mac android创建activity 空指针,扩展BaseActivity，在super.oncreate上显示空指针

BaseActivity.java

public class BaseActivity extends Activity{

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

DMCApplication.getInstance().addActivity(this);

}

@Override

protected void onDestroy() {

DMCApplication.getInstance().removeActivity(this);

super.onDestroy();

}

}

SplashScreenActivity.java

public class SplashScreenActivity extends BaseActivity {

private Handler handler = new Handler();

private static final int sDelayTime = 2000;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_splash_screen);

startService();

handler.postDelayed(new Runnable() {

@Override

public void run() {

startMainActivity();

}

}, sDelayTime);

}

private void startMainActivity() {

Intent intent = new Intent(getApplicationContext(), MainActivity.class);

startActivity(intent);

finish();

}

private void startService() {

}

}

DMCApplication.java

public class DMCApplication extends Application {

private static DMCApplication mDmcApplication;

private List activities;

public ControlPoint mControlPoint;

@Override

public void onCreate() {

super.onCreate();

if (activities != null) {

activities = null;

}

activities = new ArrayList();

mDmcApplication = this;

}

public void addActivity(Activity activity) {

if (activities != null) {

if (activities.contains(activity)) {

activities.remove(activity);

}

activities.add(activity);

}

}

public void removeActivity(Activity activity) {

if (activities != null && activities.contains(activity)) {

activities.remove(activity);

}

}

public static DMCApplication getInstance() {

return mDmcApplication;

}

public void quit() {

if (activities != null) {

for (Activity activity : activities) {

activity.finish();

}

activities = null;

}

}

public void setControlPoint(ControlPoint controlPoint) {

mControlPoint = controlPoint;

}

public ControlPoint getControlPoint() {

return mControlPoint;

}

}

logcat的

java.lang.RuntimeException：无法启动活动ComponentInfo {com.abc.xyx / com.abc.xyx.actvities.SplashScreenActivity}：

java.lang.NullPointerException：尝试在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2946)上的空对象引用上调用虚方法'void com.abc.xyx.DMCApplication.addActivity(android.app.Activity)'在Android.app.A活动中的android.app.A活动时，Android.A.运行时，Android.A.运行时，Android.A.运行时，运行android.app.A活动时，运行android.app.A活动时，运行android.app.A活动android.app.Looper.loop(Looper.java:164)的os.Handler.dispatchMessage(Handler.java:105)位于android.app.ActivityThread.main(ActivityThread.java:6809)的java.lang.reflect.Method .invoke(Native Method)位于com.android.internal.os.Zygote $ MethodAndArgsCaller.run(Zygote.java:240)com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)引起：java .lang.NullPointerException：尝试在com.abc.xyx.actvities.B上的空对象引用上调用虚方法'void com.agileapps.dlnaupnp.DMCApplication.addActivity(android.app.Activity)' aseActivity.onCreate(BaseActivity.java:14)位于android.app.Instrumentation的android.app.Activity.performCreate(Activity.java:6998)的com.abc.xyx.actvities.SplashScreenActivity.onCreate(SplashScreenActivity.java:22) .callActivityOnCreate(Instrumentation.java:1230)在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2899)