Question

我正在订阅获取推送坐标的数据流，每次听众获得新点时，我都想在地图上放置一个标记。如何将drawMarker代码放在正确的线程或正确的范围内？

@Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        enableMyLocation();
        subscribe();
    }

    public void drawLatestPoint(LatLng p) {
        System.out.println(p);
        mMap.addMarker(new MarkerOptions().position(p).title("Marker in Sydney"));
    }

    private void subscribe(){
        pubNub.subscribe()
                .channels(Arrays.asList("my_channel")) // subscribe to channel groups
                .execute();

        pubNub.addListener(new SubscribeCallback() {

            @Override
            public void message(PubNub pubnub, PNMessageResult message) {
                if (message.getMessage().get("lat") != null && message.getMessage().get("lng") != null) {
                    double lat = message.getMessage().get("lat").doubleValue();
                    double lng = message.getMessage().get("lng").doubleValue();
                    LatLng point = new LatLng(lat,lng);
                    drawLatestPoint(point);
                }
            }
        });
    }

Answer 1

您可以使用runOnUiThread在GUI线程中运行代码：

runOnUiThread(new Runnable() {
    @Override
    public void run() {
       // Your code to run in GUI thread here
    }
});

Answer 2

确保您的pubsub可以访问Context对象（可以是Application上下文或Service上下文）。然后将所需的代码放在run方法中：

// Get a handler that can be used to post to the main thread
Handler mainHandler = new Handler(context.getMainLooper());

Runnable myRunnable = new Runnable() {
    @Override 
    public void run() {....} // This is your code
};
mainHandler.post(myRunnable);

Reference

Android添加地图标记错误：java.lang.IllegalStateException：不在主线程上

2 个答案: