Osmdroid -NullPointerException：尝试调用虚拟方法'boolean org.osmdroid.views.overlay.Overlay.onTouchEvent
Osmdroid -NullPointerException: Attempt to invoke virtual method 'boolean org.osmdroid.views.overlay.Overlay.onTouchEvent
我的应用程序有问题，其中包括 osmdroid。每次我尝试 运行 设备上的应用程序并触摸地图时，应用程序都会崩溃，并且出现此错误：
2018-10-02 14:11:45.191 19645-19645/com.message_drop.messagedrop E/InputEventReceiver: Exception dispatching input event.
2018-10-02 14:11:45.191 19645-19645/com.message_drop.messagedrop E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback
2018-10-02 14:11:45.196 19645-19645/com.message_drop.messagedrop E/MessageQueue-JNI: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean org.osmdroid.views.overlay.Overlay.onTouchEvent(android.view.MotionEvent, org.osmdroid.views.MapView)' on a null object reference
at org.osmdroid.views.overlay.DefaultOverlayManager.onTouchEvent(DefaultOverlayManager.java:214)
at org.osmdroid.views.MapView.dispatchTouchEvent(MapView.java:1050)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:552)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1959)
at android.app.Activity.dispatchTouchEvent(Activity.java:3530)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:69)
at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:505)
at android.view.View.dispatchPointerEvent(View.java:12082)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:5325)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:5109)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4676)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4642)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4769)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4650)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4826)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4676)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4642)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4650)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:7222)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:7196)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:7157)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:7379)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:193)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:379)
at android.os.Looper.loop(Looper.java:144)
at android.app.ActivityThread.main(ActivityThread.java:7377)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:469)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:963)
2018-10-02 14:11:45.196 19645-19645/com.message_drop.messagedrop D/AndroidRuntime: Shutting down VM
2018-10-02 14:11:45.201 19645-19645/com.message_drop.messagedrop E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.message_drop.messagedrop, PID: 19645
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean org.osmdroid.views.overlay.Overlay.onTouchEvent(android.view.MotionEvent, org.osmdroid.views.MapView)' on a null object reference
at org.osmdroid.views.overlay.DefaultOverlayManager.onTouchEvent(DefaultOverlayManager.java:214)
at org.osmdroid.views.MapView.dispatchTouchEvent(MapView.java:1050)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:552)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1959)
at android.app.Activity.dispatchTouchEvent(Activity.java:3530)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:69)
at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:505)
at android.view.View.dispatchPointerEvent(View.java:12082)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:5325)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:5109)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4676)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4642)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4769)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4650)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4826)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4676)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4642)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4650)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:7222)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:7196)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:7157)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:7379)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:193)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:379)
at android.os.Looper.loop(Looper.java:144)
at android.app.ActivityThread.main(ActivityThread.java:7377)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:469)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:963)
我不知道如何处理这个错误，希望有人能帮助我。我已经在互联网上寻找解决方案，但没有找到任何解决方案。
如果您需要更多代码，请告诉我。
这是我的 MainActivity.java:
public class MainActivity extends AppCompatActivity implements LocationListener, View.OnClickListener {
MapView mapView;
MyLocationNewOverlay myLocationOverlay;
private static final String TAG = "MainActivity";
String content = "a";
String author = "b";
Double latitude = 53.2;
Double longitude = 11.5;
private ItemizedIconOverlay<OverlayItem> messagesOverlay;
private List<OverlayItem> items = new ArrayList<>();
private long totalNumberChilds;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//set up the mapView and show the MyLocationOverlay
mapView = findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
mapView.setMultiTouchControls(true);
mapView.getController().setZoom(5);
myLocationOverlay = new MyLocationNewOverlay(new GpsMyLocationProvider(getApplicationContext()), mapView);
myLocationOverlay.enableMyLocation();
mapView.getOverlays().add(messagesOverlay);
mapView.getOverlays().add(myLocationOverlay);
GeoPoint point = this.myLocationOverlay.getMyLocation();
if(point==null){
return;
} else {
mapView.getController().animateTo(point);
}
//initialize the Overlay for the Messages
messagesOverlay = new ItemizedIconOverlay<OverlayItem>(items, getResources().getDrawable(R.drawable.briefumschlag), null, this);
//messagesOverlay.addItem(new OverlayItem(author, "", new GeoPoint(latitude, longitude)));
//declare the database variables in onCreate
//NOTE: Unless you are signed in, this will not be useable.
