[2005] output to file

[robee31]

I am having a hard time why my code does not write to a file.

Private Sub btnEnter_Click(ByVal sender As System.Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnEnter.Click

        Dim values As String() = GetTextBoxValues()

        Dim record As New GradeBookDataCollector()

        Me.SetTextBoxValues(GetTextBoxValues)
        If values(TextBoxIndices.txtFirstName) <> "" Then

            Try
                Dim strFirstName As String = _
                    values(TextBoxIndices.txtFirstName)

                If strFirstName <> "" Then
                    record.strFirstName = values(TextBoxIndices.txtFirstName)
                    record.strLastName = values(TextBoxIndices.txtLastName)
                    record.strCourseName = values(ComboBoxIndices.cboCourseName)
                    record.strStudentId = values(TextBoxIndices.txtStudentId)
                    record.strGrade = values(ComboBoxIndices.cboGrade)

                    fileWriter.WriteLine( _
                    record.strFirstName.ToString & "," & record.strLastName.ToString & "," & _
                    record.strStudentId.ToString & "," & record.strCourseName.ToString & "," & _
                    record.strGrade.ToString)


                Else
                    MessageBox.Show("Invalid First Name", "Error", _
                    MessageBoxButtons.OK, MessageBoxIcon.Error)
                End If

            Catch ex As IOException
                MessageBox.Show("Error Writing to File", "Error", _
                MessageBoxButtons.OK, MessageBoxIcon.Error)

            Catch ex As FormatException
                MessageBox.Show("Invalid Format", "Error", _
               MessageBoxButtons.OK, MessageBoxIcon.Error)

            End Try
        End If

        Me.SetTextBoxValues(GetTextBoxValues)
        Me.ClearFormDataEntryBoxes()

    End Sub

[Atheist]

Where are you creating the fileWriter object? Have you stepped through your code to see what happens?

And you must turn Option Strict ON and fix the errors you get.

[jmcilhinney]

Also, you've already asked this question in another thread. Do NOT post the same question more than once. If you have more information to post then post it to the existing thread, NOT a new one.

[robee31]

I had a different question from the same program. Am I supposed to continue with the same thread for a different question?

[jmcilhinney]

This thread contains a chunk of code that also appears above. So are you saying that you've fixed that NullReferenceException that you were getting? I must have missed where you posted back to that other thread to say so.

If you don't get a NullReferenceException anymore, what actually does happen? Also, 'fileWriter' is obviously important here so it would be useful to see where it's created. Also, you obviously open fileWriter somewhere else so do you actually close it somewhere else too? If not then the data won't be flushed to the file until you close the app.

[robee31]

I forgot that I needed to create the file via a save as which is why there was an error when I did the enter button event to do the null method.

Public Class frmGradeBook

    Protected TextBoxCount As Integer = 3
    Protected ComboBoxCount As Integer = 2
    Private fileWriter As StreamWriter
    Private output As FileStream

    Public Enum TextBoxIndices
        txtFirstName
        txtLastName
        txtStudentId
    End Enum

    Public Enum ComboBoxIndices

        cboCourseName
        cboGrade

    End Enum

    ' Clear Text boxes once record saved.
    Public Sub ClearFormDataEntryBoxes()

        For i As Integer = 0 To Controls.Count - 1

            Dim myControl As Control = Controls(i)

            If TypeOf myControl Is TextBox Then _
            myControl.Text = ""

            If TypeOf myControl Is ComboBox Then _
            myControl.Text = Nothing

        Next

    End Sub

    Public Sub SetTextBoxValues(ByVal values() As String)

        For i As Integer = 0 To Controls.Count - 1

            Dim myControl As Control = Controls(i)

            If TypeOf myControl Is TextBox And _
                      myControl.Text = "" Then _
                      ErrorMessage1() Else 

            If TypeOf myControl Is ComboBox And _
                      myControl.Text = "" Then _
                      ErrorMessage1() Else 

            txtFirstName.Text = values(Convert.ToInt32 _
            (TextBoxIndices.txtFirstName))
            txtLastName.Text = values(Convert.ToInt32 _
            (TextBoxIndices.txtLastName))
            txtStudentId.Text = values(Convert.ToInt32 _
            (TextBoxIndices.txtStudentId))

