- (id) initWithFrame:(CGRect) frame{ self = [super initWithFrame:frame]; if (self) { mapView = [[MKMapView alloc] initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height)]; mapView.showsUserLocation = YES; [mapView setDelegate:self]; [self addSubview:mapView]; routeView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, mapView.frame.size.width, mapView.frame.size.height)]; routeView.userInteractionEnabled = NO; [mapView addSubview:routeView]; self.lineColor = [UIColor redColor]; } return self;}//显示两点之间的线路-(void) showRouteFrom: (Place*) f to:(Place*) t { if(routes) { [mapView removeAnnotations:[mapView annotations]]; [routes release]; } PlaceMark* from = [[[PlaceMark alloc] initWithPlace:f] autorelease]; PlaceMark* to = [[[PlaceMark alloc] initWithPlace:t] autorelease]; [mapView addAnnotation:from]; [mapView addAnnotation:to]; //计算出两点之间的线路所包含的点的数组 routes = [[self calculateRoutesFrom:from.coordinate to:to.coordinate] retain]; //根据数组画线 [self updateRouteView]; //根据线路确定呈现范围 [self centerMap];}-(NSArray*) calculateRoutesFrom:(CLLocationCoordinate2D) f to: (CLLocationCoordinate2D) t { NSString* saddr = [NSString stringWithFormat:@"%f,%f", f.latitude, f.longitude]; NSString* daddr = [NSString stringWithFormat:@"%f,%f", t.latitude, t.longitude]; NSString* apiUrlStr = [NSString stringWithFormat:@"http://maps.google.com/maps?output=dragdir&saddr=%@&daddr=%@", saddr, daddr]; NSURL* apiUrl = [NSURL URLWithString:apiUrlStr]; NSLog(@"\n api url: %@", apiUrl); NSString *apiResponse = [NSString stringWithContentsOfURL:apiUrl encoding:NSASCIIStringEncoding error:nil]; NSString* encodedPoints = [apiResponse stringByMatching:@"points:\\\"([^\\\"]*)\\\"" capture:1L]; NSLog(@"\n %@",encodedPoints); return [self decodePolyLine:[encodedPoints mutableCopy]];}/* {tooltipHtml:" (23.4\x26#160;km / 25 mins)", polylines:[{id:"route0", points:"{ntrFopdfU?rv@ZrcB??UzALrE??Ot@@bG??e@\\oF?cCp@u@???gCf@yu@C??wuAEaKHkJb@eHx@eGrA_EpAyHrDyEdDcGtFyErF_J|Mgb@dt@??yfB||Cw@bB}ApEcLv`@uBnIcAdGOjBS|Gt@bhArA`yA??rBd~BAdOHxJb@rQDhLJpD|ArkB^fWrA|sAdApm@??v@na@jCpjC??m@nDXvQ??lH_@??BbA??_@V", levels:"B?BB?BB?BB???BB?BB?@???A???@?BB@???A??@?BB?????????BB?BB?BBBBBBB", numLevels:4,zoomFactor:16}]} {ntrFopdfU?rv@ZrcB??UzALrE??Ot@@bG??e@\\oF?cCp@u@???gCf@yu@C??wuAEaKHkJb@eHx@eGrA_EpAyHrDyEdDcGtFyErF_J|Mgb@dt@??yfB||Cw@bB}ApEcLv`@uBnIcAdGOjBS|Gt@bhArA`yA??rBd~BAdOHxJb@rQDhLJpD|ArkB^fWrA|sAdApm@??v@na@jCpjC??m@nDXvQ??lH_@??BbA??_@V*///解码算法（将获取的字符串转码为地图上的坐标位置，并以此构建每一个CLLocation位置对象，然后加入数组 -(NSMutableArray *)decodePolyLine: (NSMutableString *)encoded { //替换字符串中的@"\\" 为 @"\\\\" ，检索方式为逐个字符，范围是整个字符串 [encoded replaceOccurrencesOfString:@"\\\\" withString:@"\\" options:NSLiteralSearch range:NSMakeRange(0, [encoded length])]; NSInteger len = [encoded length]; NSInteger index = 0; NSMutableArray *array = [[[NSMutableArray alloc] init] autorelease]; NSInteger lat=0; NSInteger lng=0; while (index < len) { NSInteger b; NSInteger shift = 0; NSInteger result = 0; do { b = [encoded characterAtIndex:index++] - 63; result |= (b & 0x1f) << shift; shift += 5; } while (b >= 0x20); NSInteger dlat = ((result & 1) ? ~(result >> 1) : (result >> 1)); lat += dlat; shift = 0; result = 0; do { b = [encoded characterAtIndex:index++] - 63; result |= (b & 0x1f) << shift; shift += 5; } while (b >= 0x20); NSInteger dlng = ((result & 1) ? ~(result >> 1) : (result >> 1)); lng += dlng; NSNumber *latitude = [[[NSNumber alloc] initWithFloat:lat * 1e-5] autorelease]; NSNumber *longitude = [[[NSNumber alloc] initWithFloat:lng * 1e-5] autorelease]; printf("[%f,", [latitude doubleValue]); printf("%f]", [longitude doubleValue]); CLLocation *loc = [[[CLLocation