Windows Phone中Map控件由浅及深

鄙人所在的OMG团队在高级软件工程课程团队项目，负责Microsoft的Academic Search在手机WP7.1上客户端的开发。现已进入十天的beta版本开发阶段。这两天用到了Map控件，我想结合自己dev的经历，对Map控件稍作介绍。

〖PS：我们是来自中国科大各个专业（数学、EE、CS）的大四学生，六个人，欢迎各位看官来我们的团队技术博客指点一二：http://www.cnblogs.com/OMG-Team/〗

 

Map控件，是基于Microsoft的Bing map的地图控件，在WP7能很好的使用bing map实现地图的呈现，缩放，标注和定位等功能。

首先，介绍一下Map控件的简单应用吧。

在使用Map控件之前，我们必须先注册地图获得一个Register Key才能够使用bing map，注册地址：https://www.bingmapsportal.com 。新建一个Sliverlight for Windows Phone的工程，就可以开始练习使用Map控件了。在xaml里添加一个地图控件

在.cs文件里添加register key的代码（或者不使用Binding直接写在xaml中也行）

 

<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">  
     <my:Map Height="623" HorizontalAlignment="Left" 
                    CredentialsProvider="{Binding CredentialsProvider}" 
                    Margin="12,-22,0,0" Name="map1"

                    VerticalAlignment="Top" Width="425"/> 
</Grid>

note：应该添加一个namespace：

using Microsoft.Phone.Controls.Maps; 

namespace MapExample 
{ 
      public partial class MainPage : PhoneApplicationPage 
     { 
          const String BingMapsId = "Al7xKT8k0tvRNSCTc0uQs6AM1k-gREOdyigcbbbL4z932ynL42ySQuht1Ur6hpLI"; 
          private readonly CredentialsProvider credentialsProvider = new ApplicationIdCredentialsProvider(BingMapsId); 
          public CredentialsProvider CredentialsProvider 
          { 
               get { return credentialsProvider; } 
          } 
          // Constructor 
          public MainPage() 
          { 
              InitializeComponent(); 
           } 
      } 
}

这样就可以运行一个最基本的map控件了。

下面，我们看看如何设置map的中心点以及Zoomlevel以及显示模式。

这个很简单只需要改变Center、 Zoomlevel和Map.Mode这几个属性的值，同样可以在xaml直接设置，或者在.cs文件里设置，当然，更高级点的用法就是对Center，zoomlevel等进行Binding了。

Map控件还有很多其他的属性，比如ZoomBarVisibility，ScaleVisibility，LogoVisibility等，这些都可以简单的进行设置或者通过Binding技术实现动态的属性值的改变。
然而，Map控件还提供添加标注，添加图片，绘制多边形，多边线等功能。

下面讲讲如何添加一个标记吧。

首先，我们可以在MainPage()里建立并初始化一个标记（ 记得添加namespace： using System.Device.Location; )

Pushpin pin = new Pushpin(); 
pin.Location = new GeoCoordinate(30, 120); 
pin.Background = new SolidColorBrush(Colors.Black); 
pin.Content = "Example"; 
pin.Height = 40; 
pin.Width = 80; 
map1.Children.Add(pin);   //  一定要记得添加到map1这个控件中哦~ 

对于多边线,我们用到的是Polyline这样一个类，多边形的绘制使用Polygon这个类，插入图片使用MapLayer类，它们的使用跟Pushpin这个类异曲同工。

以上就是一些简单的应用，那么来点实际点的。

我在开发过程中需要使用Map控件实现动态定位，找到自己的所在位置以及某个会议要举行的位置，并在切换过程中在地图中标注出相应的位置，并支持WP7.1的多点触控进行Zoomin和Zoomout。

这需要写一个page，我把它叫做MapPage，然后它的入口接收在页面Navigate时候传过来的三个值，一个是会议举行地点的经度，一个是纬度，还有一个是label，显示在标注上的文字。下面给出源代码仅供参考。

创建一个MapPage，xaml文件如下：

<phone:PhoneApplicationPage x:Class="Client.MapPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"    
    xmlns:System="clr-namespace:System;assembly=mscorlib"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource MyPhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="728"
    shell:SystemTray.IsVisible="False"
    xmlns:my="clr-namespace:Microsoft.Phone.Controls.Maps;assembly=Microsoft.Phone.Controls.Maps"
    >

    <Canvas x:Name="LayoutRoot">

        <!-- Map View -->
        <Border x:Name="Mapw"
                Height="768" Width="480">
            <my:Map Name="Map" 
                    CredentialsProvider="{Binding CredentialsProvider}"
                    CopyrightVisibility="Collapsed"
                    LogoVisibility="Collapsed"
                    ZoomLevel="{Binding Zoom, Mode=TwoWay}"
                    Center="{Binding Center, Mode=TwoWay}"
                    >
                <my:Map.Mode>
                    <my:RoadMode />
                </my:Map.Mode>

                <my:MapItemsControl x:Name="mapControl"/>
            </my:Map>

            <!-- TODO : Add map control -->

        </Border>

    </Canvas>

    <phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="False">
            <shell:ApplicationBarIconButton IconUri="/Images/appbar.location.rest.png" Text="current" Click="CurrentLocation_Click"/>
            <shell:ApplicationBarIconButton IconUri="/Images/appbar.next.rest.png" Text="venue" Click="VenueLocation_Click"/>
        </shell:ApplicationBar>
    </phone:PhoneApplicationPage.ApplicationBar>


