iphone - 添加两个 MKPolylineView

Question

我无法在 MKOverlayView 中添加两个不同颜色的不同 MKPolylineView。关于如何实现这一目标的任何想法？谢谢

这是我的代码：

- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
{
MKOverlayView* overlayView = nil;
UIColor *mycolor;

self.routeLineView = [[[MKPolylineView alloc] initWithPolyline:self.routeLine] autorelease];

mycolor = [UIColor colorWithRed:85.0/255.0 green:133.0/255.0 blue:255.0/255.0 alpha:0.6];
self.routeLineView.fillColor = mycolor;
self.routeLineView.strokeColor = mycolor;
self.routeLineView.lineWidth = 15;
[overlayView addSubview:self.routeLineView];

self.routeLineView2 = [[[MKPolylineView alloc] initWithPolyline:self.routeLine2] autorelease];
mycolor = [UIColor colorWithRed:85.0/255.0 green:19.0/255.0 blue:25.0/255.0 alpha:0.6];
self.routeLineView2.fillColor = mycolor;
self.routeLineView2.strokeColor = mycolor;
self.routeLineView2.lineWidth = 15;
[overlayView addSubview:self.routeLineView2];   

return overlayView;
}

Answer 1

viewForOverlay将为您添加到地图的每个叠加层单独调用该方法。因此，在该方法中，您只返回当前正在调用的叠加层的叠加层视图（即overlay参数）。

检查它正在为哪个叠加层请求视图，并仅为该叠加层创建和返回视图。

例如：

if (overlay == self.routeLine)
{
    //create and return overlay view for routeLine...
    //set color, etc...
    return self.routeLineView;
}
else
if (overlay == self.routeLine2)
{
    //create and return overlay view for routeLine2...
    //set color, etc...
    return self.routeLineView2;
}

return nil;

不要做任何事addSubview。只需创建覆盖视图并返回它。