使用Google地图SDK在地图上绘制错误多段线

使用Google地图SDK在地图上绘制错误多段线

本文介绍了使用Google地图SDK在地图上绘制错误多段线的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我正在尝试使用Google地图SDK在我的地图上绘制路线。
是我调用的URL,我解析了对坐标数组的JSON响应:

  id jsonResponse = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil]; 

int points_count = 0;
points_count = [[[[[[[jsonResponse objectForKey:@routes] objectAtIndex:0] objectForKey:@legs] objectAtIndex:0] objectForKey:@steps] count];

NSArray * steps = nil;
if(points_count&& [[[[jsonResponse objectForKey:@routes] objectAtIndex:0] objectForKey:@legs] count])
{
steps = [[ [[[jsonResponse objectForKey:@routes] objectAtIndex:0] objectForKey:@legs] objectAtIndex:0] objectForKey:@steps];
}

NSMutableArray * coordinates = [[NSMutableArray alloc] initWithCapacity:points_count];
for(int i = 0; i< points_count; i ++)
{
NSDictionary * start;
NSDictionary *完成;

double st_lat = [[[[steps [objectAtIndex:i] objectForKey:@start_location] valueForKey:@lat] doubleValue];
double st_lon = [[[[steps [objectAtIndex:i] objectForKey:@start_location] valueForKey:@lng] doubleValue];

if(st_lat> 0.0f& st_lon> 0.0f)
{
start = @ {@latitude:[NSNumber numberWithDouble:st_lat], @longitude:[NSNumber numberWithDouble:st_lon]};
}

double end_lat = [[[[steps [objectAtIndex:i] objectForKey:@end_location] valueForKey:@lat] doubleValue];
double end_lon = [[[[steps [objectAtIndex:i] objectForKey:@end_location] valueForKey:@lng] doubleValue];

if(end_lat> 0.0f&& end_lon> 0.0f)
{
finish = @ {@latitude:[NSNumber numberWithDouble:end_lat], @longitude:[NSNumber numberWithDouble:end_lon]};
}

[坐标addObject:@ {@start:start,@finish:finish}];
}

比使用此方法绘制地图视图:

  GMSMutablePath * path = [GMSMutablePath path]; 
for(NSDictionary * d in directions)
{
NSDictionary * start = d [@start];
NSDictionary * finish = d [@finish];

CLLocationCoordinate2D c_start = CLLocationCoordinate2DMake([start [@latitude] doubleValue],[start [@longitude] doubleValue]);
CLLocationCoordinate2D c_finish = CLLocationCoordinate2DMake([finish [@latitude] doubleValue],[finish [@longitude] doubleValue]);

[path addCoordinate:c_start];
[path addCoordinate:c_finish];
}

GMSPolyline * line = [GMSPolyline polylineWithPath:path];
line.strokeColor = [UIColor redColor];
line.strokeWidth = 2.0f;
line.map = self.mapView;


我在这里做错了什么?

解决方案

所以问题是我用 start_location end_location 而不是 polyline - > points 。修正了我的代码:



请求URL例如: https://maps.googleapis.com/maps/api/directions/json?来源= 40.716072,-74.008836和目的地= 40.697545,-73.983892& sensor = false& waypoints = optimize:true& mode = driving

  id jsonResponse = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil]; 

int points_count = 0;
points_count = [[[[[[[jsonResponse objectForKey:@routes] objectAtIndex:0] objectForKey:@legs] objectAtIndex:0] objectForKey:@steps] count];

NSArray * steps = nil;
if(points_count&& [[[[jsonResponse objectForKey:@routes] objectAtIndex:0] objectForKey:@legs] count])
{
steps = [[ [[[jsonResponse objectForKey:@routes] objectAtIndex:0] objectForKey:@legs] objectAtIndex:0] objectForKey:@steps];
}

NSMutableArray * coordinates = [[NSMutableArray alloc] initWithCapacity:points_count];
for(int i = 0; i< points_count; i ++)
{
NSString * toDecode = [[[steps objectAtIndex:i] objectForKey:@polyline] valueForKey:@点];
NSArray * locations = [AppUtils decodePolylineWithString:toDecode];

for(int i = 0; i< locations.count; i ++)
{
if(i!= locations.count - 1){
CLLocation * start = [locations objectAtIndex:i];
CLLocation * finish = [locations objectAtIndex:i + 1];
[坐标addObject:@ {@start:start,@finish:finish}];
}
}
}