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("message");
// Read from the database
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// This method is called once with the initial value and again
// whenever data at this location is updated.
messagesOverlay.removeAllItems();
Toast.makeText(MainActivity.this, "yesss", Toast.LENGTH_LONG).show();
for (DataSnapshot ds : dataSnapshot.getChildren()) {
//Message message = new Message();
//String author1 = ds.child("messageAuthor").getValue(String.class);
/*String content1 = ds.child("messageContent").getValue(String.class);
Double latitude1 = ds.child("messageLatitude").getValue(Double.class);
Double longitude1 = ds.child("messageLongitude").getValue(Double.class);
messagesOverlay.addItem(new OverlayItem("by" + author1, "", new GeoPoint(latitude1, longitude1)));*/
}
}
@Override
public void onCancelled(DatabaseError error) {
// Failed to read value
}
});
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.testButton) {
addMessage();
}
}
public void addMessage() {
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("message");
String id = myRef.push().getKey();
Message message = new Message(author, content, latitude, longitude);
myRef.child(id).setValue(message);
Toast.makeText(this, "Message added", Toast.LENGTH_LONG).show();
}
@Override
public void onLocationChanged(Location location) {
GeoPoint point = new GeoPoint(location);
if(point==null){
return;
} else {
mapView.getController().animateTo(point);
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
我的LoginActivity.java:
public class LoginActivity extends AppCompatActivity implements View.OnClickListener {
private FirebaseAuth mAuth;
FirebaseAuth.AuthStateListener mAuthListener;
private EditText tfEmail, tfPassword;
private static final String TAG = "LoginActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
tfEmail = findViewById(R.id.tfEmail);
tfPassword = findViewById(R.id.tfPassword);
mAuth = FirebaseAuth.getInstance();
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user != null) {
//User is signed in
Log.d(TAG, "onAuthStateChanged:signed_in" + user.getUid());
Toast.makeText(LoginActivity.this, "Successfully signed in with:" + user.getEmail(),
Toast.LENGTH_SHORT).show();
} else {
//User is signed out
Log.d(TAG, "onAuthStateChanged:signed_out");
Toast.makeText(LoginActivity.this, "Successfully signed out.", Toast.LENGTH_SHORT).show();
}
}
};
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.btnSignIn) {
String email = tfEmail.getText().toString();
String password = tfPassword.getText().toString();
if (!email.equals("") && !password.equals("")) {
mAuth.signInWithEmailAndPassword(email, password);
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
} else {
Toast.makeText(this, "Please fill in all fields!", Toast.LENGTH_SHORT).show();
}
} else if (v.getId() == R.id.btnSignOut) {
mAuth.signOut();
Toast.makeText(this, "Signing Out...", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onStart() {
super.onStart();
// Check if user is signed in (non-null) and update UI accordingly.
