Serial Port GPS Layer

This sample demonstrates how to use the SerialPortGpsCoordinateWatcher to search for a serial port with a connected GPS receiver and to show the reported location on a map.

XAML

<UserControl x:Class="ArcGISWPFSDK.SerialPortGpsLayer"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:esri="http://schemas.esri.com/arcgis/client/2009"
             Unloaded="UserControl_Unloaded">
    <Grid>
        <Grid.Resources>
            <LinearGradientBrush x:Key="PanelGradient" EndPoint="0.5,1" StartPoint="0.5,0">
                <LinearGradientBrush.RelativeTransform>
                    <TransformGroup>
                        <ScaleTransform CenterY="0.5" CenterX="0.5"/>
                        <SkewTransform CenterY="0.5" CenterX="0.5"/>
                        <RotateTransform Angle="176" CenterY="0.5" CenterX="0.5"/>
                        <TranslateTransform/>
                    </TransformGroup>
                </LinearGradientBrush.RelativeTransform>
                <GradientStop Color="#FF145787" Offset="0.16"/>
                <GradientStop Color="#FF3D7FAC" Offset="0.502"/>
                <GradientStop Color="#FF88C5EF" Offset="0.984"/>
            </LinearGradientBrush>

        </Grid.Resources>
        <esri:Map Extent="-13046586.9363318,4036013.64823107,-13045676.4100906,4036832.85611">
            <esri:ArcGISTiledMapServiceLayer ID="arcGISTiledMapServiceLayer" Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer" />
            <esri:GpsLayer x:Name="gpsLayer"/>
        </esri:Map>
        <Border Background="#995C90B2" BorderThickness="1" CornerRadius="5"
            HorizontalAlignment="Center"  VerticalAlignment="Center"
            Visibility="{Binding ElementName=txtInfo, Path=Visibility}"
            Margin="20" Padding="5" BorderBrush="Black">
            <TextBlock x:Name="txtInfo" Visibility="Collapsed" Text="Looking for GPS device..."/>
        </Border>

        <Grid HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10,10,10,0" >
            <Rectangle Fill="{StaticResource PanelGradient}" Stroke="Gray"  RadiusX="10" RadiusY="10" Margin="0,0,0,5">
                <Rectangle.Effect>
                    <DropShadowEffect/>
                </Rectangle.Effect>
            </Rectangle>
            <Rectangle Fill="#DDFFFFFF" Stroke="DarkGray" RadiusX="5" RadiusY="5" Margin="5,5,5,10" />
            <StackPanel>
            <TextBlock x:Name="Instructions" Text="Click Start to search for a GPS device attached to a serial port and click Stop to cancel the search." 
                       Width="200" TextAlignment="Left" Margin="15,15,15,5" TextWrapping="Wrap" Foreground="Black" />
                <Button Width="100" Margin="15,5,15,20" Content="Start"  x:Name="btnGps"  Click="btnGps_Click"/>
            </StackPanel>
        </Grid>

    </Grid>
</UserControl>

C#

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Device.Location;
using System.Threading;

namespace ArcGISWPFSDK
{
    /// <summary>
    /// Interaction logic for SerialPortGpsLayer.xaml
    /// </summary>
    public partial class SerialPortGpsLayer : UserControl
    {
        IGeoPositionWatcher<GeoCoordinate> _locationWatcher;
        bool _isStarted;

        public SerialPortGpsLayer()
        {
            InitializeComponent();
            Application.Current.Exit += new ExitEventHandler(Current_Exit);
        }

        private void CreateGpsWatcher(List<string> serialPorts)
        {
            if (!this.Dispatcher.CheckAccess())
            {
                // Invoke in calling thread
                this.Dispatcher.Invoke((ThreadStart)delegate() { CreateGpsWatcher(serialPorts); });
                return;
            }
            btnGps.IsEnabled = true;
            if (serialPorts == null)
            {
                txtInfo.Text = "GPS device not found";
                return;
            }

            // Hide searching text 
            txtInfo.Visibility = System.Windows.Visibility.Collapsed;