GMSMutablePath * path = [GMSMutablePath path];
for(NSDictionary * d in directions)
{
CLLocation * start = d [@start];
CLLocation * finish = d [@finish];

[path addCoordinate:start.coordinate];
[path addCoordinate:finish.coordinate];
}

GMSPolyline * line = [GMSPolyline polylineWithPath:path];
line.strokeColor = [UIColor redColor];
line.strokeWidth = 2.0f;
line.map = self.mapView;

$ b +(NSArray *)decodePolylineWithString :( NSString *)encodedString
{
NSMutableArray * coordinates = [NSMutableArray array];
const char * bytes = [encodedString UTF8String];
NSUInteger length = [encodedString lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
NSUInteger idx = 0;

NSUInteger count = length / 4;
CLLocationCoordinate2D * coords = calloc(count,sizeof(CLLocationCoordinate2D));
NSUInteger coordIdx = 0;

float latitude = 0;
float longitude = 0;
while(idx< length){
char byte = 0;
int res = 0;
char shift = 0;

do {
byte = bytes [idx ++] - 63;
res | =(byte& 0x1F)<<转移;
shift + = 5;
} while(byte> = 0x20); (res& 1)?〜(res>> 1):(res>> 1));

float deltaLat =
latitude + = deltaLat;

shift = 0;
res = 0;

do {
byte = bytes [idx ++] - 0x3F;
res | =(byte& 0x1F)<<转移;
shift + = 5;
} while(byte> = 0x20); (res& 1)?〜(res>> 1):(res>> 1));

float deltaLon =
longitude + = deltaLon;

float finalLat =纬度* 1E-5;
float finalLon = longitude * 1E-5;

CLLocationCoordinate2D coord = CLLocationCoordinate2DMake(finalLat,finalLon);
coords [coordIdx ++] = coord;
CLLocation * location = [[CLLocation alloc] initWithLatitude:finalLat longitude:finalLon];
[coordinates addObject:location];

if(coordIdx == count){
NSUInteger newCount = count + 10;
coords = realloc(coords,newCount * sizeof(CLLocationCoordinate2D));
count = newCount;
}
}

free(coords);
返回坐标;
}

我知道这有点肮脏,但这很有效,而且效果很好。

享受。

I'm trying to draw route on my map using Google Maps SDK.This is the URL that i'm calling and I parse the JSON response to array of coordinates:

    id jsonResponse = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil];

    int points_count = 0;
    points_count = [[[[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"] count];

    NSArray *steps = nil;
    if (points_count && [[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] count])
    {
        steps = [[[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"];
    }

    NSMutableArray *coordinates = [[NSMutableArray alloc] initWithCapacity:points_count];
    for (int i = 0; i < points_count; i++)
    {
        NSDictionary *start;
        NSDictionary *finish;

        double st_lat = [[[[steps objectAtIndex:i] objectForKey:@"start_location"] valueForKey:@"lat"] doubleValue];
        double st_lon = [[[[steps objectAtIndex:i] objectForKey:@"start_location"] valueForKey:@"lng"] doubleValue];

        if (st_lat > 0.0f && st_lon > 0.0f)
        {
            start = @{ @"latitude" : [NSNumber numberWithDouble:st_lat], @"longitude" : [NSNumber numberWithDouble:st_lon] };
        }

        double end_lat = [[[[steps objectAtIndex:i] objectForKey:@"end_location"] valueForKey:@"lat"] doubleValue];
        double end_lon = [[[[steps objectAtIndex:i] objectForKey:@"end_location"] valueForKey:@"lng"] doubleValue];

        if (end_lat > 0.0f && end_lon > 0.0f)
        {
            finish = @{ @"latitude" : [NSNumber numberWithDouble:end_lat], @"longitude" : [NSNumber numberWithDouble:end_lon] };
        }

        [coordinates addObject:@{ @"start" : start, @"finish" : finish }];
    }

And than drawing on the map view with this method:

GMSMutablePath *path = [GMSMutablePath path];
for (NSDictionary *d in directions)
{
    NSDictionary *start = d[@"start"];
    NSDictionary *finish = d[@"finish"];