alloc] initWithLatitude:[latitude floatValue] longitude:[longitude floatValue]] autorelease]; [array addObject:loc]; } return array;}//用routes数组的内容 确定region的呈现范围-(void) centerMap { MKCoordinateRegion region; CLLocationDegrees maxLat = -90; CLLocationDegrees maxLon = -180; CLLocationDegrees minLat = 90; CLLocationDegrees minLon = 180; for(int idx = 0; idx < routes.count; idx++) { CLLocation* currentLocation = [routes objectAtIndex:idx]; if(currentLocation.coordinate.latitude > maxLat) maxLat = currentLocation.coordinate.latitude; if(currentLocation.coordinate.latitude < minLat) minLat = currentLocation.coordinate.latitude; if(currentLocation.coordinate.longitude > maxLon) maxLon = currentLocation.coordinate.longitude; if(currentLocation.coordinate.longitude < minLon) minLon = currentLocation.coordinate.longitude; } region.center.latitude = (maxLat + minLat) / 2; region.center.longitude = (maxLon + minLon) / 2; region.span.latitudeDelta = maxLat - minLat; region.span.longitudeDelta = maxLon - minLon; [mapView setRegion:region animated:YES];}//用routes数组的内容 画线-(void) updateRouteView { CGContextRef context = CGBitmapContextCreate(nil, routeView.frame.size.width, routeView.frame.size.height, 8, 4 * routeView.frame.size.width, CGColorSpaceCreateDeviceRGB(), kCGImageAlphaPremultipliedLast); CGContextSetStrokeColorWithColor(context, lineColor.CGColor); CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0); CGContextSetLineWidth(context, 3.0); for(int i = 0; i < routes.count; i++) { CLLocation* location = [routes objectAtIndex:i]; CGPoint point = [mapView convertCoordinate:location.coordinate toPointToView:routeView]; if(i == 0) { CGContextMoveToPoint(context, point.x, routeView.frame.size.height - point.y); } else { CGContextAddLineToPoint(context, point.x, routeView.frame.size.height - point.y); } } CGContextStrokePath(context); CGImageRef image = CGBitmapContextCreateImage(context); UIImage* img = [UIImage imageWithCGImage:image]; routeView.image = img; CGContextRelease(context);}#pragma mark mapView delegate functions- (void)mapView:(MKMapView *)mapView regionWillChangeAnimated:(BOOL)animated{ routeView.hidden = YES;}- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated{ [self updateRouteView]; routeView.hidden = NO; [routeView setNeedsDisplay];}- (void)dealloc { if(routes) { [routes release]; } [mapView release]; [routeView release]; [super dealloc];}#import <Foundation/Foundation.h>@interface Place : NSObject { NSString* name; NSString* description; double latitude; double longitude;}@property (nonatomic, retain) NSString* name;@property (nonatomic, retain) NSString* description;@property (nonatomic) double latitude;@property (nonatomic) double longitude;@end#import "Place.h"@implementation Place@synthesize name;@synthesize description;@synthesize latitude;@synthesize longitude;- (void) dealloc{ [name release]; [description release]; [super dealloc];}@end#import <Foundation/Foundation.h>#import <MapKit/MapKit.h>#import "Place.h"@interface PlaceMark : NSObject <MKAnnotation> { CLLocationCoordinate2D coordinate; Place* place;}@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;@property (nonatomic, retain) Place* place;-(id) initWithPlace: (Place*) p;@end#import "PlaceMark.h"@implementation PlaceMark@synthesize coordinate;@synthesize place;-(id) initWithPlace: (Place*) p{ self = [super init]; if (self != nil) { coordinate.latitude = p.latitude; coordinate.longitude = p.longitude; self.place = p; } return self;}- (NSString *)subtitle{ return self.place.description;}- (NSString *)title{ return self.place.name;}- (void) dealloc{ [place release]; [super dealloc];}@end
