我想从另一个类调用TTS方法,所以我将TTSHelper命名为class,并添加了speak方法,但它不起作用 public class MainActivity extends, null); myTTS.speak(message, TextToSpeech.QUEUE_FLUSH, null);01-07 00:44:37.96
解决这个问题的更好方法是什么?: Attempt to invoke virtual method 'java.lang.String com.google.firebase.auth.FirebaseUser.getUid()'on a null object reference
at android.app.ActivityThread.handleBindApplication(ActivityThread.java: Attempt to invoke virtual meth
com.pctoolmanconsulting.trackmyweight, PID: 30184
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.startsWith(java.lang.String)' on a null