how to display all PlaceMarks/pins on google map in iphone?

friends,

i a开发者_运维百科m new to iphone development and just implement google map in iphone application. now i am facing a problem with following description

i have list of latitude and longitude values when display them on map those pins are displayed on different locations.

now i want to set zoom level so that all pins are displayed on the screen.

any help would be appreciated.

If you're using an MKMapView you can use the setRegion:animated: method to change the region displayed. I would use annotationsInMapRect: to determine which annotations are being shown. Since annotationsInMapRect: returns an NSSet you could make an NSSet of all your annotations, and zoom out the MKMapView until the NSSet returned from annotationsInMapRect: matches your NSSet of all annotations.

The values 3.0 and 2.0 are only examples you can increase or decrease the values according to your requirement(how much you have to zoom) ,map is my mkmapview object

        MKCoordinateSpan span; 
        span.latitudeDelta = 3.0;
        span.longitudeDelta = 2.0;
        MKCoordinateRegion region;      
        region.span = span;     
        [map setRegion:region animated:YES];
        [map regionThatFits:region];