视图左上角的 GMSMarker 图标 (iOS)

Question

I am trying to create a UITableViewCell containing a GMSMapView with a GMSMarker at the center of the current Position.

The problem is that the marker always appears at the top left corner of the current position and I don't know how to solve the problem.

I tried to follow these steps: Implementing a Google Map with UItableviewCell

here is my code from cellForRowAt:

let locationCell = tableView.dequeueReusableCell(withIdentifier: "activityLocationCell") as! ActivityLocationCell

let latitude = CLLocationDegrees(activity.coordinates![0])
let longitude = CLLocationDegrees(activity.coordinates![1])
let position = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)

locationCell.googleMapView.camera = GMSCameraPosition.camera(withTarget: position, zoom: 15)

let marker = GMSMarker(position: position)
marker.groundAnchor = CGPoint(x: 0.5, y: 0.5)
marker.map = locationCell.googleMapView

return locationCell

Here is a screenshot of my problem: marker is at the top left corner of the map

Answer 1

I had a pretty similar issue. I resolved it by changing the moment I configure the map in the view lifecycle.

In my case, I was using a child view controller. I was configuring the map before viewWillAppear was called which caused the map to not center properly (the marker was on the top left corner). I moved my call to after the viewWillAppear and it fixed it. A good place would be viewDidAppear .

If you are using a cell, you will probably need to investigate with the view lifecycle instead of the controller lifecycle.

This is not written anywhere on the Google documentation.

Answer 2

you have to draw map in func viewDidLayoutSubviews()

Answer 3

Try creating Marker when map is ready completely. for eg: use the delegate.

  var ifMapReady: Bool = false 
  ...
  ...
  func mapViewSnapshotReady(_ mapView: GMSMapView) {
        ifMapReady = true
  }
  //Call this method from where ever you want to load map
  func updateMap() {
       if ifMapReady {
            //Load Map
       }
  }

This delegate will be called multiple times(eg: map is swiped or moved etc) whenever the Map tiles are ready. So we can use a boolean value for understanding that map loaded successfully. Based on that value we can load the Map properly when initiating.

Answer 4

I want to add one more thing. @Gabriel Cartier's answer worked for me with one additional change in my code.

[self->mapView_ animateToCameraPosition:camera];  

And I replaced with

[self->mapView_ setCamera:camera];