B4J Question (SOLVED)Application crashes when TableView items are cleared

[walterf25]

Hello all, i haven't really played too much with B4J, i'am working on a very simple application which connects to a remote database on my hosting service, i'am using a tableview which shows the results of a search query, this all works perfect, but when i clear the items from the tableview the application crashes with the following error.

Error occurred on line: 176 (Main)
java.lang.NullPointerException
at b4j.example.main._tblsearchresults_selectedrowchanged(main.java:367)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:612)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:226)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:159)
at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:90)
at anywheresoftware.b4a.BA$2.run(BA.java:165)
at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)

below is the relevant code, please let me know if there is anything i'm missing

Sub searchresults_QueryComplete (Success As Boolean, Crsr As ResultSet)
    Dim sql2 As SQL = Sender
    If Success Then
    Log("success retrieving searchresults: " & Success)
    If tblsearchresults.Items.Size > 0 Then
        tblsearchresults.Items.Clear  'Here i clear the items from the previous search
    End If
    Do While Crsr.NextRow
    Dim row(7) As Object
    Log("first name: " & Crsr.GetString("First_Name") & " " & "Last Name :" &       Crsr.GetString("Last_Name") & " " & "Pet's Name: " & Crsr.GetString("Pet_Name"))
    row(0) = Crsr.GetString("First_Name")
    row(1) = Crsr.GetString("Last_Name")
    row(2) = Crsr.GetString("Pet_Name")
    row(3) = Crsr.GetString("Sex")
    row(4) = Crsr.GetString("Breed")
    row(5) = Crsr.GetString("Date")
    row(6) = Crsr.GetString("Clips_and_Comments")
    tblsearchresults.Items.Add(row)
    Loop
    Crsr.Close
    sql2.Close
    searchresults.Show
    Else
    Log("error occurred retrieving search results")   
    End If
End Sub

Thanks All,
Walter

 

[walterf25]

Hello all, i haven't really played too much with B4J, i'am working on a very simple application which connects to a remote database on my hosting service, i'am using a tableview which shows the results of a search query, this all works perfect, but when i clear the items from the tableview the application crashes with the following error.



below is the relevant code, please let me know if there is anything i'm missing

Sub searchresults_QueryComplete (Success As Boolean, Crsr As ResultSet)
    Dim sql2 As SQL = Sender
    If Success Then
    Log("success retrieving searchresults: " & Success)
    If tblsearchresults.Items.Size > 0 Then
        tblsearchresults.Items.Clear  'Here i clear the items from the previous search
    End If
    Do While Crsr.NextRow
    Dim row(7) As Object
    Log("first name: " & Crsr.GetString("First_Name") & " " & "Last Name :" &       Crsr.GetString("Last_Name") & " " & "Pet's Name: " & Crsr.GetString("Pet_Name"))
    row(0) = Crsr.GetString("First_Name")
    row(1) = Crsr.GetString("Last_Name")
    row(2) = Crsr.GetString("Pet_Name")
    row(3) = Crsr.GetString("Sex")
    row(4) = Crsr.GetString("Breed")
    row(5) = Crsr.GetString("Date")
    row(6) = Crsr.GetString("Clips_and_Comments")
    tblsearchresults.Items.Add(row)
    Loop
    Crsr.Close
    sql2.Close
    searchresults.Show
    Else
    Log("error occurred retrieving search results")  
    End If
End Sub

Thanks All,
Walter

Sorry All, just figured it out, turns out i have to evaluate the index at the _SelectedRowChange event after clearing the items from the list.

Sub tblsearchresults_SelectedRowChanged(Index As Int, Row() As Object)
If Index > -1 Then
    Dim date As Long
    txtname.Text = Row(0)
    txtlast.Text = Row(1)
    txtpetname.Text = Row(2)
    txtsex.Text = Row(3)
    txtbreed.Text = Row(4)
    date = DateTime.DateParse(Row(5))
    txtdate.Date = date
    txtcomments.Text = Row(6)
    'tblsearchresults.Items.Clear
    searchresults.Close
End If
End Sub

Thanks all.
Walter