Question

我正在尝试使用Extras将数据从ChronometerActivity发送到PlayerHomeActivity，但这是行不通的。

计时器活动：

public class ChronometerActivity extends AppCompatActivity {

@BindView(R.id.chronometer)
Chronometer chronometer;
@BindView(R.id.fab_play) FloatingActionButton fab_play;
@BindView(R.id.fab_pause) FloatingActionButton fab_pause;
@BindView(R.id.fab_stop) FloatingActionButton fab_stop;
@BindView(R.id.btn_player) Button btn_player;
@BindView(R.id.btn_golkeeper) Button btn_goolkeeper;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_chronometr);
    ButterKnife.bind(this);

    timeWhenStopped=0;
    ChronometerListener listener = new ChronometerListener(this);
    fab_play.setOnClickListener(listener);
    fab_pause.setOnClickListener(listener);
    fab_stop.setOnClickListener(listener);
    btn_player.setOnClickListener(listener);
    btn_goolkeeper.setOnClickListener(listener);

}

PlayerHomeActivity：

public class PlayerHomeActivity extends AppCompatActivity {

private int typePlayer = getIntent().getExtras().getInt("typePlayer");


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_player_home);

    BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
    PlayerHomeActivitylistener listener = new PlayerHomeActivitylistener(this);
    navigation.setOnNavigationItemSelectedListener(listener);

    .....
  }
}

ChronometerListener：

public class ChronometerListener implements View.OnClickListener {
ChronometerActivity activity;
public ChronometerListener(ChronometerActivity activity) {
    this.activity=activity;
}

@Override
public void onClick(View v) {
    String typePlayer;
    switch (v.getId()){

        case R.id.fab_play:
            activity.start(activity.getChronometer());
            break;
        case R.id.fab_stop:
            activity.stop(activity.getChronometer());
            break;
        case R.id.fab_pause:
            activity.pause(activity.getChronometer());
            break;
        case R.id.btn_player:
            typePlayer="0";
            Intent intent =new Intent(activity.getApplicationContext(), PlayerHomeActivity.class);

            intent.putExtra("typePlayer", typePlayer);
            activity.startActivity(intent);
            break;
        case R.id.btn_golkeeper:
            typePlayer="1";
            Intent intent2 = new Intent(activity.getApplicationContext(), PlayerHomeActivity.class);
            intent2.putExtra("typePlayer", typePlayer);
            activity.startActivity(intent2);
            break;

    }

}

我收到此错误：

E / Android运行时：致命异常：主要进程：simonerusso.it.beneventoscouting，PID：5963 java.lang.RuntimeException：无法实例化活动ComponentInfo {simonerusso.it.beneventoscouting / simonerusso.it.beneventoscouting.view.PlayerHomeActivity}： java.lang.NullPointerException：尝试调用虚拟方法 'android.os.Bundle android.content.Intent.getExtras（）'为null 对象参考在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2236）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2387）在android.app.ActivityThread.access $ 800（ActivityThread.java:151）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1303）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:135）在android.app.ActivityThread.main（ActivityThread.java:5254）在java.lang.reflect.Method.invoke（本机方法）在java.lang.reflect.Method.invoke（Method.java:372）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:903）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:698）引起原因：java.lang.NullPointerException：尝试调用虚拟方法'android.os.Bundle android.content.Intent.getExtras（）' 在空对象引用上在simonerusso.it.beneventoscouting.view.PlayerHomeActivity。（PlayerHomeActivity.java:116）在java.lang.reflect.Constructor.newInstance（本地方法）在java.lang.Class.newInstance（Class.java:1606）在android.app.Instrumentation.newActivity（Instrumentation.java:1066）在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2226）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2387）在android.app.ActivityThread.access $ 800（ActivityThread.java:151）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1303）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:135）在android.app.ActivityThread.main（ActivityThread.java:5254）在java.lang.reflect.Method.invoke（本机方法）在java.lang.reflect.Method.invoke（Method.java:372）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:903）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:698）

Answer 1

public class PlayerHomeActivity extends AppCompatActivity {


 @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_player_home);


 int typePlayer = getIntent().getExtras().getInt("typePlayer");

BottomNavigationView navigation = (BottomNavigationView) 
findViewById(R.id.navigation);
PlayerHomeActivitylistener listener = new PlayerHomeActivitylistener(this);
navigation.setOnNavigationItemSelectedListener(listener);

.....
   }
}

移动到oncreate（）内部的行下方

 int typePlayer = getIntent().getExtras().getInt("typePlayer");

Answer 2

您需要在Activity的getIntent().getExtras().getInt("typePlayer");内致电onCreate()

如何发送数据

2 个答案: