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Windows phone 8 学习笔记(8) 定位地图导航(转)

Windows phone 8 已经不使用自家的bing地图,新地图控件可以指定制图模式、视图等。bing地图的定位误差比较大,在模拟器中测试新地图貌似比较理想。本节主要讲解下位置服务以及新地图控件的使用。

快速导航:
一、定位服务
二、地图和导航

一、定位服务

通过手机定位服务可以开发利用手机地理位置的应用。我们可以通过应用监视手机行踪,配合地图使用可以用于导航等。定位服务可以及时取得手机地理位置,也可以持续跟踪手机移动,还可以在后台运行。

1. 立即获取当前位置

我们可以通过一次操作获取当前位置,下面的代码演示了实现的方法。

[C#]

private async void OneShotLocation_Click(object sender, RoutedEventArgs e)

{

//地理位置访问服务

Geolocator geolocator = new Geolocator();

//定义精度,米为单位

geolocator.DesiredAccuracyInMeters = 1;

try

{

//开始获取当前位置的经纬度

Geoposition geoposition = await geolocator.GetGeopositionAsync();

LatitudeTextBlock.Text = "经度:" + geoposition.Coordinate.Latitude.ToString("0.00");

LongitudeTextBlock.Text = "纬度:" + geoposition.Coordinate.Longitude.ToString("0.00");

}

catch (Exception ex)

{

if ((uint)ex.HResult == 0x80004004)

{

StatusTextBlock.Text = "系统设置关闭了位置服务.";

}

}

}

2. 持续跟踪位置信息

如果开启持续跟踪手机位置,当手机移动距离超出设定距离时,就会触发位置改变事件,这个时候我们就可以通过环境信息计算出手机的行动轨迹,速度方向等。下面演示了如何持续跟踪。

[C#]

Geolocator geolocator = null;

bool tracking = false;

private void TrackLocation_Click(object sender, RoutedEventArgs e)

{

if (!tracking)

{

//地理位置访问服务

geolocator = new Geolocator();

//精度级别

geolocator.DesiredAccuracy = PositionAccuracy.High;

//超过多少米引发位置改变事件

geolocator.MovementThreshold = 100;

//功能状态改变时

geolocator.StatusChanged += geolocator_StatusChanged;

//位置改变时

geolocator.PositionChanged += geolocator_PositionChanged;

tracking = true;

TrackLocationButton.Content = "停止跟踪";

}

else

{

geolocator.PositionChanged -= geolocator_PositionChanged;

geolocator.StatusChanged -= geolocator_StatusChanged;

geolocator = null;

tracking = false;

TrackLocationButton.Content = "跟踪位置";

StatusTextBlock.Text = "停止";

}

}

void geolocator_StatusChanged(Geolocator sender, StatusChangedEventArgs args)

{

string status = "";

switch (args.Status)

{

case PositionStatus.Disabled:

status = "位置服务设置被禁用";

break;

case PositionStatus.Initializing:

status = "正在初始化";

break;

case PositionStatus.NoData:

status = "无数据";

break;

case PositionStatus.Ready:

status = "已准备";

break;

case PositionStatus.NotAvailable:

status = "无法使用";

break;

case PositionStatus.NotInitialized:

break;

}

Dispatcher.BeginInvoke(() =>

{

StatusTextBlock.Text = status;

});

}

void geolocator_PositionChanged(Geolocator sender, PositionChangedEventArgs args)

{

Dispatcher.BeginInvoke(() =>

{

LatitudeTextBlock.Text = "经度:" + args.Position.Coordinate.Latitude.ToString("0.00");

LongitudeTextBlock.Text = "纬度:" + args.Position.Coordinate.Longitude.ToString("0.00");

});

}

3. 在后台持续跟踪

位置跟踪可以作为服务在后台运行,这个时候我们不需要更新UI,为了使我们的应用可以作为服务运行,我们需要右键打开清单文件,选择用XML文本编辑器的方式,替换DefaultTask节点为如下信息:

[XML]

