b4a.example.b4xpagesmanager._showpage(b4xpagesmanager.java:800)
at b4a.example.b4xpagesmanager._addpage(b4xpagesmanager.java:198)
at b4a.example.b4xpagesmanager._addpageandcreate(b4xpagesmanager.java:205)
at b4a.example.b4xpagesmanager._initialize(b4xpagesmanager.java:681)
at b4a.example.main._activity_create(main.java:366)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:213)
at b4a.example.main.afterFirstLayout(main.java:105)
at b4a.example.main.access$000(main.java:17)
at b4a.example.main$WaitForLayout.run(main.java:83)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:237)
at android.app.ActivityThread.main(ActivityThread.java:7948)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1075)


Any clue, please?


Patrick

 

[Erel]

Why are you calling TakePicture from the stop method? It closes the camera.