相关疑难解决方法(0)

我做了一个演示项目(来自github上的Moving-MKAnnotationView演示),用于在地图上移动汽车以下是它的链接

https://github.com/pratikbhiyani/Moving-MKAnnotationView

我在vinaut的给定答案的基础上编辑我的代码,但问题是,当我们缩放或滚动地图动画时,在我们缩放或滚动地图注释设置为其原始角度一段时间时,在ios 7和ios 6中分散注意力.

下面是我的演示项目的屏幕截图

这是我改变的一些代码

- (void) setPosition : (id) posValue;
{
    NSLog(@"set position");

    //extract the mapPoint from this dummy (wrapper) CGPoint struct
    MKMapPoint mapPoint = *(MKMapPoint*)[(NSValue*)posValue pointerValue];

    CLLocationCoordinate2D coord = MKCoordinateForMapPoint(mapPoint);
    CGPoint toPos;
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7) {

        toPos = [self.mapView convertCoordinate:coord toPointToView:self.mapView];
    }
    else
    {
        CGFloat zoomFactor =  self.mapView.visibleMapRect.size.width / self.mapView.bounds.size.width;
        toPos.x = mapPoint.x/zoomFactor;
        toPos.y = mapPoint.y/zoomFactor;
    }



    [self setTransform:CGAffineTransformMakeRotation([self getHeadingForDirectionFromCoordinate:MKCoordinateForMapPoint(previousPoint) toCoordinate: MKCoordinateForMapPoint(mapPoint)])];

    if (MKMapRectContainsPoint(self.mapView.visibleMapRect, mapPoint)) {

        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"]; …

我有一个可以快速更新的注释数据集.目前我删除所有注释,然后将它们重新绘制回地图上.

NSArray *existingpoints = [mapView.annotations filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"!(self isKindOfClass: %@)", [MKUserLocation class]]];
[mapView removeAnnotations:existingpoints];

我在自定义对象中计算它们的位置,因此希望能够调用它并"移动"注释而不删除并将其重新添加回地图.我制作的示例调用工作,我想几乎"民意调查"在下面.

- (CLLocationCoordinate2D) coordinate
{
    CLLocationCoordinate2D coord;
    coord.latitude = [lat doubleValue];
    coord.longitude = [lon doubleValue];


        double differencetime = exampleTime;
        double speedmoving;
        double distanceTravelled = speedmoving * differencetime;

        CLLocationDistance movedDistance = distanceTravelled;
        double radiansHeaded = DEG2RAD([self.heading doubleValue]);
        CLLocation *newLocation = [passedLocation newLoc:movedDistance along:radiansHeaded];
        coord = newLocation.coordinate;

    return coord;
}

根据要求,Object的.h文件,我没有SetCoordinate方法..

#import <Foundation/Foundation.h>
#import <CoreLocation/CoreLocation.h>
#import <MapKit/MapKit.h>

@interface TestObject : NSObject <MKAnnotation>{
    NSString *adshex;
    NSString *lat;
    NSString *lon;


    NSString …

我有一个从MKOverlayPathView继承的地图自定义视图.我需要这个自定义视图来显示圆,线和文本.

我已经设法使用路径绘制CGPathAddArc和CGPathAddLineToPoint函数绘制圆和线.

但是,我仍然需要添加文字.

我尝试使用添加文本

 [text drawAtPoint:centerPoint withFont:font];

但我得到了无效的上下文错误.

任何的想法？