我如何在谷歌地图ios

Question

我使用谷歌地图SDK，我必须在用户移动时绘制折线，目前它只是动画标记，在针移动到特定位置之前绘制的路径。我必须同时画路径和移动别针。

观看此视频：https://www.dropbox.com/s/q5kdjf4iq0337vg/Map_Sample.mov?dl=0

这是我的代码

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        let location = locations.last!
        userPath.addCoordinate(location.coordinate) //userPath -> GMSMutablePath
        let polyline = GMSPolyline(path: userPath)
        polyline.strokeColor = UIColor(red: 0, green: 191/255.0, blue: 1, alpha: 0.8)
        polyline.strokeWidth = 5
        CATransaction.begin()
        CATransaction.setAnimationDuration(2.0)
        self.userMarker.position = location.coordinate
        self.userMarker.rotation = location.course
        polyline.map = self.googleMapView
        CATransaction.commit()
    }

此处还有截图，它现在是如何运作的

Answer 1

我也在尝试类似的事情（https://youtu.be/jej2XTwRQy8）。

尝试以多种方式制作GMSPolyline路径动画，但未能直接为其制作动画。

我怎么能找到替代方法呢？你所做的只是创建一个带有BreizerPath的CAShapeLayer，假装它看起来像GMSPolyline并为strokeEnd设置动画。动画完成后，显示实际的GMSPolyline并删除CAShapelayer。但是我必须优化它。

为了创建一个CAShapeLayer，以及起点，行，你可以参考下面的代码。

-(CAShapeLayer *)layerFromGMSMutablePath:(GMSMutablePath *)path{
    UIBezierPath *breizerPath = [UIBezierPath bezierPath];

    CLLocationCoordinate2D firstCoordinate = [path coordinateAtIndex:0];
    [breizerPath moveToPoint:[_mapView.projection pointForCoordinate:firstCoordinate]];

    for(int i=1; i<path.count; i++){
        CLLocationCoordinate2D coordinate = [path coordinateAtIndex:i];
        [breizerPath addLineToPoint:[_mapView.projection pointForCoordinate:coordinate]];
    }

    CAShapeLayer *shapeLayer = [CAShapeLayer layer];
    shapeLayer.path = [[breizerPath bezierPathByReversingPath] CGPath];
    shapeLayer.strokeColor = [[UIColor whiteColor] CGColor];
    shapeLayer.lineWidth = 4.0;
    shapeLayer.fillColor = [[UIColor clearColor] CGColor];
    shapeLayer.lineJoin = kCALineJoinRound;
    shapeLayer.lineCap = kCALineCapRound;
    shapeLayer.cornerRadius = 5;

    return shapeLayer;
}

以下是动画的代码。

-(void)animatePath:(CAShapeLayer *)layer{
    CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
    pathAnimation.duration = 3;
    pathAnimation.delegate = self;
    [pathAnimation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut]];
    pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
    pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];
    [layer addAnimation:pathAnimation forKey:@"strokeEnd"];
}

在我的情况下，我必须为整个路线制作动画。在您的情况下，您只需要为更新的部分设置动画。