      <DefaultTask Name="_default" NavigationPage="MainPage.xaml">        <BackgroundExecution>          <ExecutionType  Name="LocationTracking" />        </BackgroundExecution>      </DefaultTask>

然后我们需要注册RunningInBackground事件,打开App.xaml添加事件Application_RunningInBackground,代码如下:

[XAML]

        <!--处理应用程序的生存期事件所需的对象-->        <shell:PhoneApplicationService            Launching="Application_Launching" Closing="Application_Closing"            Activated="Application_Activated" Deactivated="Application_Deactivated"            RunningInBackground="Application_RunningInBackground"/>

在App.xaml.cs中添加静态变量RunningInBackground和Geolocator,当Application_RunningInBackground事件时RunningInBackground为true,当Application_Activated事件时,RunningInBackground为false。代码如下:

[C#]

//确定应用是否在后台运行public static bool RunningInBackground { get; set; }//提供对当前地理位置的访问public static Geolocator Geolocator { get; set; }// 激活应用程序(置于前台)时执行的代码// 此代码在首次启动应用程序时不执行private void Application_Activated(object sender, ActivatedEventArgs e){    RunningInBackground = false;}private void Application_RunningInBackground(object sender, RunningInBackgroundEventArgs args){    RunningInBackground = true;}

在mainpage中添加如下代码:

[C#]

protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e){    if (App.Geolocator == null)    {        App.Geolocator = new Geolocator();        App.Geolocator.DesiredAccuracy = PositionAccuracy.High;        App.Geolocator.MovementThreshold = 100;        App.Geolocator.PositionChanged += geolocator_PositionChanged;    }}void geolocator_PositionChanged(Geolocator sender, PositionChangedEventArgs args){    if (!App.RunningInBackground)    {        Dispatcher.BeginInvoke(() =>        {            LatitudeTextBlock.Text = "经度:" + args.Position.Coordinate.Latitude.ToString("0.00");            LongitudeTextBlock.Text = "纬度:" + args.Position.Coordinate.Longitude.ToString("0.00");        });    }    else    {        Microsoft.Phone.Shell.ShellToast toast = new Microsoft.Phone.Shell.ShellToast();        toast.Content = args.Position.Coordinate.Latitude.ToString("0.00") + "," + args.Position.Coordinate.Longitude.ToString("0.00");        toast.Title = "位置:";        toast.NavigationUri = new Uri("/Page1.xaml", UriKind.Relative);        toast.Show();    }}

二、地图和导航

要用到新地图控件,需要先注册,在phone:PhoneApplicationPage注册标识。

[XAML]

xmlns:maps="clr-namespace:Microsoft.Phone.Maps.Controls;assembly=Microsoft.Phone.Maps"    
1.引入地图控件

在XAML中添加如下代码即可引入控件。我们看到Center就是指当前地图中心点的经纬度;ZoomLevel就是缩放级别; LandmarksEnabled 属性设置为 true 以在 Map 控件上显示地标; PedestrianFeaturesEnabled 设置为 true,以显示步行街构造。

[XAML]

        <!--ContentPanel - 在此处放置其他内容-->        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">            <!--地图控件-->            <maps:Map x:Name="MyMap" Center="30.5473, 114.2922" ZoomLevel="10" LandmarksEnabled="true" PedestrianFeaturesEnabled="true" />            <Button Foreground="Red" Content="指定位置" HorizontalAlignment="Left" Margin="295,530,0,0" VerticalAlignment="Top" Click="Button_Click_1" Width="151"/>            <Button Foreground="Red" Content="制图模式" HorizontalAlignment="Left" Margin="10,530,0,0" VerticalAlignment="Top" Click="Button_Click_2"/>            <Button Foreground="Red" Content="颜色模式" HorizontalAlignment="Left" Margin="134,530,0,0" VerticalAlignment="Top" Click="Button_Click_3"/>            <Button Foreground="Red" Content="我的位置" HorizontalAlignment="Left" Margin="10,602,0,0" VerticalAlignment="Top" Click="Button_Click_4"/>        </Grid>
2.设置制图模式

