Objective c 如何在google map sdk iOS中绘制从一个地方到另一个地方的路径？

我需要在谷歌地图中找到从一个地方到另一个地方的路径。如何使用google map sdk iOS绘制方向图

你们中的任何一个都能给出源代码。然后解释如何实现这一点

下面我还附上了图片，我需要在iPhone应用程序中使用谷歌地图SDK iOS实现这一点。

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谢谢，

我希望这会对你有所帮助。这是来自谷歌api。绘制多段线，并在其中指定长度为lat的路径

-（无效）showRoute:（id）routeDict{
NSString*pointStr=[[[routeDict objectForKey:@“routes”]objectAtIndex:0]objectForKey:@“overview_polyline”]objectForKey:@“points”]；
浮动最大长度=0.0；
浮动最小长度=0.0；
浮动最大值=0.0；
浮动最小值=0.0；
NSMutableArray*routeArr=[自解码多段线：pointStr]；
CLLocationCoordinate2D通勤点坐标[[routeArr count]]；
CLLocation*loc；
如果（[routeArr计数]）{
loc=[routeArr对象索引：0]；
最大长度=位置坐标经度；
min_long=位置坐标经度；
最大纬度=位置坐标纬度；
最小纬度=位置坐标纬度；
}
对于（int i=0；i max_lat）{
最大纬度=位置坐标纬度；
}
如果（位置坐标纬度<最小纬度）{
最小纬度=位置坐标纬度；
}
如果（位置坐标经度>最大长度）{
最大长度=位置坐标经度；
}
if（位置坐标经度<最小长度）{
min_long=位置坐标经度；
}
}
MKPolyline*overflowRoutePolygon=[MKPolyline polyline-polylineWithCoordinates:communierlotcoords count:[routeArr count]]；
[mapView addOverlay:overflowRoutePolygon]；
//NSLog（@“%f%f%f%f”、最小纬度、最大纬度、最小长度、最大长度）；
如果（max|u lat==0.0 | | min|u lat==0.0 | | max|u long==0.0 | | min|u long==0.0）{
}否则{
//计算地图中心
浮动中心长度=（最大长度+最小长度）/2；
浮动中心高度=（最大高度+最小高度）/2；
//计算三角洲
浮动增量=最大值-最小值+.00032；
浮动增量=最大长度-最小长度+0.00032；
//NSLog（@“%f%f%f”、中纬度、中长、德尔塔拉特、德尔塔隆）；
//创建新区域并设置地图
ClLocationCoordinated2D堇酸盐；
cordinate.纬度=中心纬度；
cordinate.longitude=中心长度；
MKCoordinateSpan=MKCoordinateSpanMake（deltaLat，deltaLong）；
MKCoordinateRegion={cordinate，span}；
[地图视图设置区域：区域]；
}
}
-（无效）展示路线
{
NSAutoreleasePool*池=[[NSAutoreleasePool alloc]init]；
浮动源LAT=0.00；
浮动源长=0.00；
浮动目标=0.00；
浮动目标长=0.00；
id记录=[routeArray对象索引：selectedIndex]；
sourceLat=[[[record objectForKey:@“To”]objectForKey:@“Latitude”]objectForKey:@“text”]floatValue]；
sourceLong=[[[record objectForKey:@“To”]objectForKey:@“经度”]objectForKey:@“text”]floatValue]；
destinationLat=[[[record objectForKey:@“From”]objectForKey:@“Latitude”]objectForKey:@“text”]floatValue]；
destinationLong=[[[record objectForKey:@“From”]objectForKey:@“经度”]objectForKey:@“text”]floatValue]；
如果（sourceLat==0.00 | | sourceLong==0.00 | | destinationLat==0.00 | | destinationLong==0.00）{
UIAlertView*警报=[[UIAlertView alloc]initWithTitle:@“方向错误”
消息：@“您的一个目的地无效。”
代表：赛尔夫
取消按钮：@“确定”
其他按钮：无]；
[警报显示]；
[警报发布]；
返回；
}
NSString*urlStr=[NSString stringWithFormat:@]http://maps.googleapis.com/maps/api/directions/json?origin=%f，%f&目标=%f，%f&传感器=false“，
sourceLat，sourceLong，
目的地，目的地长]；
NSLog（@“urlStr:%@”，urlStr）；
NSData*data=[[NSData alloc]initWithContentsOfURL:[NSURL URLWithString:urlStr]]；
//NSLog（@“方向响应：%@，[[NSString alloc]initWithData:数据编码：NSUTF8StringEncoding]）；
JSONDecoder*JSONKITDEXCODER=[JSONDecoder]；
NSMutableDictionary*RouteDigic=[[JSONKITDecommer objectWithData:data]copy]；
如果（！[[routeDic objectForKey:@“状态”]uppercaseString]IseQualtString:@“确定”]）{
UIAlertView*警报=[[UIAlertView alloc]initWithTitle:@“方向错误”
消息：@“无法从默认位置找到方向。”
代表：赛尔夫
取消按钮：@“确定”
其他按钮：无]；
[警报显示]；
[警报发布]；
[池释放]；
返回；
}
[self-performSelectorOnMainThread:@selector（showRoute:）with object:routeDic waitUntilDone:YES]；
[池释放]；
返回；
}
-（NSMutableArray*）解码多段线：（NSString*）编码器
{
NSMutableString*encoded=[[NSMutableString alloc]initWithCapacity:[EncodedStrength]]；
[encoded appendString:encodedStr]；
[encoded replaceCurrencesofString:@“\\\\”和字符串：@“\\\”选项：NSLiteralSearch范围：NSMakerRange（0，[编码长度]）；
NSInteger len=[编码长度]；
NSInteger指数=0；
NSMutableArray*数组=[[[NSMutableArray alloc]init]autorelease]；
NSInteger-lat=0；
NSInteger液化天然气=0；
while（指数-(void)showRoute:(id)routeDict {
    NSString *pointStr = [[[[routeDict objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"overview_polyline"] objectForKey:@"points"];

