GuruxNet component

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

Adding GXNet component to the project

Start Visual Basic
Open the project where you want to add the GXNet component, or create the new one
Select Components from the Project menu
Select the GXNet 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 Network component). Click OK to finish. The following example shows how to create a GXNet component.

Dim WithEvents GXNet1 As GXNet
'Create new component
Set GXNet1= New GXNet

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.
GXNet1.HostPort = 1234
GXNet1.HostName = "Localhost"
GXNet1.connect

Sending and receiving packets

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

Receiving event messages

Because the GXGPRS1 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 GXNet1 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 GXNet1_OnReceived(var As Variant, ByVal SenderInfo As String)
	'Add code here
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 Network 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
	GXNet1.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++ | Parameter Types