更改Google Maps iOS SDK的默认位置

Question

it is my first time to use google map and i asked to let the user choose the location that he wanted to point by taping on the map. when the application start it will point on the device location how the user will change it to the location he wants?

Answer 1

First get the point of user's tap. Then, get coordinate value for that CGPoint and set it as mapView's center.

-(void)handlePan:(UIPanGestureRecognizer *)recognizer
{
    // Get tap point
    CGPoint tapPoint = [recognizer locationInView:[recognizer superView]];

    // Convert CGPoint to CLLocationCoordinate2D
    CLLocationCoordinate2D center = [self.mapView.projection coordinateForPoint:tapPoint];

    // Set camera of mapView
    GMSCameraPosition * camera = [GMSCameraPosition cameraWithLatitude:center.latitude longitude:center.longitude zoom:self.mapView.camera.zoom];
    [self.mapView setCamera:camera];
}

Answer 2

或者，您可以实现GMSMapViewDelegate并使用- mapView:didTapAtCoordinate:方法。

Answer 3

You can move the view port by doing something similar like this to move the center point of map view

GMSCameraPosition *sydney = [GMSCameraPosition cameraWithLatitude:-33.8683
                                                        longitude:151.2086
                                                             zoom:6];
[mapView_ setCamera:sydney];

(Google Map SDK called it camera position, as if you use a camera to target a portion of the whole map)

Checkout https://developers.google.com/maps/documentation/ios/views?hl=en Moving the camera section

So here, in order to finish your task with move use to the point where he tapped. You'll need to do following steps:

1. define a iVar or property to keep record of the tap point location(lat/lng):

   CLLocationCoordinate2D *currentTapLocation;

2. In didTapAtCoordinate delegate, fetch that position

    - (void) mapView:(GMSMapView *) mapView didTapAtCoordinate:(CLLocationCoordinate2D) coordinate{ currentTapLocation = coordinate; } 

3. Create a GMSCamera and set camera to currentTapLocation

    - (void) mapView:(GMSMapView *) mapView didTapAtCoordinate:(CLLocationCoordinate2D) coordinate{ currentTapLocation = coordinate; GMSCameraPosition *newCameraPosition = [GMSCameraPosition cameraWithLatitude:currentTapLocation.latitude longitude:currentTapLocation.longitude zoom:6]; [mapView_ setCamera:newCameraPosition]; } 

4. Optional step: if you want animate to the new position instead setCamera directly, you can do:

   [mapView_ animateWithCameraUpdate:[mapView_ setCamera:newCameraPosition];];

   instead of

   [mapView_ setCamera:newCameraPosition];