我用什么坐标手动绘制一个MKMapView的自定义path？

有CLLocation2D点， MKMapPoints ， MKCoordinates和convertCoordinate:toPointInView:它们都以一种或另一种forms给你点。 我正在绘制一个自定义路线：

 - (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScale inContext:(CGContextRef)context { 

什么是正确的使用绘图点？

Answer 1

  routeView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, mapView.frame.size.width, mapView.frame.size.height)]; routeView.userInteractionEnabled = NO; [mapView addSubview:routeView]; 

和

 -(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, 4.0); for(int i = 0; i < self.routes.count; i++) { CLLocation* location = [self.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); 

}

Answer 2

你可以使用谷歌API喜欢 –

在.h中定义合适的variables

 NSArray *arrRoutePoints; MKPolygon *objpolygon; MKPolyline *objpolyline; 

调用函数就像你想要的地方 –

 self.arrRoutePoints=[self getRoutePointFrom:newSource to:newDestination]; [self drawRoute]; 

function代码：

  - (NSArray*)getRoutePointFrom:(MKPointAnnotation *)origin to:(MKPointAnnotation *)destination { NSString *saddress=[NSString stringWithFormat:@"%f,%f",origin.coordinate.latitude,origin.coordinate.longitude]; NSString *daddress=[NSString stringWithFormat:@"%f,%f",destination.coordinate.latitude,destination.coordinate.longitude]; NSString *apiUrlString=[NSString stringWithFormat:@"http://maps.google.com/maps?output=dragdir&saddr=%@&daddr=%@", saddress, daddress]; NSURL *apiUrl=[NSURL URLWithString:apiUrlString]; NSError *error; NSString *apiResponse=[NSString stringWithContentsOfURL:apiUrl encoding:NSUTF8StringEncoding error:&error]; NSRange range; range=[apiResponse rangeOfString:@"points:\\\"([^\\\"]*)\\\"" options:NSRegularExpressionSearch]; NSString *encodedPoint=[apiResponse substringWithRange:range]; NSLog(@"Encode lentgh %d",[encodedPoint length]); encodedPoint=[encodedPoint stringByReplacingOccurrencesOfString:@"points:\"" withString:@""]; encodedPoint=[encodedPoint stringByReplacingOccurrencesOfString:@"\"" withString:@""]; return [self decodePolyLine:[encodedPoint mutableCopy]]; } - (NSMutableArray *)decodePolyLine:(NSMutableString *)encodedString { [encodedString replaceOccurrencesOfString:@"\\\\" withString:@"\\" options:NSLiteralSearch range:NSMakeRange(0, [encodedString length])]; NSInteger len = [encodedString length]; NSInteger index = 0; NSMutableArray *array = [[NSMutableArray alloc] init]; NSInteger lat=0; NSInteger lng=0; while (index < len) { NSInteger b; NSInteger shift = 0; NSInteger result = 0; do { b = [encodedString 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 { if(index<len) { b = [encodedString characterAtIndex:index++] - 63; result |= (b & 0x1f) << shift; shift += 5; } else { break; } } while (b >= 0x20); NSInteger dlng = ((result & 1) ? ~(result >> 1) : (result >> 1)); lng += dlng; NSNumber *latitude = [[NSNumber alloc] initWithFloat:lat * 1e-5]; NSNumber *longitude = [[NSNumber alloc] initWithFloat:lng * 1e-5]; printf("\n[%f,", [latitude doubleValue]); printf("%f]", [longitude doubleValue]); CLLocation *loc = [[CLLocation alloc] initWithLatitude:[latitude floatValue] longitude:[longitude floatValue]]; [array addObject:loc]; } return array; } - (void)drawRoute { int numPoints=[arrRoutePoints count]; if(numPoints >1) { CLLocationCoordinate2D *coord=malloc(numPoints *sizeof(CLLocationCoordinate2D)); for(int i=0;i<numPoints;i++) { CLLocation *current=[arrRoutePoints objectAtIndex:i]; NSLog(@"%@",[arrRoutePoints objectAtIndex:i]); NSLog(@"Current \n[%g",current.coordinate.latitude); NSLog(@"%g]",current.coordinate.longitude); coord[i]=current.coordinate; NSLog(@"\n[%g",coord[i].latitude); NSLog(@"%g]",coord[i].longitude); } self.objpolyline=[MKPolyline polylineWithCoordinates:coord count:numPoints]; free(coord); [mapView addOverlay:objpolyline]; [mapView setNeedsDisplay]; } }