mAuth.addAuthStateListener(mAuthListener);
}
@Override
protected void onStop() {
super.onStop();
if (mAuthListener != null) {
mAuth.removeAuthStateListener(mAuthListener);
}
}
}
我的Message.java:
public class Message {
String messageAuthor;
String messageContent;
Double messageLatitude;
Double messageLongitude;
public Message() {
}
public Message(String messageAuthor, String messageContent, Double messageLatitude, Double messageLongitude) {
this.messageAuthor = messageAuthor;
this.messageContent = messageContent;
this.messageLatitude = messageLatitude;
this.messageLongitude = messageLongitude;
}
public String getMessageAuthor() {
return messageAuthor;
}
public String getMessageContent() {
return messageContent;
}
public Double getMessageLatitude() {
return messageLatitude;
}
public Double getMessageLongitude() {
return messageLongitude;
}
public void setMessageAuthor(String messageAuthor) {
this.messageAuthor = messageAuthor;
}
public void setMessageContent(String messageContent) {
this.messageContent = messageContent;
}
public void setMessageLatitude(Double messageLatitude) {
this.messageLatitude = messageLatitude;
}
public void setMessageLongitude(Double messageLongitude) {
this.messageLongitude = messageLongitude;
}
}
我的activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<org.osmdroid.views.MapView
android:id="@+id/mapview"
android:layout_width="match_parent"
android:layout_height="match_parent">
</org.osmdroid.views.MapView>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="onClick"
android:id="@+id/testButton"
android:text="add"
/>
</FrameLayout>
和我的 activity_login.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<EditText
android:id="@+id/tfEmail"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textEmailAddress"
android:hint="Email"/>
<EditText
android:id="@+id/tfPassword"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPassword"
android:hint="Password"/>
<Button
android:id="@+id/btnSignIn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="Sign In"
android:onClick="onClick"/>
<Button
android:id="@+id/btnSignOut"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="Sign Out"
android:onClick="onClick"/>
</LinearLayout>
我应该提到的一件事是，在我添加 LoginActivity 之前 class 地图工作得很好。
仔细检查你的 onCreate 方法：
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//set up the mapView and show the MyLocationOverlay
mapView = findViewById(R.id.mapview);
//... shortened ...
mapView.getOverlays().add(messagesOverlay); // <== here you are adding null, the messagesOevrlay variable is not yet initialized
mapView.getOverlays().add(myLocationOverlay);
//..shortened...
// here you are creating the instance
messagesOverlay = new ItemizedIconOverlay<OverlayItem>(items, getResources().getDrawable(R.drawable.briefumschlag), null, this);
您应该在调用 getOverlays().add() 之前移动创建实例的行，或者将 getOverlays().add(messagesOverlay) 向下移动。
我的应用程序有问题，其中包括 osmdroid。每次我尝试 运行 设备上的应用程序并触摸地图时，应用程序都会崩溃，并且出现此错误：
2018-10-02 14:11:45.191 19645-19645/com.message_drop.messagedrop E/InputEventReceiver: Exception dispatching input event.
2018-10-02 14:11:45.191 19645-19645/com.message_drop.messagedrop E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback
2018-10-02 14:11:45.196 19645-19645/com.message_drop.messagedrop E/MessageQueue-JNI: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean org.osmdroid.views.overlay.Overlay.onTouchEvent(android.view.MotionEvent, org.osmdroid.views.MapView)' on a null object reference
at org.osmdroid.views.overlay.DefaultOverlayManager.onTouchEvent(DefaultOverlayManager.java:214)
at org.osmdroid.views.MapView.dispatchTouchEvent(MapView.java:1050)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:552)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1959)
at android.app.Activity.dispatchTouchEvent(Activity.java:3530)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:69)
at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:505)
at android.view.View.dispatchPointerEvent(View.java:12082)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:5325)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:5109)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4676)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4642)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4769)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4650)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4826)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4676)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4642)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4650)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:7222)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:7196)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:7157)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:7379)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:193)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:379)
at android.os.Looper.loop(Looper.java:144)