</phone:PhoneApplicationPage>

 

在MapPage.cs文件里完成相应的处理：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Controls.Maps;
using System.Device.Location;
using System.ComponentModel;
using Microsoft.Phone.Controls.Maps.Core;

namespace Client
{
    public partial class MapPage : PhoneApplicationPage, INotifyPropertyChanged
    {
        public MapPage()
        {
            this.Loaded += new RoutedEventHandler(MapPage_Loaded);
            InitializeComponent();
            InitializeDefaults();

            DataContext = this;
        }

        private readonly CredentialsProvider credentialsProvider = new ApplicationIdCredentialsProvider(AcademicSearch.App.BingMapsId);          
        public CredentialsProvider CredentialsProvider
        {
            get { return credentialsProvider; }
        }

        private MapLayer pushpinLayer;
        private string pushpinLabel;
        private Pushpin locationMark;
        void MapPage_Loaded(object sender, RoutedEventArgs e)
        {
            NotifyPropertyChanged("Zoom");
            NotifyPropertyChanged("Center");
            pushpinLayer = new MapLayer();
            Map.Children.Add(pushpinLayer);
            pushpinLayer.AddChild(
                new Pushpin() {Content =new Border() { Child = new TextBlock() { Text = pushpinLabel },

                            Background=new SolidColorBrush(Colors.Black)}},
                Center);
                locationMark = new Pushpin() { Content = new Border() { Child = new TextBlock() { Text = "You Are Here!" }, 

                            Background = new SolidColorBrush(Colors.Black) } };
            pushpinLayer.AddChild(locationMark, new GeoCoordinate(0, 0));
        }

        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);
            string longitudeStr;
            string latitudeStr;
            if (NavigationContext.QueryString.TryGetValue("longitude", out longitudeStr) && NavigationContext.QueryString.TryGetValue("latitude", out latitudeStr))
            {
                double latitude; 
                double longitude;
                if (Double.TryParse(latitudeStr, out latitude) && Double.TryParse(longitudeStr, out longitude))
                {
                    Center = new GeoCoordinate(latitude, longitude);
                    Venue = new GeoCoordinate(latitude, longitude);
                    Zoom = DefaultZoomLevel;
                }
                string label;
                if (NavigationContext.QueryString.TryGetValue("label", out label))
                {
                    pushpinLabel = label;
                }
                else
                {
                    pushpinLabel = "";
                }
            }
        }

        public void AddPushpin(GeoCoordinate location)
        {
            Pushpin pushpin = new Pushpin();
            pushpin.Content = "Test";
            pushpinLayer.AddChild(pushpin, location);
        }

        ///<summary>
        /// Gets or sets the map zoom level.
        ///</summary>
        private const double DefaultZoomLevel = 17.0;
        private const double MaxZoomLevel = 21.0;
        private const double MinZoomLevel = 1.0;

        private double _zoom = DefaultZoomLevel;
        public double Zoom
        {
            get { return _zoom; }
            set
            {
                var coercedZoom = Math.Max(MinZoomLevel, Math.Min(MaxZoomLevel, value));
                if (_zoom != coercedZoom)
                {
                    _zoom = value;
                    NotifyPropertyChanged("Zoom");
                }
            }
        }

        private GeoCoordinateWatcher loc = null;

        private void CurrentLocation_Click(object sender, EventArgs e)
        {
            //Zoom += 1;
            if (loc == null)
            {
                loc = new GeoCoordinateWatcher(GeoPositionAccuracy.Default);
                loc.StatusChanged += loc_StatusChanged;
            }
            if (loc.Status == GeoPositionStatus.Disabled)
            {
                loc.StatusChanged -= loc_StatusChanged;
                MessageBox.Show("Location services must be enabled on your phone.");
                return;
            }
            loc.Start();
        }

        void loc_StatusChanged(object sender, GeoPositionStatusChangedEventArgs e)
        {

            if (e.Status == GeoPositionStatus.Ready)
            {
                locationMark.Location = loc.Position.Location;
                Map.SetView(loc.Position.Location, 17.0);
                loc.Stop();
            }
        }

        private void VenueLocation_Click(object sender, EventArgs e)
        {
            Map.SetView(Venue, 17.0);
        }

        private GeoCoordinate _center;
        public GeoCoordinate Center
        {
            get { return _center; }
            set
            {
                if (_center != value)
                {
                    _center = value;
                    NotifyPropertyChanged("Center");
                }
            }
        }

        private GeoCoordinate Venue;

        public event PropertyChangedEventHandler PropertyChanged;
        private void NotifyPropertyChanged(String propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (null != handler)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        public bool HasDirections
        {
            get
            {
                // TODO : Return true only if has directions.

                return true;
            }
        }


        #region Tasks

        private void InitializeDefaults()
        {
            // TODO : Initialize default properties.
        }

        private void ChangeMapMode()
        {
            // TODO : Change map view mode.
        }

        private void IncreaseZoomLevel()
        {
            // TODO : Increases zoom level.
        }

        private void DecreaseZoomLevel()
        {
            // TODO : Decreases zoom level.
        }

        private void CenterLocation()
        {
            // TODO : Center current location.
        }

        private void CenterPushpinsPopup(Point touchPoint)
        {
            // TODO : Center pushpins popup to the touch point.
        }

        private void CreateNewPushpin(object selectedItem, Point point)
        {
            // TODO : Create a new pushpin.
        }

        private void CalculateRoute()
        {
            // TODO : Calculate a route.
        }        

        #endregion

    }
}

 

 

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