java - Android 对 if 语句的报警

Question

当遇到 if 语句时，我想发出警报并使用对话框按钮将其关闭。

googleMap.setOnInfoWindowClickListener(
    new OnInfoWindowClickListener() {
        public void onInfoWindowClick(Marker marker) {
            LatLng clickedMarkerLatLng = marker.getPosition();
            lat =  clickedMarkerLatLng.latitude;
            long1 =  clickedMarkerLatLng.longitude;
            String name = marker.getTitle();
            select=true;

            final Location markerLoc = new Location("");
            markerLoc.setLatitude(lat);
            markerLoc.setLongitude(long1);


            final Location location = locationManager.getLastKnownLocation(provider);   

            float distanceBetweenPoints = location.distanceTo(markerLoc);

            TextView t = (TextView) findViewById(R.id.tv_location);
            t.setText("Distance to "+ name +" is "+ distanceBetweenPoints/1000 + " km");

            if (distanceBetweenPoints<1000){
            TextView t2 = (TextView) findViewById(R.id.tv_location);
            t2.setText("ALARMALARMALARM");
            //alarm here

        }
    });

我发现的有关警报管理器的所有内容似乎都不允许我在 if 语句中使用它。我该怎么做呢？