android - 将 textview 的值设置为 Awareness.SnapshotApi.getWeather

Question

我想将我的 textView 的值设置为块Awareness.SnapshotApi.getWeather外，但它不起作用。每次我在标记区域设置值时程序崩溃。我也想知道，我怎样才能getWeather()从另一个班级/活动中打电话？

public class MainActivity extends AppCompatActivity {
private static final String TAG = "Awareness";
private GoogleApiClient mGoogleApiClient;
private TextView tv;
public int[] con;
private String[] conditions = {"Unknown", "Clear", "Cloudy", "Foggy", "Hazy", "Icy","Rainy", "Snowy", "Stromy","Wind"};
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    tv = (TextView) findViewById(R.id.textView);
    mGoogleApiClient = new GoogleApiClient.Builder(MainActivity.this)
            .addApi(Awareness.API)
            .build();
    mGoogleApiClient.connect();
    initSnapshots();

}

public void initSnapshots() {
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

        tv.setText("Permission failed");
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    Awareness.SnapshotApi.getWeather(mGoogleApiClient)
            .setResultCallback(new ResultCallback<WeatherResult>() {
                @Override
                public void onResult(@NonNull WeatherResult weatherResult) {
                    if (!weatherResult.getStatus().isSuccess()) {
                        tv.setText("weather failed");
                        return;
                    }
                    Weather weather = weatherResult.getWeather();
                    con = weather.getConditions();
                    tv.setText(conditions[con[0]] + "");
                }
            });
    //tv.setText(conditions[con[0]] + ""); (<---------Crushes if I declare here,Why?)
}
}