我用MKMapRectMake
标记东北和西南来显示一个区域。我是这样做的:
routeRect = MKMapRectMake(southWestPoint.x, southWestPoint.y, northEastPoint.x - southWestPoint.x, northEastPoint.y - southWestPoint.y);
[self.mapView setVisibleMapRect:routeRect];
设置好这个显示区域后,怎样才能把地图缩小一点呢?做这个的最好方式是什么?
更新
这是我用来获取rect
功能的代码setVisibleMapRect
:
for(Path* p in ar)
{
self.routeLine = nil;
self.routeLineView = nil;
// while we create the route points, we will also be calculating the bounding box of our route
// so we can easily zoom in on it.
MKMapPoint northEastPoint;
MKMapPoint southWestPoint;
// create a c array of points.
MKMapPoint* pointArr = malloc(sizeof(CLLocationCoordinate2D) * ar.count);
for(int idx = 0; idx < ar.count; idx++)
{
Path *m_p = [ar objectAtIndex:idx];
[NSCharacterSet characterSetWithCharactersInString:@","]];
CLLocationDegrees latitude = m_p.Latitude;
CLLocationDegrees longitude = m_p.Longitude;
// create our coordinate and add it to the correct spot in the array
CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitude, longitude);
MKMapPoint point = MKMapPointForCoordinate(coordinate);
// adjust the bounding box
// if it is the first point, just use them, since we have nothing to compare to yet.
if (idx == 0) {
northEastPoint = point;
southWestPoint = point;
}
else
{
if (point.x > northEastPoint.x)
northEastPoint.x = point.x;
if(point.y > northEastPoint.y)
northEastPoint.y = point.y;
if (point.x < southWestPoint.x)
southWestPoint.x = point.x;
if (point.y < southWestPoint.y)
southWestPoint.y = point.y;
}
pointArr[idx] = point;
}
// create the polyline based on the array of points.
self.routeLine = [MKPolyline polylineWithPoints:pointArr count:ar.count];
_routeRect = MKMapRectMake(southWestPoint.x, southWestPoint.y, northEastPoint.x - southWestPoint.x, northEastPoint.y - southWestPoint.y);
// clear the memory allocated earlier for the points
free(pointArr);
[self.mapView removeOverlays: self.mapView.overlays];
// add the overlay to the map
if (nil != self.routeLine) {
[self.mapView addOverlay:self.routeLine];
}
// zoom in on the route.
[self zoomInOnRoute];
}