    float max_long = 0.0;
    float min_long = 0.0;

    float max_lat = 0.0;
    float min_lat = 0.0;

    NSMutableArray *routeArr = [self decodePolyLine:pointStr];
    CLLocationCoordinate2D commuterLotCoords[[routeArr count]];
    CLLocation *loc;
    if ([routeArr count]) {
        loc = [routeArr objectAtIndex:0];
        max_long = loc.coordinate.longitude;
        min_long = loc.coordinate.longitude;

        max_lat = loc.coordinate.latitude;
        min_lat = loc.coordinate.latitude;
    }

    for (int i=0; i<[routeArr count]; i++) {
        CLLocation *loc = [routeArr objectAtIndex:i];
        commuterLotCoords[i] = loc.coordinate;

        if (loc.coordinate.latitude > max_lat) {
            max_lat = loc.coordinate.latitude;
        }
        if (loc.coordinate.latitude < min_lat) {
            min_lat = loc.coordinate.latitude;
        }


        if (loc.coordinate.longitude > max_long) {
            max_long = loc.coordinate.longitude;
        }
        if (loc.coordinate.longitude < min_long) {
            min_long = loc.coordinate.longitude;
        }




    }

    MKPolyline *overflowRoutePolygon = [MKPolyline polylineWithCoordinates:commuterLotCoords count:[routeArr count]];

    [mapView addOverlay:overflowRoutePolygon];

    //NSLog(@"%f %f %f %f",min_lat,max_lat,min_long,max_long);
    if ( max_lat == 0.0 || min_lat == 0.0 || max_long == 0.0 || min_long == 0.0 ) {
    } else {
        //calculate center of map
        float center_long = (max_long + min_long) / 2;
        float center_lat = (max_lat + min_lat) / 2;

        //calculate deltas
        float deltaLat = max_lat - min_lat + .00032;
        float deltaLong = max_long - min_long + .00032;
        //NSLog(@"%f %f %f %f",center_lat,center_long,deltaLat,deltaLong);

        //create new region and set map
        CLLocationCoordinate2D cordinate;
        cordinate.latitude = center_lat;
        cordinate.longitude = center_long;
        MKCoordinateSpan span = MKCoordinateSpanMake(deltaLat, deltaLong);
        MKCoordinateRegion region = {cordinate, span};
        [mapView setRegion:region];
    }
}

