我正在开发一款iOS应用，该应用使用Google Directions API在Google Maps SDK提供的地图上绘制路线。它适用于小距离，但是当我非常接近地缩放地图相机时，我看到路线折线经常走出街道。当距离较长时，这是一场真正的灾难，如果我放大，它就不会跟随街道曲线。我从Directions API获得的概览 - 折线得到了点，但似乎折线不是那么多边形我想要。在Android上它完美无缺。难道Google会向iOS发送与Android不同的指示吗？你们有些人和我有同样的问题吗？
修改
-(int) requestDirecionsAndshowOnMap:(GMSMapView *)aMapView{
NSArray* mode=[[NSArray alloc]initWithObjects:@"transit",@"bicycling",@"walking",@"driving", nil];
NSString *depart=[[NSString alloc] initWithFormat:@""];
NSString *origin=[[NSString alloc] initWithFormat:@""];
NSString *destination=[[NSString alloc] initWithFormat:@""];
if (self.setLanguage)
self.setLanguage=[NSString stringWithFormat:@"language=%@",self.setLanguage];
else self.setLanguage=@"language=en";
if (searchModeOption==0) {
if (self.departDate==nil) {
self.departDate=[NSDate date];
}
depart=[NSString stringWithFormat:@"&departure_time=%i",(int)[self.departDate timeIntervalSince1970]];
}
if (self.origin) {
origin=[NSString stringWithFormat:@"origin=%@",self.origin];
}else if (self.originCoordinate.latitude && self.originCoordinate.longitude){
origin=[NSString stringWithFormat:@"origin=%f,%f",self.originCoordinate.latitude,self.originCoordinate.longitude];
}else{
NSLog(@"No origin setted");
return -1;
}
if (self.destination) {
destination=[NSString stringWithFormat:@"destination=%@",self.destination];
}else if (self.destinationCoordinate.latitude && self.destinationCoordinate.longitude){
destination=[NSString stringWithFormat:@"destination=%f,%f",self.destinationCoordinate.latitude,self.destinationCoordinate.longitude];
}else{
NSLog(@"No destination setted");
return -1;
}
NSString* URLforRequest=[[NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/directions/json?%@&%@&sensor=false&%@&alternative=false&mode=%@%@",origin,destination,self.setLanguage,[mode objectAtIndex:searchModeOption],depart] stringByAddingPercentEscapesUsingEncoding: NSASCIIStringEncoding];
// NSLog(@"%@",URLforRequest);
NSURLRequest *requests = [NSURLRequest requestWithURL:[NSURL URLWithString:URLforRequest]];
[NSURLConnection sendAsynchronousRequest:requests queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error){
if (error==nil && data) {
// NSLog(@"%@",[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);
directions = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&error];
if (error) {
NSLog(@"%@",error);
}
NSString* status=[directions objectForKey:@"status"];
NSLog(@"Status: %@", status);
if ([status isEqualToString:@"OK"]) {
[self decodeResult];
if (aMapView)
[self showOnMap:aMapView];
}
}else NSLog(@"%@",error);
[[NSNotificationCenter defaultCenter] postNotificationName:@"Request Done" object:nil];
}];
return 0;
}
-(void) decodeResult{
self.destination=[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"end_address"];
self.distance=[[[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"distance"] objectForKey:@"text"] doubleValue];
self.duration=[[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"duration"] objectForKey:@"text"];
//Get Array of Instructions
self.instrunctions=[[NSMutableArray alloc] init];
for (int n=0; n<[[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"]count]; n++) {
[self.instrunctions addObject:[[[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"] objectAtIndex:n] objectForKey:@"html_instructions"]];
}
//Get Overview Polyline
NSString *polystring=[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"overview_polyline"] objectForKey:@"points"];
NSMutableArray* decodedpolystring=[self decodePolyLine:polystring];
int numberOfCC=[decodedpolystring count];
GMSMutablePath *path = [GMSMutablePath path];
for (int index = 0; index < numberOfCC; index++) {
CLLocation *location = [decodedpolystring objectAtIndex:index];
CLLocationCoordinate2D coordinate = location.coordinate;
[path addLatitude:coordinate.latitude longitude:coordinate.longitude];
}
self.overviewPolilyne= [GMSPolyline polylineWithPath:path];
//Get Coordinates of origin and destination to be displayed on a map
float lat=[[[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"]objectAtIndex:0] objectForKey:@"end_location"] objectForKey:@"lat"] floatValue];
float lng=[[[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"]objectAtIndex:0] objectForKey:@"end_location"] objectForKey:@"lng"] floatValue];
CLLocationCoordinate2D tmp;
tmp.latitude=lat;
tmp.longitude=lng;
self.destinationCoordinate=tmp;
lat=[[[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"]objectAtIndex:0] objectForKey:@"start_location"] objectForKey:@"lat"] floatValue];
lng=[[[[[[[directions objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"]objectAtIndex:0] objectForKey:@"start_location"] objectForKey:@"lng"] floatValue];
tmp.latitude=lat;
tmp.longitude=lng;
self.originCoordinate=tmp;
}
-(NSMutableArray *)decodePolyLine:(NSString *)encodedStr {
NSMutableString *encoded = [[NSMutableString alloc] initWithCapacity:[encodedStr length]];
[encoded appendString:encodedStr];
[encoded replaceOccurrencesOfString:@"\\\\" withString:@"\\"
options:NSLiteralSearch
range:NSMakeRange(0, [encoded length])];
NSInteger len = [encoded 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 = [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];
NSNumber *longitude = [[NSNumber alloc] initWithFloat:lng * 1e-5];
CLLocation *location = [[CLLocation alloc] initWithLatitude:[latitude floatValue] longitude:[longitude floatValue]];
[array addObject:location];
}
return array;
}
-(void)showOnMap:(GMSMapView *)aMapView{
GMSPolyline *polyline =self.overviewPolilyne;
polyline.strokeColor = [UIColor blueColor];
polyline.strokeWidth = 2.f;
//polyline.geodesic = YES;
polyline.map = aMapView; }
更新 我必须处理每一步的折线，而不仅仅是概览折线。现在它完美无缺。
这是我现在使用的代码：
// Get polyline
GMSMutablePath *path = [GMSMutablePath path];
NSMutableArray *polyLinesArray = [[NSMutableArray alloc] init];
int zero=0;
NSArray *steps = [[[[[directions objectForKey:@"routes"] objectAtIndex:zero] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"];
for (int i=0; i<[[[[[[directions objectForKey:@"routes"] objectAtIndex:zero] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"]count]; i++) {
NSString* encodedPoints =[[[steps objectAtIndex:i]objectForKey:@"polyline"]valueForKey:@"points"];
polyLinesArray = [self decodePolyLine:encodedPoints];
NSUInteger numberOfCC=[polyLinesArray count];
for (NSUInteger index = 0; index < numberOfCC; index++) {
CLLocation *location = [polyLinesArray objectAtIndex:index];
CLLocationCoordinate2D coordinate = location.coordinate;
[path addLatitude:coordinate.latitude longitude:coordinate.longitude];
if (index==0) {
[self.coordinates addObject:location];
}
}
}
self.overviewPolilyne = [GMSPolyline polylineWithPath:path];
我之前基本上做过的是，我只使用routes中收到的信息，而如果您查看从Google Directions API收到的JSON文件，您会看到您在<legs>和<steps>中收到了更多信息。这是我们生成正确结果和正确折线所需的信息。
祝好运！ ：）