Android Question error while trying to load page

[Makumbi]

B4XMainPage - 437: Object reference not set to an instance of an object.
B4XMainPage - 435: Unknown member: get
B4XMainPage - 434: Index was out of range. Must be non-negative and less than the size of the collection.<br />Parameter name: index
B4XMainPage - 420: Current declaration does not match previous one.

Private Sub FetchFromAPIAndSearch(paycode As String)
    Dim j As HttpJob
    j.Initialize("", Me)
    j.Download("https://myapi//")
    
    Wait For (j) JobDone(j As HttpJob)
    
    If j.Success Then
        Try
            Dim parser As JSONParser
            parser.Initialize(j.GetString)
            
            ' Get the array from JSON
            Dim students As List = parser.NextArray
            Dim found As Boolean = False
            
            ' Check if the list is not empty
            If students.Size > 0 Then
                ' Iterate through the list using For Each
                For Each student As Map In students
                    ' Try to get Paycode safely
                    Dim StudentPaycode As String = ""
                
                    If StudentPaycode = paycode Then
                        found = True
                        
                        ' Get student details safely
                        Dim regNo As String = ""
                        Dim name As String = ""
                        Dim className As String = ""
                        Dim stream As String = ""
                        Dim account As String = ""
                        
                        Try
                            regNo = student.Get("RegNo")
                        Catch
                            regNo = ""
                        End Try
                        
                        Try
                            name = student.Get("Name")
                        Catch
                            name = ""
                        End Try
                        
                        Try
                            className = student.Get("Class")
                        Catch
                            className = ""
                        End Try
                        
                        Try
                            stream = student.Get("Stream")
                        Catch
                            stream = ""
                        End Try
                        
                        Try
                            account = student.Get("Account")
                        Catch
                            account = ""
                        End Try
                        
                        Dim dateFetched As String = DateTime.Date(DateTime.Now)
                        
                        'Save to database - using local db variable
                        db.BeginTransaction
                        Try
                            Dim cursor As ResultSet = db.ExecQuery2("SELECT id FROM students WHERE reg_no = ?", Array As String(regNo))
                            If cursor.NextRow Then
                                Dim updateQuery As String = "UPDATE students SET Name = ?, Class = ?, Stream = ?, account = ?, Paycode = ?, date_fetched = ? WHERE reg_no = ?"
                                db.ExecNonQuery2(updateQuery, Array As String(name, className, stream, account, StudentPaycode, dateFetched, regNo))
                            Else
                                Dim insertQuery As String = "INSERT INTO students (reg_no, Name, Class, Stream, account, Paycode, date_fetched) VALUES (?, ?, ?, ?, ?, ?, ?)"
                                db.ExecNonQuery2(insertQuery, Array As String(regNo, name, className, stream, account, StudentPaycode, dateFetched))
                            End If
                            cursor.Close
                            db.TransactionSuccessful
                            UpdateStatus
                        Catch
                            db.Rollback
                            Log("Error saving: " & LastException.Message)
                        End Try
                        
                        ShowStudentDetails(regNo, name, className, stream, account, StudentPaycode)
                        lblStatus.Text = $"✓ Paycode found for ${name}"$
                        Exit
                    End If
                Next
            End If
            
            'If Not found Then
            '    xui.MsgboxAsync($"No student found with Paycode: ${paycode}"$, "Not Found")
                'lblStatus.Text = "✗ Paycode not found in API"
            'End If
        Catch
            lblStatus.Text = "Error parsing data: " & LastException.Message
            Log("Error: " & LastException.Message)
        End Try
    Else
        lblStatus.Text = "Error fetching data: " & j.ErrorMessage
        xui.MsgboxAsync("Failed to fetch data from API", "Error")
    End If
    j.Release
End Sub

 

[aeric]

I think you have removed the code that caused the error.
Make sure you do not have this line:

Dim student As List 'singular

 

[mikelwillioms]

1. The error indicates that the page is failing because of an object/reference issue in the code.
2. “Object reference not set” usually means a required object was not initialized before use.
3. “Index was out of range” means the code is trying to access an invalid collection position.
4. “Unknown member: get” suggests the requested property or method is not available in the current object/API response.
5. For a Police Clearance website, verify the API response, initialize objects properly, and validate indexes before accessing the data.