[Visual Basic .NET]
    Sub GeocodeAddressClientAgainstServer()
        Dim connectionProperties = New PropertySet
        connectionProperties.SetProperty("Machine", "AGSServer")

        Dim serverConnectionFactory As IAGSServerConnectionFactory = New AGSServerConnectionFactory
        Dim agsServerConnection As IAGSServerConnection = serverConnectionFactory.Open(connectionProperties, 0)

        Dim serverObjectNames As IAGSEnumServerObjectName = agsServerConnection.ServerObjectNames
        serverObjectNames.Reset()

        ' Get the GeocodeServer service information
        Dim name As IName
        Dim geocodeServer As IGeocodeServer
        Dim serverObject As IAGSServerObject
        Dim serverObjectName As IAGSServerObjectName = serverObjectNames.Next()

        While Not serverObjectName Is Nothing
            ' UnitedStates is a locator published to ArcGIS Server in a Geocode folder
            If serverObjectName.Name = "Geocode/UnitedStates" And serverObjectName.Type = "GeocodeServer" Then
                name = serverObjectName
                serverObject = name.Open()
                If Not serverObject Is Nothing Then
                    geocodeServer = serverObject
                    Exit While
                End If
            End If
            serverObjectName = serverObjectNames.Next()
        End While

        ' Set the Address Properties and Geocode the address
        Dim fields As IFields = geocodeServer.GetAddressFields()
        Dim addressProperties As IPropertySet = New PropertySet
        addressProperties.SetProperty(fields.Field(0).Name, "9300 Cherry Ave")
        addressProperties.SetProperty(fields.Field(1).Name, "Fontana")
        addressProperties.SetProperty(fields.Field(2).Name, "CA")
        addressProperties.SetProperty(fields.Field(3).Name, "92335")
        Dim addressResultProperties As IPropertySet = geocodeServer.GeocodeAddress(addressProperties, Nothing)
    End Sub

[C#]

        public void GeocodeAddressClient()
        {
            IPropertySet connectionProperties = new PropertySet();
            connectionProperties.SetProperty("Machine", "AGSServer");

            // Create a connection to the ArcGIS Server
            Type t = Type.GetTypeFromProgID("esriGISClient.AGSServerConnectionFactory");
            System.Object obj = Activator.CreateInstance(t);
            IAGSServerConnectionFactory serverConnectionFactory = obj as AGSServerConnectionFactory;
            IAGSServerConnection agsServerConnection = serverConnectionFactory.Open(connectionProperties, 0);
            IAGSEnumServerObjectName serverObjectNames = agsServerConnection.ServerObjectNames;
            serverObjectNames.Reset();

            // Get the GeocodeServer service information
            IName name;
            IGeocodeServer geocodeServer = null;
            IAGSServerObject serverObject = null;
            IAGSServerObjectName serverObjectName = serverObjectNames.Next();
            while (serverObjectName != null)
            {
                // California is a locator published to ArcGIS Server in a Geocode folder
                if (serverObjectName.Name == "Geocode/California" && serverObjectName.Type == "GeocodeServer")
                {
                    name = serverObjectName as IName;
                    serverObject = name.Open() as IAGSServerObject;
                    if (serverObject as IGeocodeServer != null)
                    {
                        geocodeServer = serverObject as IGeocodeServer;
                        break;
                    }
                }
                serverObjectName = serverObjectNames.Next();
            }

            // Set up the address properties and geocode the address
            IFields fields = geocodeServer.GetAddressFields();
            IPropertySet addressProperties = new PropertySetClass();
            addressProperties.SetProperty(fields.get_Field(0).Name, "9300 Cherry Ave");
            addressProperties.SetProperty(fields.get_Field(1).Name, "Fontana");
            addressProperties.SetProperty(fields.get_Field(2).Name, "CA");
            addressProperties.SetProperty(fields.get_Field(3).Name, "92335");

            IPropertySet addressResultProperties = geocodeServer.GeocodeAddress(addressProperties, null);
        }