Ios 地图路线视图显示不正确

我实现了一个map，它工作得很好。但当我尝试放大地图时，我发现了这个问题：

这是我的密码：

-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
    MKAnnotationView* annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"LocationPin"];
    if ([annotation isEqual:self.startLocation]) {
        annotationView.image = [UIImage imageNamed:@"startPin.png"];
        return annotationView;
    } else if ([annotation isEqual:self.endLocation]){
        annotationView.image = [UIImage imageNamed:@"endPin.png"];
        return annotationView;
    }

    return nil;
}

- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id<MKOverlay>)overlay {
    @autoreleasepool {
        if ([overlay isKindOfClass:[MKPolyline class]]) {
            MKPolylineRenderer *renderer = [[MKPolylineRenderer alloc] initWithOverlay:overlay];
            [renderer setStrokeColor:kColor_Magenta];
            [renderer setLineWidth:4.0];
            return renderer;
        }
        return nil;
    }

}

-（MKAnnotationView*）地图视图：（MKMapView*）地图视图注释：（id）注释
{
MKAnnotationView*annotationView=[[MKAnnotationView alloc]initWithAnnotation:annotation重用标识符：@“LocationPin”]；
if（[annotation isEqual:self.startLocation]）{
annotationView.image=[UIImage ImageName:@“startPin.png”]；
返回注释视图；
}else if（[annotation isEqual:self.endLocation]）{
annotationView.image=[UIImage ImageName:@“endPin.png”]；
返回注释视图；
}
返回零；
}
-（MKOverlayRenderer*）地图视图：（MKMapView*）地图视图渲染器ForOverlay:（id）overlay{
@自动释放池{
if（[overlay iskindof类：[MKPolyline类]]）{
MKPolylineRenderer*渲染器=[[MKPolylineRenderer alloc]initWithOverlay:overlay]；
[颜色：kColor_洋红]；
[渲染器设置线宽：4.0]；
返回渲染器；
}
返回零；
}
}