at android.app.ActivityThread.main(ActivityThread.java:7377)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:469)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:963)
2018-10-02 14:11:45.196 19645-19645/com.message_drop.messagedrop D/AndroidRuntime: Shutting down VM
2018-10-02 14:11:45.201 19645-19645/com.message_drop.messagedrop E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.message_drop.messagedrop, PID: 19645
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean org.osmdroid.views.overlay.Overlay.onTouchEvent(android.view.MotionEvent, org.osmdroid.views.MapView)' on a null object reference
at org.osmdroid.views.overlay.DefaultOverlayManager.onTouchEvent(DefaultOverlayManager.java:214)
at org.osmdroid.views.MapView.dispatchTouchEvent(MapView.java:1050)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2981)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2611)
at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:552)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1959)
at android.app.Activity.dispatchTouchEvent(Activity.java:3530)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:69)
at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:505)
at android.view.View.dispatchPointerEvent(View.java:12082)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:5325)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:5109)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4676)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4642)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4769)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4650)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4826)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4676)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4642)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4650)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4623)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:7222)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:7196)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:7157)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:7379)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:193)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:379)
at android.os.Looper.loop(Looper.java:144)
at android.app.ActivityThread.main(ActivityThread.java:7377)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:469)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:963)
我不知道如何处理这个错误，希望有人能帮助我。我已经在互联网上寻找解决方案，但没有找到任何解决方案。 如果您需要更多代码，请告诉我。
这是我的 MainActivity.java:
public class MainActivity extends AppCompatActivity implements LocationListener, View.OnClickListener {
MapView mapView;
MyLocationNewOverlay myLocationOverlay;
private static final String TAG = "MainActivity";
String content = "a";
String author = "b";
Double latitude = 53.2;
Double longitude = 11.5;
private ItemizedIconOverlay<OverlayItem> messagesOverlay;
private List<OverlayItem> items = new ArrayList<>();
private long totalNumberChilds;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//set up the mapView and show the MyLocationOverlay
mapView = findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
mapView.setMultiTouchControls(true);
mapView.getController().setZoom(5);
myLocationOverlay = new MyLocationNewOverlay(new GpsMyLocationProvider(getApplicationContext()), mapView);
myLocationOverlay.enableMyLocation();
mapView.getOverlays().add(messagesOverlay);
mapView.getOverlays().add(myLocationOverlay);
GeoPoint point = this.myLocationOverlay.getMyLocation();
if(point==null){
return;
} else {
mapView.getController().animateTo(point);
}
//initialize the Overlay for the Messages
messagesOverlay = new ItemizedIconOverlay<OverlayItem>(items, getResources().getDrawable(R.drawable.briefumschlag), null, this);
//messagesOverlay.addItem(new OverlayItem(author, "", new GeoPoint(latitude, longitude)));
//declare the database variables in onCreate
//NOTE: Unless you are signed in, this will not be useable.
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("message");
// Read from the database
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// This method is called once with the initial value and again
// whenever data at this location is updated.
messagesOverlay.removeAllItems();
Toast.makeText(MainActivity.this, "yesss", Toast.LENGTH_LONG).show();
for (DataSnapshot ds : dataSnapshot.getChildren()) {
//Message message = new Message();
//String author1 = ds.child("messageAuthor").getValue(String.class);
/*String content1 = ds.child("messageContent").getValue(String.class);
Double latitude1 = ds.child("messageLatitude").getValue(Double.class);
Double longitude1 = ds.child("messageLongitude").getValue(Double.class);
messagesOverlay.addItem(new OverlayItem("by" + author1, "", new GeoPoint(latitude1, longitude1)));*/
}
}
@Override
public void onCancelled(DatabaseError error) {
// Failed to read value
}
});
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.testButton) {