            _locationWatcher = new ESRI.ArcGIS.Client.Local.Gps.SerialPortGpsCoordinateWatcher() { PortName = serialPorts[0] };
            gpsLayer.GeoPositionWatcher = _locationWatcher;
        }

        void Current_Exit(object sender, ExitEventArgs e)
        {
            CleanUp();
        }

        private void UserControl_Unloaded(object sender, RoutedEventArgs e)
        {
            CleanUp();
        }

        private void CleanUp()
        {
            if (_locationWatcher == null)
                return;
            //Cleanup IGeoPositionWatcher resource
            IDisposable gpsWatcher = _locationWatcher as IDisposable;
            if (gpsWatcher != null)
                gpsWatcher.Dispose();
        }

        private void btnGps_Click(object sender, RoutedEventArgs e)
        {

            txtInfo.Visibility = System.Windows.Visibility.Visible;
            if (_isStarted)
            {
                CleanUp();
                btnGps.IsEnabled = true;
                btnGps.Content = "Start";
                txtInfo.Visibility = System.Windows.Visibility.Collapsed;
                _isStarted = false;
                return;
            }

            _isStarted = true;
            btnGps.Content = "Stop";
            txtInfo.Text = "Looking for GPS device...";
            ThreadPool.QueueUserWorkItem((WaitCallback)delegate
            {
                // Search for GPS port
                CreateGpsWatcher(ESRI.ArcGIS.Client.Local.Gps.SerialPortGpsCoordinateWatcher.FindGPSEnabledPort(1));
            });
        }
    }
}

VB.NET

Imports System.Collections.Generic
Imports System.Windows
Imports System.Windows.Controls
Imports System.Device.Location
Imports System.Threading

''' <summary>
''' Interaction logic for SerialPortGpsLayer.xaml
''' </summary>
Namespace ArcGISWPFSDK
    Partial Public Class SerialPortGpsLayer
        Inherits UserControl
        Private _locationWatcher As IGeoPositionWatcher(Of GeoCoordinate)
        Private _isStarted As Boolean

        Public Sub New()
            InitializeComponent()
            AddHandler Application.Current.[Exit], New ExitEventHandler(AddressOf Current_Exit)            
        End Sub

        Private Sub CreateGpsWatcher(serialPorts As List(Of String))
            If Not Me.Dispatcher.CheckAccess() Then
                'Invoke in calling thread
                Me.Dispatcher.Invoke(DirectCast(Sub() CreateGpsWatcher(serialPorts), ThreadStart))
                Return
            End If
            btnGps.IsEnabled = True
            If serialPorts Is Nothing Then
                txtInfo.Text = "GPS device not found"
                Return
            End If

            'Hide searching text 
            txtInfo.Visibility = System.Windows.Visibility.Collapsed

            _locationWatcher = New ESRI.ArcGIS.Client.Local.Gps.SerialPortGpsCoordinateWatcher() With { _
             .PortName = serialPorts(0) _
            }
            gpsLayer.GeoPositionWatcher = _locationWatcher
        End Sub

        Private Sub Current_Exit(sender As Object, e As ExitEventArgs)
            CleanUp()
        End Sub

        Private Sub UserControl_Unloaded(sender As Object, e As RoutedEventArgs)
            CleanUp()
        End Sub

        Private Sub CleanUp()
            If _locationWatcher Is Nothing Then
                Return
            End If
            'Cleanup GpsCoordinateWatcher resource
            Dim gpsWatcher As IDisposable = TryCast(_locationWatcher, IDisposable)
            If gpsWatcher IsNot Nothing Then
                gpsWatcher.Dispose()
            End If
        End Sub

        Private Sub btnGps_Click(sender As Object, e As RoutedEventArgs)

            txtInfo.Visibility = System.Windows.Visibility.Visible
            If _isStarted Then
                CleanUp()
                btnGps.IsEnabled = True
                btnGps.Content = "Start"
                txtInfo.Visibility = System.Windows.Visibility.Collapsed
                _isStarted = False
                Return
            End If

            _isStarted = True
            btnGps.Content = "Stop"
            txtInfo.Text = "Looking for GPS device..."
            'Search for GPS port
            ThreadPool.QueueUserWorkItem(DirectCast(Sub() CreateGpsWatcher(ESRI.ArcGIS.Client.Local.Gps.SerialPortGpsCoordinateWatcher.FindGPSEnabledPort(1)), WaitCallback))
        End Sub
    End Class
End Namespace