这可能与缩放时重新绘制多段线有关。检查这个答案

-（void）LoadMapRoute:（NSString*）源地址和目标地址：（NSString*）目标地址
{
NSString*strUrl；
strUrl=[NSString stringWithFormat:@”http://maps.googleapis.com/maps/api/directions/json?origin=%@&目的地=%@&传感器=true“，源地址，目的地地址]；
NSLog（@“strUrl===%@），strUrl）；
strUrl=[strUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]；
NSData*data=[NSData data WITHCONTENTSOFURL:[NSURL URLWithString:strUrl]]；
n错误*错误；
如果（数据）{
NSDictionary*json=[NSJSONSerialization
JSONObjectWithData:data//1
选项：针织品
错误：&错误]；
NSArray*arrRouts=[json objectForKey:@“routes”]；
if（[arrRouts iskindof类：[NSArray类]]&&arrRouts.count==0）{
[自我展示提醒：@“未找到方向”]；
返回；
}
NSArray*arrDistance=[[json valueForKeyPath:@“routes.legs.steps.distance.text”]objectAtIndex:0]objectAtIndex:0]；
NSString*totalDuration=[[json valueForKeyPath:@“routes.legs.duration.text”]objectAtIndex:0]objectAtIndex:0]；
NSString*totalDistance=[[json valueForKeyPath:@“routes.legs.distance.text”]objectAtIndex:0]objectAtIndex:0]；
NSArray*arrDescription=[[json valueForKeyPath:@“routes.legs.steps.html_指令”]objectAtIndex:0]objectAtIndex:0]；
dictRouteInfo=[NSDictionary Dictionary Dictionary WithObjectsSandKey:totalDistance、@“totalDistance”、totalDuration、@“totalDuration”、arrDistance、@“distance”、arrDescription、@“description”、nil]；
[self.btnDirection setEnabled:否]；
如果（dictRouteInfo）{
[self.btnDirection setEnabled:是]；
}
NSArray*arrpolyline=[[[json valueForKeyPath:@“routes.legs.steps.polyline.points”]objectAtIndex:0]objectAtIndex:0]；//2
double srcLat=[[[json valueForKeyPath:@“routes.legs.start_location.lat”]objectAtIndex:0]objectAtIndex:0]doubleValue]；
double srcLong=[[[json valueForKeyPath:@“routes.legs.start_location.lng”]objectAtIndex:0]objectAtIndex:0]doubleValue]；
double destrat=[[[json valueForKeyPath:@“routes.legs.end_location.lat”]objectAtIndex:0]objectAtIndex:0]doubleValue]；
double destLong=[[[json valueForKeyPath:@“routes.legs.end_location.lng”]objectAtIndex:0]objectAtIndex:0]doubleValue]；
CLLocationCoordinate2D sourceCordinate=CLLocationCoordinate2DMake（srcLat，srcLong）；
CLLocationCoordinate2D destCordinate=CLLocationCoordinate2DMake（destLat，destLong）；
[self-AddAnnotationsCandDestination:sourceCordinate:destCordinate and-Address:SourceAddress and DestinationAddress:DestinationAdds]；
//NSArray*步骤=[[aary objectAtIndex:0]valueForKey:@“步骤”]；
//将管路更换为此可能会起作用
NSMutableArray*polyLinesArray=[[NSMutableArray alloc]initWithCapacity:0]；
对于（int i=0；i<[多段线计数]；i++）
{
NSString*encodedPoints=[arrpolyline objectAtIndex:i]；
MKPolyline*route=[带encodedString的自多段线：encodedPoints]；
[多段线阵列添加对象：路由]；
}
[self.mapShow addOverlays:polyLinesArray]；
self.mapShow.delegate=self；
[self zoomtofitmanotations:self.mapShow]；
}否则{
[self.btnDirection setEnabled:否]；
[自我展示提醒：@“未找到方向”]；
}
}
#杂注标记-在源和目标上添加注释
-（void）addAnnotationSrcAndDestination:（CLLocationCoordinate2D）srcCord:（CLLocationCoordinate2D）destCord和adds:（NSString*）源地址和目的地址：（NSString*）目的地址adds
{
MKPointAnnotation*sourceAnnotation=[[MKPointAnnotation alloc]init]；
MKPointAnnotation*destAnnotation=[[MKPointAnnotation alloc]init]；
sourceAnnotation.coordinate=srcCord；
destAnnotation.coordinate=destCord；
sourceAnnotation.title=源地址；
destAnnotation.title=DestinationAdds；
[self.mapShow addAnnotation:sourceAnnotation]；
[self.mapShow addAnnotation:destAnnotation]；
}
#pragma标记-解码地图多段线
-（MKPolyline*）带encodedString的polyline:（NSString*）encodedString{
常量字符*字节=[encodedString UTF8String]；
NSUTInteger长度=[encodedString LengthofBytes使用编码：NSUTF8StringEncoding]；
整数idx=0；
NSU整数计数=长度/4；
CLLocationCoordinate2D*coords=calloc（count，sizeof（CLLocationCoordinate2D））；
NSU整数坐标=0；
浮动纬度=0；
浮动经度=0；
while（idx>1）：（res>>1））；
纬度+=三角洲；
移位=0；
res=0；
做{
字节=字节[idx++]-0x3F；
res |=（字节&0x1F）=0x20）；
浮点数=（（res&1）～（res>>1）：（res>>1））；
朗
-(void)LoadMapRoute:(NSString*)SourceAddress andDestinationAddress:(NSString*)DestinationAdds
{
NSString *strUrl;
strUrl= [NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/directions/json?origin=%@&destination=%@&sensor=true",SourceAddress,DestinationAdds];
NSLog(@"strUrl=====%@",strUrl);
strUrl=[strUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSData *data =[NSData dataWithContentsOfURL:[NSURL URLWithString:strUrl]];
NSError* error;
if (data) {
    NSDictionary* json = [NSJSONSerialization
                          JSONObjectWithData:data //1
                          options:kNilOptions
                          error:&error];
    NSArray *arrRouts=[json objectForKey:@"routes"];
    if ([arrRouts isKindOfClass:[NSArray class]]&&arrRouts.count==0) {
        [self ShowAlert:@"didn't find direction"];
        return;
    }
    NSArray *arrDistance =[[[json valueForKeyPath:@"routes.legs.steps.distance.text"] objectAtIndex:0]objectAtIndex:0];
    NSString *totalDuration = [[[json valueForKeyPath:@"routes.legs.duration.text"] objectAtIndex:0]objectAtIndex:0];
    NSString *totalDistance = [[[json valueForKeyPath:@"routes.legs.distance.text"] objectAtIndex:0]objectAtIndex:0];
    NSArray *arrDescription =[[[json valueForKeyPath:@"routes.legs.steps.html_instructions"] objectAtIndex:0] objectAtIndex:0];
    dictRouteInfo=[NSDictionary dictionaryWithObjectsAndKeys:totalDistance,@"totalDistance",totalDuration,@"totalDuration",arrDistance ,@"distance",arrDescription,@"description", nil];
    [self.btnDirection setEnabled:NO];
    if (dictRouteInfo) {
        [self.btnDirection setEnabled:YES];
    }
    NSArray* arrpolyline = [[[json valueForKeyPath:@"routes.legs.steps.polyline.points"] objectAtIndex:0] objectAtIndex:0]; //2
    double srcLat=[[[[json valueForKeyPath:@"routes.legs.start_location.lat"] objectAtIndex:0] objectAtIndex:0] doubleValue];
    double srcLong=[[[[json valueForKeyPath:@"routes.legs.start_location.lng"] objectAtIndex:0] objectAtIndex:0] doubleValue];
    double destLat=[[[[json valueForKeyPath:@"routes.legs.end_location.lat"] objectAtIndex:0] objectAtIndex:0] doubleValue];
    double destLong=[[[[json valueForKeyPath:@"routes.legs.end_location.lng"] objectAtIndex:0] objectAtIndex:0] doubleValue];
    CLLocationCoordinate2D sourceCordinate = CLLocationCoordinate2DMake(srcLat, srcLong);
    CLLocationCoordinate2D destCordinate = CLLocationCoordinate2DMake(destLat, destLong);

