Change the marker position by onClick google map ios - ios

Question

I'm using a google map in iPhone app by objective-c, it is ok and the marker is in a given location. I want when click on a specific location change the marker location to the selected location by clicking the map.
How to do this?
Thanks in advance.
my code:
GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:29.964996
longitude:30.939680 zoom:5
bearing:0
viewingAngle:0
];
_mapView = [GMSMapView mapWithFrame:viewOfMap.bounds camera:camera];
_mapView.autoresizingMask = UIViewAutoresizingFlexibleWidth|
UIViewAutoresizingFlexibleHeight;
[_mapView addObserver:self
forKeyPath:#"myLocation"
options:NSKeyValueObservingOptionNew
context:NULL];
[viewOfMap addSubview:_mapView];
dispatch_async(dispatch_get_main_queue(), ^{
//_mapView.myLocationEnabled = YES;
_mapView.myLocationEnabled = YES;
});
GMSMarker *marker = [[GMSMarker alloc] init];
marker.position = CLLocationCoordinate2DMake(lat, lag);
marker.map = _mapView;

Answer 1

- (BOOL)mapView:(GMSMapView *)mapView didTapMarker:(GMSMarker *)marker
{
marker.icon=[UIImage imageNamed:#"selectedicon.png"];//selected marker
for (int i=0; i<[markerArray count]; i++)
{
GMSMarker *unselectedMarker=markerArray[i];
//check selected marker and unselected marker position
if(unselectedMarker.position.latitude!=marker.position.latitude && unselectedMarker.position.longitude!=marker.position.longitude)
{
unselectedMarker.icon=[UIImage imageNamed:#"unselectedicon.png"];
}
}
return NO;
}

Answer 2

If I understand your question, you want to tap a location and have a marker move to that location.
Be sure that your view controller implements GMSMapViewDelegateand use the didTapAtCoordinate delegate method. Something like this:
-(void)mapView:(GMSMapView *)mapView didTapAtCoordinate:(CLLocationCoordinate2D)coordinate {
[marker setPosition:coordinate];
}