Question

How can I make a preview icon like in the iPhone Map application?

Screenshot http://img835.imageshack.us/img835/1619/img0016x.png

Is there a function for this?

Answer 1

In iOS 7 use MKMap​Snapshotter. From NSHipster:

MKMapSnapshotOptions *options = [[MKMapSnapshotOptions alloc] init];
options.region = self.mapView.region;
options.size = self.mapView.frame.size;
options.scale = [[UIScreen mainScreen] scale];

NSURL *fileURL = [NSURL fileURLWithPath:@"path/to/snapshot.png"];

MKMapSnapshotter *snapshotter = [[MKMapSnapshotter alloc] initWithOptions:options];
[snapshotter startWithCompletionHandler:^(MKMapSnapshot *snapshot, NSError *error) {
    if (error) {
        NSLog(@"[Error] %@", error);
        return;
    }

    UIImage *image = snapshot.image;
    NSData *data = UIImagePNGRepresentation(image);
    [data writeToURL:fileURL atomically:YES];
}];

---

Before iOS7 do one of the following:

• Add a live map and disable interaction.
• Use the Google Static Maps API (explained below).
• Create a MKMapView and render it to an image. I tried this (see previous edit) but couldn’t get the tiles to load. I tried calling needsLayout and other methods but didn’t work.

Apple’s deal with Google is more reliable than a free API, but on the bright side, it is really simple. Documentation is at http://code.google.com/apis/maps/documentation/staticmaps/

This is the minimum amount of parameters for practical use:
http://maps.googleapis.com/maps/api/staticmap?center=40.416878,-3.703530&zoom=15&size=290×179&sensor=false

A summary of the parameters:

• center: this can be an address, or a latitude,longitude pair with up to 6 decimals (more than 6 are ignored).
• format: png8 (default), png24, git, jpg, jpg-baseline.
• language: Use any language. Default will be used if requested wasn’t available.
• maptype: One of the following: roadmap, satellite, hybrid, terrain.
• scale: 1,2,4. Use 2 to return twice the amount of pixels on retina displays. 4 is restricted to premium customers.
  Non paid resolution limits are 640×640 for 1 and 2.
• sensor: true or false. Mandatory. It indicates if the user is being located using a device.
• size: size in pixels.
• zoom: 0 (whole planet) to 21.

There is a few more to add polygons, custom markers, and style the map.

  NSData* data = [NSData dataWithContentsOfURL:@"http://maps.googleap..."];
  UIImage *img = [UIImage imageWithData:data];