-(void)showRoute 
{

    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    float sourceLat = 0.00;
    float sourceLong = 0.00;
    float destinationLat = 0.00;
    float destinationLong = 0.00;
    id record = [routeArray objectAtIndex:selectedIndex];
    sourceLat = [[[[record objectForKey:@"To"] objectForKey:@"Latitude"] objectForKey:@"text"] floatValue];
    sourceLong =  [[[[record objectForKey:@"To"] objectForKey:@"Longitude"] objectForKey:@"text"] floatValue];

    destinationLat = [[[[record objectForKey:@"From"] objectForKey:@"Latitude"] objectForKey:@"text"] floatValue];
    destinationLong =  [[[[record objectForKey:@"From"] objectForKey:@"Longitude"] objectForKey:@"text"] floatValue];

    if ( sourceLat == 0.00 || sourceLong == 0.00 || destinationLat == 0.00 || destinationLong == 0.00 ) {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Direction Error"
                                                        message: @"One of your destination is not valid."
                                                       delegate: self
                                              cancelButtonTitle: @"OK"
                                              otherButtonTitles: nil];
        [alert show];
        [alert release];
        return;
    }

    NSString *urlStr = [NSString stringWithFormat: @"http://maps.googleapis.com/maps/api/directions/json?origin=%f,%f&destination=%f,%f&sensor=false",
                        sourceLat, sourceLong,
                        destinationLat,destinationLong];
    NSLog(@"urlStr : %@",urlStr);
    NSData *data = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:urlStr]];
    //NSLog(@"direction response : %@",[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);

    JSONDecoder *jsonKitDecoder = [JSONDecoder decoder];
    NSMutableDictionary *routeDic = [[jsonKitDecoder objectWithData:data] copy];
    if ( ![[[routeDic objectForKey:@"status"] uppercaseString] isEqualToString:@"OK"] ) {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Direction Error"
                                                        message: @"Not able to find direction from your default location."
                                                       delegate: self
                                              cancelButtonTitle: @"OK"
                                              otherButtonTitles: nil];
        [alert show];
        [alert release];
        [pool release];
        return;
    }

    [self performSelectorOnMainThread:@selector(showRoute:) withObject:routeDic waitUntilDone:YES];

    [pool release];
    return;
}

-(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] 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 *latitute = [[[NSNumber alloc] initWithFloat:lat * 1e-5] autorelease];
        NSNumber *longitute = [[[NSNumber alloc] initWithFloat:lng * 1e-5] autorelease];
        CLLocation *loc = [[[CLLocation alloc] initWithLatitude:[latitute floatValue] longitude:[longitute floatValue]] autorelease];

        [array addObject:loc];
    }
    [encoded release];
    return array;
}

- (MKAnnotationView *)mapView:(MKMapView *)map viewForAnnotation:(id <MKAnnotation>)annotation


{
    HAnnotation *ann = (HAnnotation *)annotation;
    static NSString *AnnotationViewID = @"annotationViewID";

    HAnnotationView *annotationView = (HAnnotationView *)[map dequeueReusableAnnotationViewWithIdentifier:AnnotationViewID];
    if (annotationView == nil)
    {
        annotationView = [[[HAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:AnnotationViewID type:ann.type] autorelease];

    } 
    annotationView.type = ann.type;
    annotationView.annotation = annotation;
    [annotationView setNeedsDisplay];
    return annotationView;
}

- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views

{


    MKAnnotationView *aV;
    for (aV in views) {
        MKAnnotationView* annotationView = aV;
        annotationView.canShowCallout = NO;
    }
}



- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id < MKOverlay >)overlay

{


    if( [overlay isKindOfClass:[MKPolyline class]] ) {
        MKPolylineView *view = [[MKPolylineView alloc] initWithOverlay:overlay];
        view.lineWidth=2;
        view.strokeColor=[UIColor blueColor];
        view.fillColor=[[UIColor blueColor] colorWithAlphaComponent:0.5];
        return [view autorelease];
    } else {
        MKPolygonView *view = [[MKPolygonView alloc] initWithOverlay:overlay];
        view.lineWidth=2;
        view.strokeColor=[UIColor yellowColor];
        view.fillColor=[[UIColor yellowColor] colorWithAlphaComponent:0.3];
        return [view autorelease];
    }
    return nil;
}