在制图模式中有四个选项,分别如下:
Road:显示正常的默认二维地图。
Aerial:显示航测图。
Hybrid:显示与道路和标签重叠的地图的“航测”视图。
Terrain:为显示的高地和水域构造(例如高山和河流)显示自然地形图像。

下面看看如何切换。

[C#]

//切换制图模式private void Button_Click_2(object sender, RoutedEventArgs e){    switch (MyMap.CartographicMode)    {        case MapCartographicMode.Aerial:            MyMap.CartographicMode = MapCartographicMode.Hybrid;            break;        case MapCartographicMode.Hybrid:            MyMap.CartographicMode = MapCartographicMode.Road;            break;        case MapCartographicMode.Road:            MyMap.CartographicMode = MapCartographicMode.Terrain;            break;        case MapCartographicMode.Terrain:            MyMap.CartographicMode = MapCartographicMode.Aerial;            break;    }}
3.设置颜色模式

颜色分为明和暗两种,我们看看如何实现。

[C#]

//切换颜色模式private void Button_Click_3(object sender, RoutedEventArgs e){    if (MyMap.ColorMode == MapColorMode.Light)        MyMap.ColorMode = MapColorMode.Dark;    else MyMap.ColorMode = MapColorMode.Light;}
4.指定新视角位置

我们可以通过编程方式切换视角位置到新的经纬度,并可以指定切换时的过渡效果,这里指定的是抛物线的方式。

[C#]

private void Button_Click_1(object sender, RoutedEventArgs e){    //以抛物线的方式,把视角定位到光谷软件园中心湖上空。    MyMap.SetView(new GeoCoordinate(30.476724, 114.406563), 16, MapAnimationKind.Parabolic);}
5.定位我的位置并标记

把地图定位到我的当前位置。这个时候就需要借助定位的功能,通过定位功能获取到的经纬度实例类型不一样,需要预先做一个转换。转换类CoordinateConverter如下。

[C#]

public static class CoordinateConverter{    /// <summary>    /// 把定位位置转换为地图位置    /// </summary>    /// <param name="geocoordinate"></param>    /// <returns></returns>    public static GeoCoordinate ConvertGeocoordinate(Geocoordinate geocoordinate)    {        return new GeoCoordinate            (            geocoordinate.Latitude,            geocoordinate.Longitude,            geocoordinate.Altitude ?? Double.NaN,            geocoordinate.Accuracy,            geocoordinate.AltitudeAccuracy ?? Double.NaN,            geocoordinate.Speed ?? Double.NaN,            geocoordinate.Heading ?? Double.NaN            );    }}

然后,我们需要在地图上画一个小正方形标记我的当前位置,并把地图定位到这里。

[C#]

//添加其他控件到地图,标识我的当前位置private async void Button_Click_4(object sender, RoutedEventArgs e){    //获取我的地理位置    Geolocator myGeolocator = new Geolocator();    //精度    myGeolocator.DesiredAccuracyInMeters = 1;    Geoposition myGeoposition = await myGeolocator.GetGeopositionAsync();    Geocoordinate myGeocoordinate = myGeoposition.Coordinate;    //转换经纬度GeoCoordinate    GeoCoordinate myGeoCoordinate =  CoordinateConverter.ConvertGeocoordinate(myGeocoordinate);    //MessageBox.Show(myGeoCoordinate.ToString());    //定位地图到我的位置    MyMap.SetView(myGeoCoordinate, 16, MapAnimationKind.Parabolic);    //画一个正方形,然后渲染在地图的我的当前位置上    Rectangle MyRectangle = new Rectangle();    MyRectangle.Fill = new SolidColorBrush(Colors.Black);    MyRectangle.Height = 20;    MyRectangle.Width = 20;    MapOverlay MyOverlay = new MapOverlay();    MyOverlay.Content = MyRectangle;    MyOverlay.GeoCoordinate = myGeoCoordinate;    MyOverlay.PositionOrigin = new Point(0, 0.5);    MapLayer MyLayer = new MapLayer();    MyLayer.Add(MyOverlay);    MyMap.Layers.Add(MyLayer);}
6.获取行车路线

