如何从当前位置到目的地位置绘制路线图。 我想从我当前的位置（即设备GPS位置）在mapview上绘制路线图。到目的地{d}
using System;
using System.Drawing;
using MonoTouch.CoreLocation;
using MonoTouch.MapKit;
using MonoTouch.UIKit;
using MonoTouch.Foundation;
using System.Security.Cryptography.X509Certificates;
namespace IOS {
public class MapViewController : UIViewController {
MKMapView mapView;
UIView customHeader;
UIButton btn_Back;
UISegmentedControl mapTypes;
public float destinationLatitude = 0.0f, destinationLongitude = 0.0f;
public string storeName = "N.A.";
public string storeLocation = "N.A.";
public MapViewController (){
mapView = new MKMapView ();
mapView.AutoresizingMask = UIViewAutoresizing.FlexibleDimensions;
mapView.Frame = new RectangleF (0, 60, View.Frame.Size.Width, View.Frame.Size.Height);
int typesWidth=260, typesHeight=30, distanceFromBottom=60;
mapTypes = new UISegmentedControl(new RectangleF((View.Bounds.Width-typesWidth)/2, View.Bounds.Height-distanceFromBottom, typesWidth, typesHeight));
mapTypes.InsertSegment("Road", 0, false);
mapTypes.InsertSegment("Satellite", 1, false);
mapTypes.InsertSegment("Hybrid", 2, false);
mapTypes.InsertSegment ("Direction",3,false);
mapTypes.SelectedSegment = 0; // Road is the default
mapTypes.AutoresizingMask = UIViewAutoresizing.FlexibleTopMargin;
mapTypes.ValueChanged += (s, e) => {
switch(mapTypes.SelectedSegment) {
case 0:
mapView.MapType = MKMapType.Standard;
break;
case 1:
mapView.MapType = MKMapType.Satellite;
break;
case 2:
mapView.MapType = MKMapType.Hybrid;
break;
case 3:
Console.WriteLine ("drawing route");
break;
}
};
View.AddSubview(mapView);
View.AddSubview (mapTypes);
}
public override void ViewDidLoad (){
base.ViewDidLoad ();
Title = "Store Location";
}
public override void ViewWillAppear (bool animated){
base.ViewWillAppear (animated);
var coords = new CLLocationCoordinate2D(destinationLatitude, destinationLongitude);
var span = new MKCoordinateSpan(MilesToLatitudeDegrees (2), MilesToLongitudeDegrees (2, coords.Latitude));
// set the coords and zoom on the map
mapView.Region = new MKCoordinateRegion (coords, span);
// assign the delegate, which handles annotation layout and clicking
mapView.Delegate = new MapDelegate();
// add a basic annotation
var annotation = new BasicMapAnnotation (new CLLocationCoordinate2D (destinationLatitude, destinationLongitude), "StoreName", storeLocation);
mapView.AddAnnotation (annotation);
}
/// <summary>
/// Converts miles to latitude degrees
/// </summary>
public double MilesToLatitudeDegrees(double miles){
double earthRadius = 3960.0;
double radiansToDegrees = 180.0/Math.PI;
return (miles/earthRadius) * radiansToDegrees;
}
/// <summary>
/// Converts miles to longitudinal degrees at a specified latitude
/// </summary>
public double MilesToLongitudeDegrees(double miles, double atLatitude)
{
double earthRadius = 3960.0;
double degreesToRadians = Math.PI/180.0;
double radiansToDegrees = 180.0/Math.PI;
// derive the earth's radius at that point in latitude
double radiusAtLatitude = earthRadius * Math.Cos(atLatitude * degreesToRadians);
return (miles / radiusAtLatitude) * radiansToDegrees;
}
// The map delegate is much like the table delegate.
