I want to write a global function for my whole project to use in every form. I tried creating a public module and create a public function, but when I call it to my form, it generates error.
let say my global function is about connection to the database. Then when I call it, it says that the connection property is not initialized.
In my function file, I used:
Imports System.Data.SqlClient
Public Module Connection
Dim myConnection As SqlConnection
Public Sub ConnectToDatabase()
myConnection = New SqlConnection(".............")
myConnection.Open()
End Sub
End Module
And in my form, I used:
Private Sub Form_Load(...........) Handles MyBase.Load
ConnectToDatabase() 'I call the function here
.............................开发者_开发百科..................
End Sub
And this does not work. Thanks.
I suspect this has nothing to do with the fact that this is a public module or public function and everything to do with the fact that you aren't initialising your connection correctly.
Try the following code:
Imports System.Data.SqlClient
Imports System.Data
Public Sub ConnectToSQL()
Dim con As New SqlConnection
Dim cmd As New SqlCommand
Try
con.ConnectionString = "Data Source=atisource;Initial Catalog=BillingSys;Persist Security Info=True;User ID=sa;Password=12345678"
con.Open()
Catch ex As Exception
MessageBox.Show("Error while connecting to SQL Server." & ex.Message) Finally
con.Close() 'Whether there is error or not. Close the connection.
End Try
End Sub
精彩评论