Call vb class to form load - vb.net

Question

I am trying to move the following code to the VB Class, let says DataAccess.vb and then call the created VB Class using button click event, but I don't know how to do that. Does anyone here would help me to find out how to do that.
This is the code that I need to move to VB Class.
Sub LoadData()
Try
LblInvId.Text = Me._InvID.Substring(57, 27).Trim
Dim InvID As String = LblInvId.Text.Trim
Using cn As New SqlClient.SqlConnection(DatabaseConnectionForPDA.DatabaseConnection.CONNECT_RO_FOR_HMCS)
cn.Open()
Dim sql As String = String.Empty
sql &= " SELECT T1.InvID "
sql &= " , T1.ItemID"
sql &= " , T2.ItemRevNo"
sql &= " , T1.RefNo2"
sql &= " , SUM(T1.Qty) AS Qty"
sql &= " , COUNT(*) AS CRow"
sql &= " FROM [HMCS].dbo.R_Warehouse T1 "
sql &= " INNER JOIN [HMCS].dbo.M_Item T2 "
sql &= " ON T1.ItemID = T2.ItemID "
sql &= " WHERE T1.InvDate = [HMCS].dbo.f_GetInvDate() "
sql &= " AND (RTRIM(T1.InvID) = #InvID OR RTRIM(T1.RefNo2) = #InvID)"
sql &= " GROUP BY T1.InvID, T1.ItemID, T2.ItemRevNo, T1.RefNo2"
Using cmd As New SqlClient.SqlCommand(sql, cn)
cmd.Parameters.AddWithValue("#InvID", InvID)
Using dr As SqlDataReader = cmd.ExecuteReader()
Do Until dr.Read = False
LblItmNo.Text = dr("ItemID")
LblItmRevNo.Text = dr("ItemRevNo")
LblRevNo2.Text = dr("RefNo2")
LblQty.Text = dr("Qty")
LblRow.Text = dr("CRow")
Exit Do
Loop
End Using
End Using
cn.Close()
If LblRow.Text = "" Then
err.Display("在庫レコードが見つかりません", "Error Message")
Me.Close()
End If
End Using
Catch ex As Exception
err.Display(ex.Message, "Error Message")
End Try
End Sub

Answer 1

You can achieve that by creating an OnClick Event for the Button and referring to your function on the code side.
DataAccess.LoadData()
You will also need to pass the Textfields to the function since it will not know what for example LblInvId is in the separate class.
DataAccess.LoadData(LblInvId,...)

Answer 2

By assuming that you meant calling LoadData() from an event handler in another class, you have at least 2 options. One, making LoadData() shared then calling it as DataAccess.LoadData() in your click event handler. Two, creating an instance of DataAccess to access LoadData(). In your event handler:
Dim da As New DataAccess()
da.LoadData()