    [self addAnnotationSrcAndDestination:sourceCordinate :destCordinate andAdds:SourceAddress andDestinationAddress:DestinationAdds];
    //    NSArray *steps=[[aary objectAtIndex:0]valueForKey:@"steps"];

    //    replace lines with this may work

    NSMutableArray *polyLinesArray =[[NSMutableArray alloc]initWithCapacity:0];

    for (int i = 0; i < [arrpolyline count]; i++)
    {
        NSString* encodedPoints = [arrpolyline objectAtIndex:i] ;
        MKPolyline *route = [self polylineWithEncodedString:encodedPoints];
        [polyLinesArray addObject:route];
    }
    [self.mapShow addOverlays:polyLinesArray];
    self.mapShow.delegate = self;
    [self zoomToFitMapAnnotations:self.mapShow];
}else{
    [self.btnDirection setEnabled:NO];
    [self ShowAlert:@"didn't find direction"];
}
}
#pragma mark - add annotation on source and destination

-(void)addAnnotationSrcAndDestination :(CLLocationCoordinate2D )srcCord :(CLLocationCoordinate2D)destCord andAdds:(NSString*)SourceAddress andDestinationAddress:(NSString*)DestinationAdds
{
MKPointAnnotation *sourceAnnotation = [[MKPointAnnotation alloc]init];
MKPointAnnotation *destAnnotation = [[MKPointAnnotation alloc]init];
sourceAnnotation.coordinate=srcCord;
destAnnotation.coordinate=destCord;
sourceAnnotation.title=SourceAddress;
destAnnotation.title=DestinationAdds;
[self.mapShow addAnnotation:sourceAnnotation];
[self.mapShow addAnnotation:destAnnotation];
}

#pragma mark - decode map polyline

- (MKPolyline *)polylineWithEncodedString:(NSString *)encodedString {
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;

    if (coordIdx == count) {
        NSUInteger newCount = count + 10;
        coords = realloc(coords, newCount * sizeof(CLLocationCoordinate2D));
        count = newCount;
    }
}
MKPolyline *polyline = [MKPolyline polylineWithCoordinates:coords count:coordIdx];
free(coords);

return polyline;
}
#pragma mark - map overlay
-(MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id<MKOverlay>)overlay
{
MKPolylineRenderer *renderer = [[MKPolylineRenderer alloc] initWithOverlay:overlay];
renderer.strokeColor = [UIColor colorWithRed:155.0/255.0 green:89.0/255.0 blue:182.0/255.0 alpha:1.0];
renderer.lineWidth = 5.0;
return renderer;
}