GuruxSNMP component

This guide shows how to use Gurux SNMP component (GXSNMP) in the Visual Basic environment. The development version of GXSNMP comes with a Visual Basic example. Source code is available at sourceforge.net

Adding GXSNMP component to the project

Start Visual Basic
Open the project where you want to add the GXSNMP component, or create a new one
Select Components from the Project menu
Select the GXSNMP component and click OK to finish

Using components with Visual Basic

You can either drag the component to the form, or create it dynamically.

Creating component dynamically

To create component in runtime, select References in the Project menu. The dialog shows available components, select the one(s) to use (in this case Gurux SNMP component). Click OK to finish. The following example shows how to create a GXSNMP component.

Dim WithEvents GXSNMP1 As GXSNMP
'Create new component
Set GXSNMP1= New GXSNMP

Note: WithEvents means that component can receive asynchronous calls.

Setting Media Properties

You can either select appropriate settings in the Properties dialog or edit the settings programmatically.

'Set server port and TCP/IP address.
GXSNMP1.SNMPPort = 161
GXSNMP1.HostName = "Localhost"
GXSNMP1.Connect
Dim pack As New GXSNMPPacket
pack.Command = GX_SNMP_COMMAND_GET
pack.OID = "1.3.6.1.2.1.1.1.0"
GXSNMP1.Send pack, "localhost"

Sending and receiving packets

All data is sent asynchronously. Response is received as a Received event message.

Receiving event messages

Because the GXSMS1 variable was introduced as the WithEvents type, an incoming event message from the system can be received very easily. The following example shows how to create a handler for the Received method.

Select GXSNMP1 in the left menu above the code window. In the right menu, select the event message, on which you want to make the handler (OnReceived). Code window then displays following:

Private Sub GXSNMP1_OnReceived(var As Variant, ByVal SenderInfo As String)
 Dim pack As GXSNMPPacket
    Set pack = data
    Dim pos As Integer
    For pos = 0 To pack.DataItems.Count - 1
    'Show received data.
        MsgBox pack.DataItems(pos).OID & ": "& pack.DataItems(pos).Data
    Next
End Sub

Now create handler for OnError event.

Error Handling

It's very important to consider error handling when sending and receiving data. The connection can drop down, or something else unexpected may happen. If something unwanted happens, Gurux SNMP component returns error.The following example shows how to handle errors in Visual Basic.

Sub SendData(Data As Variant)
On Error GoTo GXErrHandler
    'Send Data
    GXSNMP1.Send Data
    Exit Sub
GXErrHandler:
    'Show occurred error
    MsgBox Err.Description
End Sub

Using the components from development environment

Using from .NET | Using from Visual Basic | Using from C++