android - 找不到符号方法 getMap()

Question

private GoogleMap mMap;

我从 MainActivity 开始一个类似的 Activity :

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    int id = item.getItemId();

    if (id == R.id.nav_car) {
        Intent detailIntent = new Intent(this, Map_Activity.class);
        startActivity(detailIntent);
    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawerLayout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

一切正常，直到我得到 ( Error:(222, 97) error: Cannot find symbol method getMap() here:

private void setUpMap() {
    if (mMap == null) {
        mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        mMap.setMyLocationEnabled(true);
        mMap.setOnMyLocationChangeListener(this);

    }
}

请帮我解决这个问题!

Answer 1

使用SupportMapFragment的getMapAsync()

((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMapAsync(new OnMapReadyCallback() {
        @Override
        public void onMapReady(GoogleMap googleMap) {
            mMap  = googleMap;
        }
    });

您可以找到文档here