Question

我正在使用Mapkit框架进行项目。最初有佛罗里达州的地图，有许多注释和圆形叠加，显示哪些地区接收交付。我想拥有所有这些，以及MKPolygon来突出整个州。（通过使用所有坐标的XML文件和Objective-C中的XMLParser完成）

MKCircleView覆盖所有显示正常，我猜是因为它们都是相同的类型。但是，当我尝试实现MKPolygon视图时，它也不允许我这样做。

//Region for fort lauderdale delivery area overlay

MKCoordinateRegion fortLauderdale;
fortLauderdale.center.latitude = FTL_LATITUDE;
fortLauderdale.center.longitude = FTL_LONGITUDE;
fortLauderdale.span.latitudeDelta = SPAN_VALUE;
fortLauderdale.span.longitudeDelta = SPAN_VALUE;

//Create a circle for fort lauderdale area
MKCircle *fortLauderdaleCircle= [MKCircle circleWithCenterCoordinate:fortLauderdale.center radius:5000];
//2KM or 1.24 miles
[self.mapView addOverlay:fortLauderdaleCircle];

//Region for miami delivery area overlay

MKCoordinateRegion miami;
miami.center.latitude = MIA_LATITUDE;
miami.center.longitude = MIA_LONGITUDE;
miami.span.latitudeDelta = SPAN_VALUE;
miami.span.longitudeDelta = SPAN_VALUE;

//Create a circle for miami area
MKCircle *miamiCircle = [MKCircle circleWithCenterCoordinate:miami.center radius:5000];
//2KM or 1.24 miles
[self.mapView addOverlay:miamiCircle];

然后在实现它们的方法中我有这个：

-(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id<MKOverlay>)overlay
{
    MKCircleView *circleView = [[MKCircleView alloc]initWithCircle:overlay];
    circleView.fillColor = [[UIColor cyanColor] colorWithAlphaComponent:0.5];
    circleView.strokeColor =[[UIColor blueColor] colorWithAlphaComponent:0.6];
    circleView.lineWidth = 1 ;
    return circleView;

    //This is the code for the polygon view but I don't know how
    //to return it without run-time errors 
    //MKPolygonView *polygonView = [[MKPolygonView alloc] initWithPolygon:overlay];
    //polygonView.fillColor = [[UIColor greenColor] colorWithAlphaComponent:0.2];
    //polygonView.strokeColor = [[UIColor greenColor] colorWithAlphaComponent:0.6];
    //polygonView.lineWidth = 1;
    //return polygonView;
}

这已经看起来很糟糕，因为我在方法中调用了两个return语句，但那又是因为我问这个问题的原因。我不认为错误是我解析XML数据的方式，因为在执行它之前没有错误。谢谢

Answer 1

首先，我想指出您使用的是弃用方法。在iOS7中已弃用MKOverlayView。除此之外，您需要做的是根据传递给委托的overlay参数确定要返回的覆盖类型。所以，如果我要修改你的代码，这就是我要做的：

-(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id<MKOverlay>)overlay
{
    if ([overlay isKindOfClass:[MKCircle class]]) {
        MKCircleView *circleView = [[MKCircleView alloc]initWithCircle:overlay];
        circleView.fillColor = [[UIColor cyanColor] colorWithAlphaComponent:0.5];
        circleView.strokeColor =[[UIColor blueColor] colorWithAlphaComponent:0.6];
        circleView.lineWidth = 1 ;
        return circleView;
    } else if ([overlay isKindOfClass:[MKPolygon class]]) {
        MKPolygonView *polygonView = [[MKPolygonView alloc] initWithPolygon:overlay];
        polygonView.fillColor = [[UIColor greenColor] colorWithAlphaComponent:0.2];
        polygonView.strokeColor = [[UIColor greenColor] colorWithAlphaComponent:0.6];
        polygonView.lineWidth = 1;
        return polygonView;
    }

    return nil;
}

使用Mapkit实现多个叠加层

1 个答案: