|
当我们获取了一组地理位置后，可能会想要在地图上绘制这组地理位置信息所包含的路线。
MKMapView提供了addOverlay功能（以及addAnnotation），让我们可以在地图上放一层遮罩。如果要放一组遮罩，可以用addOverlays。
-
#pragma mark -
-
-
- (void)drawLineWithLocationArray:(NSArray *)locationArray
-
{
-
int pointCount = [locationArray count];
-
CLLocationCoordinate2D *coordinateArray = (CLLocationCoordinate2D *)malloc(pointCount * sizeof(CLLocationCoordinate2D));
-
-
for (int i = 0; i < pointCount; ++i) {
-
CLLocation *location = [locationArray objectAtIndex:i];
-
coordinateArray[i] = [location coordinate];
-
}
-
-
self.routeLine = [MKPolyline polylineWithCoordinates:coordinateArray count:pointCount];
-
[self.mapView setVisibleMapRect:[self.routeLine boundingMapRect]];
-
[self.mapView addOverlay:self.routeLine];
-
-
free(coordinateArray);
-
coordinateArray = NULL;
-
}
MKPolyLine为我们提供了方便绘制多条线段的功能，它实现了MKOverlay协议，但并不能作为遮罩。我们需要实现相应的遮罩代理方法：
-
#pragma mark - MKMapViewDelegate
-
-
- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id<MKOverlay>)overlay
-
{
-
if(overlay == self.routeLine) {
-
if(nil == self.routeLineView) {
-
self.routeLineView = [[[MKPolylineView alloc] initWithPolyline:self.routeLine] autorelease];
-
self.routeLineView.fillColor = [UIColor redColor];
-
self.routeLineView.strokeColor = [UIColor redColor];
-
self.routeLineView.lineWidth = 5;
-
}
-
return self.routeLineView;
-
}
-
return nil;
-
}
下面是我的测试代码，用北京的经纬度和杭州的经纬度画线：
-
- (void)drawTestLine
-
{
-
CLLocation *location0 = [[CLLocation alloc] initWithLatitude:39.954245 longitude:116.312455];
-
CLLocation *location1 = [[CLLocation alloc] initWithLatitude:30.247871 longitude:120.127683];
-
NSArray *array = [NSArray arrayWithObjects:location0, location1, nil];
-
[self drawLineWithLocationArray:array];
-
}
| 
转播
