我正在开发一个带有地图的应用程序,用户可以在其中绘制多边形区域。
我的问题是可以用结绘制多边形(见图)(我不知道结是否是正确的词)。我没有找到一种简单的方法来防止多边形打结。对于附加图像的情况,我希望去除小卷曲,甚至平滑轮廓
你知道一种方法吗?
在用户触摸屏幕时绘制多边形的过程确实使用了,MKPolyline
如下所示:MKPolygon
MKOverlay
- (void)touchesBegan:(UITouch*)touch
{
CGPoint location = [touch locationInView:self.mapView];
CLLocationCoordinate2D coordinate = [self.mapView convertPoint:location toCoordinateFromView:self.mapView];
[self.coordinates addObject:[NSValue valueWithMKCoordinate:coordinate]];
}
- (void)touchesMoved:(UITouch*)touch
{
CGPoint location = [touch locationInView:self.mapView];
CLLocationCoordinate2D coordinate = [self.mapView convertPoint:location toCoordinateFromView:self.mapView];
[self.coordinates addObject:[NSValue valueWithMKCoordinate:coordinate]];
}
- (void)touchesEnded:(UITouch*)touch
{
CGPoint location = [touch locationInView:self.mapView];
CLLocationCoordinate2D coordinate = [self.mapView convertPoint:location toCoordinateFromView:self.mapView];
[self.coordinates addObject:[NSValue valueWithMKCoordinate:coordinate]];
[self didTouchUpInsideDrawButton:nil];
}
- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
{
MKOverlayPathView *overlayPathView;
if ([overlay isKindOfClass:[MKPolygon class]])
{
// create a polygonView using polygon_overlay object
overlayPathView = [[MKPolygonView alloc] initWithPolygon:overlay];
overlayPathView.fillColor = [UIColor redColor];
overlayPathView.lineWidth = 1.5;
return overlayPathView;
}
else if ([overlay isKindOfClass:[MKPolyline class]])
{
overlayPathView = [[MKPolylineView alloc] initWithPolyline:(MKPolyline *)overlay];
overlayPathView.fillColor = [UIColor redColor];
overlayPathView.lineWidth = 3;
return overlayPathView;
}
return nil;
}