我想使用纬度和经度在mapview上绘制路线。怎么可能画画？
这是我的代码。但它不起作用。我已经在点可变阵列中添加了位置。之后调用drawRoute函数在该位置之间绘制路径。
- (void)viewDidLoad {
[super viewDidLoad];
CLLocationCoordinate2D location;
location.latitude = (double) 23.00000;
location.longitude = (double) 73.00000;
CLLocationCoordinate2D location2;
location2.latitude = (double) 73.00000;
location2.longitude = (double) 23.00000;
CLLocation *locationPoint1 = [[CLLocation alloc]initWithLatitude:location.latitude longitude:location.longitude];
CLLocation *locationPoint2 = [[CLLocation alloc]initWithLatitude:location2.latitude longitude:location2.longitude];
[self.points addObject:locationPoint1];
[self.points addObject:locationPoint2];
[self performSelector:@selector(drowRoute)];
}
-(void)drowRoute{
CGContextRef context = UIGraphicsGetCurrentContext();
// CGContextSetStrokeColorWithColor(context, [[UIColor blueColor]CGColor]);
CGContextSetLineWidth(context, 2.0);
for(int idx = 0; idx < self.points.count; idx++)
{
CLLocation* location = [self.points objectAtIndex:idx];
CGPoint point = [mapView convertCoordinate:location.coordinate toPointToView:self.view];
if(idx == 0)
{
// move to the first point
CGContextMoveToPoint(context, point.x, point.y);
}
else
{
CGContextAddLineToPoint(context, point.x, point.y);
}
}
CGContextStrokePath(context);
}
答案 0 :(得分：2)
我使用谷歌地图服务。您只需将经度和纬度作为参数传递给URL，Google地图就会照顾休息。
- (void)viewDidLoad
{
[super viewDidLoad];
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
[locationManager startUpdatingLocation];
NSString *url = [NSString stringWithFormat: @"http://maps.google.com/maps?saddr=%f,%f&daddr=%f,%f",c_lat,c_long,lat,lat];
//saddr= we pass source address long, lat.
//daddr= we pass destination address long, lat.
//--------use this if you have current long,lat and destination's address or street name etc...
NSString* url = [NSString stringWithFormat: @"http://maps.google.com/maps?saddr=%f,%f&daddr=%@",
currentLocation.latitude, currentLocation.longitude,
[address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
//------------------------------------------------------------------------------
[[UIApplication sharedApplication] openURL: [NSURL URLWithString:url]]; // this line will open Google map on Maps application on device and in Safari in Simulator.
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
curntloc = [[CLLocation alloc] initWithLatitude:newLocation.coordinate.latitude longitude:newLocation.coordinate.longitude];
NSLog(@"in func--> %f %f",curntloc.coordinate.latitude, curntloc.coordinate.longitude);
}
答案 1 :(得分：1)
以下是使用lat，long坐标在地图上绘制路线的示例源代码。
http://developer.apple.com/library/ios/#samplecode/Breadcrumb/Introduction/Intro.html
这就是我学会完成任务的方法。
此外，要绘制线条，在this post中您会找到注释类。查看帖子中的源代码，我希望能为您提供更多帮助。
通过使用我发布的第二个链接中的类，您只需提供坐标（lat，long），其余类将完成：）
答案 2 :(得分：1)
使用以下代码：
-(NSMutableArray *)decodePolyLine: (NSMutableString *)encoded {
[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];
CLLocation *loc = [[[CLLocation alloc] initWithLatitude:[latitude floatValue] longitude:[longitude floatValue]] autorelease];
[array addObject:loc];
}
return array;
}
-(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];
NSString *apiResponse = [NSString stringWithContentsOfURL:apiUrl];
NSString* encodedPoints = [apiResponse stringByMatching:@"points:\\\"([^\\\"]*)\\\"" capture:1L];
return [self decodePolyLine:[encodedPoints mutableCopy]];
}
-(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];
}
-(void) calculate_distance{
float target = [location1 distanceFromLocation:location2]/1000;
text2=[NSString stringWithFormat:@"%fkm",target];
routes = [[self calculateRoutesFrom:location1.coordinate to:location2.coordinate] retain];
if([routes count]!=0){
[self updateRouteView];
[self centerMap];
UIAlertView* alert1=[[UIAlertView alloc]initWithTitle:@"MESSAGE" message:text2 delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert1 show];
[alert1 release];
}
else{
UIAlertView* alert=[[UIAlertView alloc]initWithTitle:@"MESSAGE" message:@"We could not draw direction between your desired locations" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release];
}
location1=0;
location2=0;
}
-(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);
}
答案 3 :(得分：0)
我使用下面给出的代码在两个位置之间绘制路线：
GitHub