Ios4 地图视图的缩放

Mapview应以缩放模式启动特定pin。我们如何通过编程实现这一点。任何委托方法都可以做到这一点

MKMapView * mvMap;

MKCoordinateRegion region;
region.center.longitude = 0;
region.center.latitude = 0;
region.span.latitudeDelta = 5;  // this is zoom level
region.span.longitudeDelta = 5;

[mvMap setRegion:region animated:NO];
[mvMap regionThatFits:region];