C# / VB.NET - vb.net 2013 variabili public o dim ?

Ok, quindi dovrebbe esistere la classe Form1 ... ci fai vedere tutto il contenuto di Form1.vb ?

anche la parola "avvolte" esiste, ma non credo volessi usare quella xD

comunque sposta

Dim MysqlConn As MySqlConnection

subito sotto

Public Class Form1

al di fuori degli altri metodi, tipo:

Public Class Form1

    Dim MysqlConn As MySqlConnection

    Public Function _database_connect()

        'Codice

    End Function

    'Altri metodi

End Class

certo

 

Imports MySql.Data.MySqlClient
Imports System.IO


Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        _database_connect()




    End Sub
    Public Function _database_connect()

        Dim lines() As String = My.Resources.database_config.Split(Environment.NewLine)

        Dim server As String = (lines(0).Split("=")(1))
        Dim username As String = (lines(1).Split("=")(1))
        Dim password As String = (lines(2).Split("=")(1))
        Dim database As String = (lines(3).Split("=")(1))

        Dim MysqlConn As MySqlConnection
        MysqlConn = New MySqlConnection()

        MysqlConn.ConnectionString = "server=pincopallino.it;" _
        & "user id=root;" _
        & "password=baobab;" _
        & "database=demade"

        Try
            MysqlConn.Open()
            MessageBox.Show("Connessione avvenuta con successo.")

            _estrae_rubrica_dispari()





        Catch myerror As MySqlException
            MessageBox.Show("Non è possibile connettersi al database: " & myerror.Message)
            Application.Exit()

        Finally
            MysqlConn.Dispose()
        End Try


    End Function

    Public Function _estrae_rubrica_dispari()
        Dim myadapter As New MySqlDataAdapter("select * from  dynarc_rubrica_contacts;", MysqlConn)
        Dim mydatateble As New DataTable
        myadapter.Fill(mydatateble)

        MsgBox(mydatateble.Rows(10).Item("name"))
    End Function



    Private Sub TextBox2_TextChanged(sender As Object, e As EventArgs)

    End Sub
    Private Sub Label2_Click(sender As Object, e As EventArgs) Handles Label2.Click

    End Sub

    Private Sub ContextMenuStrip1_Opening(sender As Object, e As System.ComponentModel.CancelEventArgs)

    End Sub

    Private Sub RubricaToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles RubricaToolStripMenuItem.Click
        Dim lines() As String = My.Resources.database_config.Split(Environment.NewLine)
        Dim server As String = (lines(0).Split("=")(1))
        System.Diagnostics.Process.Start("http://" & server & "/gestionale/Rubrica/")

    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged



    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Process.Start("C:\Program Files (x86)\ABBYY FineReader 10\FineReader.exe")
    End Sub
End Class

Quindi la classe c'era

Public Class Form1

Perché hai detto che sopra quella funzione c'erano solo le Imports?

Quindi

Public Class Form1
Private MysqlConn As MySqlConnection

e poi il resto, ovviamente eliminando la Dim dalla funzione

ho fatto cosi
sia mettendo dim che private

Imports MySql.Data.MySqlClient
Imports System.IO


Public Class Form1
    Dim MysqlConn As MySqlConnection
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        _database_connect()




    End Sub
    Public Function _database_connect()

        Dim lines() As String = My.Resources.database_config.Split(Environment.NewLine)

        Dim server As String = (lines(0).Split("=")(1))
        Dim username As String = (lines(1).Split("=")(1))
        Dim password As String = (lines(2).Split("=")(1))
        Dim database As String = (lines(3).Split("=")(1))


        MysqlConn = New MySqlConnection()

        MysqlConn.ConnectionString = "server=pincopallino.it;" _
        & "user id=root;" _
        & "password=baobab;" _
        & "database=demade"

        Try
            MysqlConn.Open()
            MessageBox.Show("Connessione avvenuta con successo.")

            _estrae_rubrica_dispari()





        Catch myerror As MySqlException
            MessageBox.Show("Non è possibile connettersi al database: " & myerror.Message)
            Application.Exit()

        Finally
            MysqlConn.Dispose()
        End Try


    End Function

    Public Function _estrae_rubrica_dispari()
        Dim myadapter As New MySqlDataAdapter("select * from  dynarc_rubrica_contacts;", MysqlConn)
        Dim mydatateble As New DataTable
        myadapter.Fill(mydatateble)

        MsgBox(mydatateble.Rows(10).Item("name"))
    End Function



    Private Sub TextBox2_TextChanged(sender As Object, e As EventArgs)

    End Sub
    Private Sub Label2_Click(sender As Object, e As EventArgs) Handles Label2.Click

    End Sub

    Private Sub ContextMenuStrip1_Opening(sender As Object, e As System.ComponentModel.CancelEventArgs)

    End Sub

    Private Sub RubricaToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles RubricaToolStripMenuItem.Click
        Dim lines() As String = My.Resources.database_config.Split(Environment.NewLine)
        Dim server As String = (lines(0).Split("=")(1))
        System.Diagnostics.Process.Start("http://" & server & "/gestionale/Rubrica/")

    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged



    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Process.Start("C:\Program Files (x86)\ABBYY FineReader 10\FineReader.exe")
    End Sub
End Class

ma mi da errore e non si connette , (calcola che con il software per amministrare il db ci entro e ci razzolo tranquillamente )

Warning    1    Function '_database_connect' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.    \Form1.vb    50    5    gestionale-web


Warning    2    Function '_estrae_rubrica_dispari' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.    \Form1.vb    58    5    gestionale-web

Intanto le funzioni indicate non restituiscono valori ... a questo punto perché sono funzioni ?

mi dava errore perche , avevo cambiato alcune cose sul db
scusate

adesso mi da un altro errore ma provo a risolvere , se no non spremo mai il mio povero gulliver

se non ci riesco continuo a stressarvi grazie ancora a tutti