protected class MapDelegate : MKMapViewDelegate{
protected string annotationIdentifier = "BasicAnnotation";
UIButton detailButton;
/// <summary>
/// This is very much like the GetCell method on the table delegate
/// </summary>
public override MKAnnotationView GetViewForAnnotation (MKMapView mapView, NSObject annotation)
{
// try and dequeue the annotation view
MKAnnotationView annotationView = mapView.DequeueReusableAnnotation(annotationIdentifier);
// if we couldn't dequeue one, create a new one
if (annotationView == null)
annotationView = new MKPinAnnotationView(annotation, annotationIdentifier);
else // if we did dequeue one for reuse, assign the annotation to it
annotationView.Annotation = annotation;
// configure our annotation view properties
annotationView.CanShowCallout = true;
(annotationView as MKPinAnnotationView).AnimatesDrop = true;
(annotationView as MKPinAnnotationView).PinColor = MKPinAnnotationColor.Green;
annotationView.Selected = true;
// you can add an accessory view, in this case, we'll add a button on the right, and an image on the left
detailButton = UIButton.FromType(UIButtonType.DetailDisclosure);
detailButton.TouchUpInside += (s, e) => {
Console.WriteLine ("Clicked");
new UIAlertView("Annotation Clicked", "You clicked on " +
(annotation as MKAnnotation).Coordinate.Latitude.ToString() + ", " +
(annotation as MKAnnotation).Coordinate.Longitude.ToString() , null, "OK", null).Show();
};
annotationView.RightCalloutAccessoryView = detailButton;
// annotationView.LeftCalloutAccessoryView = new UIImageView(UIImage.FromBundle("29_icon.png"));
return annotationView;
}
// as an optimization, you should override this method to add or remove annotations as the
// map zooms in or out.
public override void RegionChanged (MKMapView mapView, bool animated) {}
}
protected class BasicMapAnnotation : MKAnnotation
{
/// <summary>
/// The location of the annotation
/// </summary>
public override CLLocationCoordinate2D Coordinate { get; set; }
protected string title;
protected string subtitle;
/// <summary>
/// The title text
/// </summary>
public override string Title
{ get { return title; } }
/// <summary>
/// The subtitle text
/// </summary>
public override string Subtitle
{ get { return subtitle; } }
public BasicMapAnnotation (CLLocationCoordinate2D coordinate, string title, string subTitle)
: base()
{
this.Coordinate = coordinate;
this.title = title;
this.subtitle = subTitle;
}
}
}
}
答案 0 :(得分：1)
我正在使用this tutorial，这实际上是说它是从MKDirections对象调用CalculateDirections。作为参考，这是Davidson Blake的代码：
使用MonoTouch.MapKit; 使用MonoTouch.CoreLocation;
//in class:
private MKMapView _map;
private MKMapViewDelegate _mapDelegate;
public override void ViewDidLoad() {
base.ViewDidLoad();
//Init Map
_map = new MKMapView
{
MapType = MKMapType.Standard,
ShowsUserLocation = true,
ZoomEnabled = true,
ScrollEnabled = true
};
//Create new MapDelegate Instance
_mapDelegate = new MapDelegate();
//Add delegate to map
_map.Delegate = _mapDelegate;
View = _map;
//Create Directions
CreateRoute();
}
//in createroute
//Create Origin and Dest Place Marks and Map Items to use for directions
//Start at Xamarin SF Office
var orignPlaceMark = new MKPlacemark(new CLLocationCoordinate2D(37.797530, -122.402590), null);
var sourceItem = new MKMapItem(orignPlaceMark);
//End at Xamarin Cambridge Office
var destPlaceMark = new MKPlacemark(new CLLocationCoordinate2D(42.374172, -71.120639), null);
var destItem = new MKMapItem(destPlaceMark);
var request = new MKDirectionsRequest
{
Source = sourceItem,
Destination = destItem,
RequestsAlternateRoutes = true
};
var directions = new MKDirections(request);
directions.CalculateDirections((response, error) =>
{
if (error != null)
{
Console.WriteLine(error.LocalizedDescription);
}
else
{
//Add each Polyline from route to map as overlay
foreach (var route in response.Routes)
{
_map.AddOverlay(route.Polyline);
}
}
});
class MapDelegate : MKMapViewDelegate
{
//Override OverLayRenderer to draw Polyline from directions
public override MKOverlayRenderer OverlayRenderer(MKMapView mapView, IMKOverlay overlay)
{
if (overlay is MKPolyline)
{
var route = (MKPolyline)overlay;
var renderer = new MKPolylineRenderer(route) { StrokeColor = UIColor.Blue };
return renderer;
}
return null;
}
}
}