addMessage();
}
}
public void addMessage() {
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("message");
String id = myRef.push().getKey();
Message message = new Message(author, content, latitude, longitude);
myRef.child(id).setValue(message);
Toast.makeText(this, "Message added", Toast.LENGTH_LONG).show();
}
@Override
public void onLocationChanged(Location location) {
GeoPoint point = new GeoPoint(location);
if(point==null){
return;
} else {
mapView.getController().animateTo(point);
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
我的LoginActivity.java:
public class LoginActivity extends AppCompatActivity implements View.OnClickListener {
private FirebaseAuth mAuth;
FirebaseAuth.AuthStateListener mAuthListener;
private EditText tfEmail, tfPassword;
private static final String TAG = "LoginActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
tfEmail = findViewById(R.id.tfEmail);
tfPassword = findViewById(R.id.tfPassword);
mAuth = FirebaseAuth.getInstance();
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user != null) {
//User is signed in
Log.d(TAG, "onAuthStateChanged:signed_in" + user.getUid());
Toast.makeText(LoginActivity.this, "Successfully signed in with:" + user.getEmail(),
Toast.LENGTH_SHORT).show();
} else {
//User is signed out
Log.d(TAG, "onAuthStateChanged:signed_out");
Toast.makeText(LoginActivity.this, "Successfully signed out.", Toast.LENGTH_SHORT).show();
}
}
};
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.btnSignIn) {
String email = tfEmail.getText().toString();
String password = tfPassword.getText().toString();
if (!email.equals("") && !password.equals("")) {
mAuth.signInWithEmailAndPassword(email, password);
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
} else {
Toast.makeText(this, "Please fill in all fields!", Toast.LENGTH_SHORT).show();
}
} else if (v.getId() == R.id.btnSignOut) {
mAuth.signOut();
Toast.makeText(this, "Signing Out...", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onStart() {
super.onStart();
// Check if user is signed in (non-null) and update UI accordingly.
mAuth.addAuthStateListener(mAuthListener);
}
@Override
protected void onStop() {
super.onStop();
if (mAuthListener != null) {
mAuth.removeAuthStateListener(mAuthListener);
}
}
}
我的Message.java:
public class Message {
String messageAuthor;
String messageContent;
Double messageLatitude;
Double messageLongitude;
public Message() {
}
public Message(String messageAuthor, String messageContent, Double messageLatitude, Double messageLongitude) {
this.messageAuthor = messageAuthor;
this.messageContent = messageContent;
this.messageLatitude = messageLatitude;
this.messageLongitude = messageLongitude;
}
public String getMessageAuthor() {
return messageAuthor;
}
public String getMessageContent() {
return messageContent;
}
public Double getMessageLatitude() {
return messageLatitude;
}
public Double getMessageLongitude() {
return messageLongitude;
}
public void setMessageAuthor(String messageAuthor) {
this.messageAuthor = messageAuthor;
}
public void setMessageContent(String messageContent) {
this.messageContent = messageContent;
}
public void setMessageLatitude(Double messageLatitude) {
this.messageLatitude = messageLatitude;
}
public void setMessageLongitude(Double messageLongitude) {
this.messageLongitude = messageLongitude;
}
}
我的activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<org.osmdroid.views.MapView
android:id="@+id/mapview"
android:layout_width="match_parent"
android:layout_height="match_parent">
</org.osmdroid.views.MapView>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="onClick"
android:id="@+id/testButton"
android:text="add"
/>
</FrameLayout>
和我的 activity_login.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<EditText
android:id="@+id/tfEmail"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textEmailAddress"
android:hint="Email"/>
<EditText
android:id="@+id/tfPassword"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPassword"
android:hint="Password"/>
<Button
android:id="@+id/btnSignIn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="Sign In"
android:onClick="onClick"/>
<Button
android:id="@+id/btnSignOut"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="Sign Out"
android:onClick="onClick"/>
</LinearLayout>
我应该提到的一件事是，在我添加 LoginActivity 之前 class 地图工作得很好。
仔细检查你的 onCreate 方法：
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//set up the mapView and show the MyLocationOverlay
mapView = findViewById(R.id.mapview);
//... shortened ...
mapView.getOverlays().add(messagesOverlay); // <== here you are adding null, the messagesOevrlay variable is not yet initialized
mapView.getOverlays().add(myLocationOverlay);
//..shortened...
// here you are creating the instance
messagesOverlay = new ItemizedIconOverlay<OverlayItem>(items, getResources().getDrawable(R.drawable.briefumschlag), null, this);
您应该在调用 getOverlays().add() 之前移动创建实例的行，或者将 getOverlays().add(messagesOverlay) 向下移动。