    CLLocationCoordinate2D c_start = CLLocationCoordinate2DMake([start[@"latitude"] doubleValue], [start[@"longitude"] doubleValue]);
    CLLocationCoordinate2D c_finish = CLLocationCoordinate2DMake([finish[@"latitude"] doubleValue], [finish[@"longitude"] doubleValue]);

    [path addCoordinate:c_start];
    [path addCoordinate:c_finish];
}

GMSPolyline *line = [GMSPolyline polylineWithPath:path];
line.strokeColor = [UIColor redColor];
line.strokeWidth = 2.0f;
line.map = self.mapView;

Why it is drawing like that and not going into the street it self?

What am I doing wrong here?

解决方案

So the problem was that I used the start_location and end_location instead of the polyline -> points. Fixed my code into this:

Request URL for example: https://maps.googleapis.com/maps/api/directions/json?origin=40.716072,-74.008836&destination=40.697545,-73.983892&sensor=false&waypoints=optimize:true&mode=driving

id jsonResponse = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil];

int points_count = 0;
points_count = [[[[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"] count];

NSArray *steps = nil;
if (points_count && [[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] count])
{
    steps = [[[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"];
}

NSMutableArray *coordinates = [[NSMutableArray alloc] initWithCapacity:points_count];
for (int i = 0; i < points_count; i++)
{
    NSString *toDecode = [[[steps objectAtIndex:i] objectForKey:@"polyline"] valueForKey:@"points"];
    NSArray *locations = [AppUtils decodePolylineWithString:toDecode];

    for (int i = 0 ; i < locations.count ; i++)
    {
        if (i != locations.count - 1) {
            CLLocation *start = [locations objectAtIndex:i];
            CLLocation *finish = [locations objectAtIndex:i + 1];
            [coordinates addObject:@{ @"start" : start, @"finish" : finish }];
        }
    }
}

GMSMutablePath *path = [GMSMutablePath path];
for (NSDictionary *d in directions)
{
    CLLocation *start = d[@"start"];
    CLLocation *finish = d[@"finish"];

    [path addCoordinate:start.coordinate];
    [path addCoordinate:finish.coordinate];
}

GMSPolyline *line = [GMSPolyline polylineWithPath:path];
line.strokeColor = [UIColor redColor];
line.strokeWidth = 2.0f;
line.map = self.mapView;


+ (NSArray*)decodePolylineWithString:(NSString *)encodedString
{
    NSMutableArray *coordinates = [NSMutableArray array];
    const char *bytes = [encodedString UTF8String];
    NSUInteger length = [encodedString lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
    NSUInteger idx = 0;

    NSUInteger count = length / 4;
    CLLocationCoordinate2D *coords = calloc(count, sizeof(CLLocationCoordinate2D));
    NSUInteger coordIdx = 0;

    float latitude = 0;
    float longitude = 0;
    while (idx < length) {
       char byte = 0;
        int res = 0;
        char shift = 0;

        do {
            byte = bytes[idx++] - 63;
            res |= (byte & 0x1F) << shift;
            shift += 5;
        } while (byte >= 0x20);

        float deltaLat = ((res & 1) ? ~(res >> 1) : (res >> 1));
        latitude += deltaLat;

        shift = 0;
        res = 0;

        do {
            byte = bytes[idx++] - 0x3F;
            res |= (byte & 0x1F) << shift;
            shift += 5;
        } while (byte >= 0x20);

        float deltaLon = ((res & 1) ? ~(res >> 1) : (res >> 1));
        longitude += deltaLon;

        float finalLat = latitude * 1E-5;
        float finalLon = longitude * 1E-5;

        CLLocationCoordinate2D coord = CLLocationCoordinate2DMake(finalLat, finalLon);
        coords[coordIdx++] = coord;
        CLLocation *location = [[CLLocation alloc] initWithLatitude:finalLat longitude:finalLon];
        [coordinates addObject:location];

        if (coordIdx == count) {
            NSUInteger newCount = count + 10;
            coords = realloc(coords, newCount * sizeof(CLLocationCoordinate2D));
            count = newCount;
        }
    }

    free(coords);
    return coordinates;
}

I know it's a little bit dirty, but that's work and it works great.

Enjoy.

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08-31 04:14