        Next

    End Sub

   
    Private Sub btnEnter_Click(ByVal sender As System.Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnEnter.Click

        Dim values As String() = GetTextBoxValues()

        Dim record As New GradeBookDataCollector()

        Me.SetTextBoxValues(GetTextBoxValues)
        If values(TextBoxIndices.txtFirstName) <> "" Then

            Try
                Dim strFirstName As String = _
                    values(TextBoxIndices.txtFirstName)

                If strFirstName <> "" Then
                    record.strFirstName = values(TextBoxIndices.txtFirstName)
                    record.strLastName = values(TextBoxIndices.txtLastName)
                    record.strCourseName = values(ComboBoxIndices.cboCourseName)
                    record.strStudentId = values(TextBoxIndices.txtStudentId)
                    record.strGrade = values(ComboBoxIndices.cboGrade)

                    fileWriter.WriteLine( _
                    record.strFirstName.ToString & "," & record.strLastName.ToString & "," & _
                    record.strStudentId.ToString & "," & record.strCourseName.ToString & "," & _
                    record.strGrade.ToString)


                    fileWriter.Flush()


                Else
                    MessageBox.Show("Invalid First Name", "Error", _
                    MessageBoxButtons.OK, MessageBoxIcon.Error)
                End If

            Catch ex As IOException
                MessageBox.Show("Error Writing to File", "Error", _
                MessageBoxButtons.OK, MessageBoxIcon.Error)

            Catch ex As FormatException
                MessageBox.Show("Invalid Format", "Error", _
               MessageBoxButtons.OK, MessageBoxIcon.Error)

            End Try
        End If

        Me.SetTextBoxValues(GetTextBoxValues)
        Me.ClearFormDataEntryBoxes()

    End Sub
    Public Sub ErrorMessage1()

        MsgBox("Please fill in all the fields to save the record", _
        MsgBoxStyle.Exclamation, "Record Entry Incomplete")

    End Sub

    Public Function GetTextBoxValues() As String()

        Dim values(TextBoxCount) As String

        ' copy text box fields to string Array
        values(Convert.ToInt32(TextBoxIndices.txtFirstName)) = _
            txtFirstName.Text

        values(Convert.ToInt32(TextBoxIndices.txtLastName)) = _
            txtLastName.Text

        values(Convert.ToInt32(TextBoxIndices.txtStudentId)) = _
            txtStudentId.Text
        Return values

    End Function

    Private Sub btnExit_Click(ByVal sender As System.Object, _
                              ByVal e As System.EventArgs) _
                              Handles btnExit.Click

        If output IsNot Nothing Then

            Try
                fileWriter.Close()
                output.Close()

            Catch ex As IOException
                MessageBox.Show("Cannot close file", " Error", _
                MessageBoxButtons.OK, MessageBoxIcon.Error)

            End Try
        End If

        Application.Exit()

    End Sub
 Private Sub btnSaveAs_Click(ByVal sender As System.Object, _
                                ByVal e As System.EventArgs) _
                                Handles btnSaveAs.Click

        Dim fileChooser As New SaveFileDialog()
        Dim result As DialogResult = fileChooser.ShowDialog()
        Dim fileName As String

        fileChooser.CheckFileExists = False

        If result = Windows.Forms.DialogResult.Cancel Then
            Return
        End If

        fileName = fileChooser.FileName

        If fileName = "" Or fileName Is Nothing Then
            MessageBox.Show("Invalid File Name", "Error", _
            MessageBoxButtons.OK, MessageBoxIcon.Error)
        Else

            Try
                output = New FileStream( _
                   fileName, FileMode.OpenOrCreate, FileAccess.Write)

               

	
	
fileWriter = New StreamWriter(output)
:wave: 
                btnSaveAs.Enabled = False
                btnSaveAs.Enabled = True


            Catch ex As IOException

                MessageBox.Show("Error Opening File", "Error", _
                MessageBoxButtons.OK, MessageBoxIcon.Error)

            End Try
        End If

    End Sub
   

    End Sub
End Class