我们还可以通过定位和地图实现导航的功能,下面演示了,从我的当前位置(光谷软件园)到指定的位置(光谷创业街)如何行车。

[XAML]

    <phone:PhoneApplicationPage.Resources>        <DataTemplate x:Key="RouteListTemplate">            <TextBlock Text="{Binding}" FontSize="{StaticResource PhoneFontSizeMedium}" Margin="5,5,0,0"/>        </DataTemplate>    </phone:PhoneApplicationPage.Resources>    <!--LayoutRoot 是包含所有页面内容的根网格-->        <Grid x:Name="LayoutRoot" Background="Transparent">            <Grid.RowDefinitions>                <RowDefinition Height="auto"/>                <RowDefinition Height="*"/>                <RowDefinition Height="auto"/>                <RowDefinition Height="*"/>            </Grid.RowDefinitions>            <TextBlock Text="地图导航" Grid.Row="0" FontSize="{StaticResource PhoneFontSizeLarge}" Margin="0,0,0,20"/>            <maps:Map x:Name="MyMap" Grid.Row="1" Center="30.476724, 114.406563" ZoomLevel="13"/>            <TextBlock Text="驾车路线" Grid.Row="2" FontSize="{StaticResource PhoneFontSizeLarge}" Margin="0,10,0,20"/>            <phone:LongListSelector x:Name="RouteLLS" Grid.Row="3" Background="Transparent" ItemTemplate="{StaticResource RouteListTemplate}" LayoutMode="List"       IsGroupingEnabled="False"/>    </Grid>

[C#]

    public partial class Page1 : PhoneApplicationPage    {        public Page1()        {            InitializeComponent();            this.GetCoordinates();        }        RouteQuery MyQuery = null;        GeocodeQuery Mygeocodequery = null;        List<GeoCoordinate> MyCoordinates = new List<GeoCoordinate>();        private async void GetCoordinates()        {            Geolocator MyGeolocator = new Geolocator();            MyGeolocator.DesiredAccuracyInMeters = 5;            Geoposition MyGeoPosition = null;            try            {                MyGeoPosition = await MyGeolocator.GetGeopositionAsync(TimeSpan.FromMinutes(1), TimeSpan.FromSeconds(10));            }            catch (UnauthorizedAccessException)            {                MessageBox.Show("系统设置已关闭位置服务。");            }            catch (Exception ex)            {            }            MyCoordinates.Add(new GeoCoordinate(MyGeoPosition.Coordinate.Latitude, MyGeoPosition.Coordinate.Longitude));            Mygeocodequery = new GeocodeQuery();            Mygeocodequery.SearchTerm = "光谷创业街";            Mygeocodequery.GeoCoordinate = new GeoCoordinate(MyGeoPosition.Coordinate.Latitude, MyGeoPosition.Coordinate.Longitude);            Mygeocodequery.QueryCompleted += Mygeocodequery_QueryCompleted;            Mygeocodequery.QueryAsync();        }        void Mygeocodequery_QueryCompleted(object sender, QueryCompletedEventArgs<IList<MapLocation>> e)        {            if (e.Error == null)            {                MyQuery = new RouteQuery();                MyCoordinates.Add(e.Result[0].GeoCoordinate);                MyQuery.Waypoints = MyCoordinates;                MyQuery.QueryCompleted += MyQuery_QueryCompleted;                MyQuery.QueryAsync();                Mygeocodequery.Dispose();            }        }        void MyQuery_QueryCompleted(object sender, QueryCompletedEventArgs<Route> e)        {            if (e.Error == null)            {                //获取具体的行程路线                Route MyRoute = e.Result;                MapRoute MyMapRoute = new MapRoute(MyRoute);                MyMap.AddRoute(MyMapRoute);                List<string> RouteList = new List<string>();                foreach (RouteLeg leg in MyRoute.Legs)                {                    foreach (RouteManeuver maneuver in leg.Maneuvers)                    {                        RouteList.Add(maneuver.InstructionText);                    }                }                RouteLLS.ItemsSource = RouteList;                MyQuery.Dispose();            }        }    }