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28
4
我得到了
Attempt to invoke virtual method 'void android.support.v7.app.MediaRouteActionProvider.setRouteSelector(android.support.v7.media.MediaRouteSelector)' on a null object reference
当我想为我的应用程序添加强制转换支持时，我已经在一个单独的项目中创建了所有内容，现在我只想将所有内容转移到我的应用程序中，但我遇到了这个异常。我看不出我在哪里犯了错误.这是我的代码:
......
private MediaRouter mMediaRouter;
private MediaRouteSelector mMediaRouteSelector;
private MediaRouter.Callback mMediaRouterCallback;
private CastDevice mSelectedDevice;
private GoogleApiClient mApiClient;
private Cast.Listener mCastListener;
private GoogleApiClient.ConnectionCallbacks mConnectionCallbacks;
private ConnectionFailedListener mConnectionFailedListener;
private HelloWorldChannel mHelloWorldChannel;
private boolean mApplicationStarted;
private boolean mWaitingForReconnect;
private String mSessionId;
@Override
protected void onCreate(Bundle savedInstanceState) {
//for transaltion
SharedPreferences LengPref = getSharedPreferences("language",
MODE_PRIVATE);
String langStr = LengPref.getString("lang", "");
String languageToLoad = langStr;
Locale locale = new Locale(languageToLoad);
Locale.setDefault(locale);
Configuration config = new Configuration();
config.locale = locale;
getBaseContext().getResources().updateConfiguration(config, null);
// for transaltion
super.onCreate(savedInstanceState);
// Configure Cast device discovery
mMediaRouter = MediaRouter.getInstance(getApplicationContext());
mMediaRouteSelector = new MediaRouteSelector.Builder()
.addControlCategory(CastMediaControlIntent.categoryForCast(getResources()
.getString(R.string.app_id))).build();
mMediaRouterCallback = new MyMediaRouterCallback();
.....
}
private class MyMediaRouterCallback extends MediaRouter.Callback {
@Override
public void onRouteSelected(MediaRouter router, MediaRouter.RouteInfo info) {
//Log.d(TAG, "onRouteSelected");
// Handle the user route selection.
mSelectedDevice = CastDevice.getFromBundle(info.getExtras());
launchReceiver();
}
@Override
public void onRouteUnselected(MediaRouter router, MediaRouter.RouteInfo info) {
//Log.d(TAG, "onRouteUnselected: info=" + info);
teardown(false);
mSelectedDevice = null;
}
}
.......
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu items for use in the action bar
MenuInflater inflater = getMenuInflater();
//getMenuInflater().inflate(R.menu.main, menu);
if (workoutTypeFinal == 0) {
inflater.inflate(R.menu.workout_menu, menu);
} else if (workoutTypeFinal == 2 || workoutTypeFinal == 3) {
inflater.inflate(R.menu.workout_menu, menu);
} else {
//ovo je ako je next next tip
inflater.inflate(R.menu.workout_menu_2, menu);
}
MenuItem mediaRouteMenuItem = menu.findItem(R.id.media_route_menu_item);
MediaRouteActionProvider mediaRouteActionProvider
= (MediaRouteActionProvider) MenuItemCompat
.getActionProvider(mediaRouteMenuItem);
// Set the MediaRouteActionProvider selector for device discovery.
mediaRouteActionProvider.setRouteSelector(mMediaRouteSelector);
mOptionsMenu = menu;
return super.onCreateOptionsMenu(menu);
}
.....
@Override
protected void onStop() {
mMediaRouter.removeCallback(mMediaRouterCallback);
super.onStop();
if (hasTimer == true) {
timer5.cancel();
timer2.cancel();
}
if (workoutTypeFinal == 0) {
//inflater.inflate(R.menu.workout_menu, menu);
if (isTimer1 == true) {
timer1.cancel();
//timer5.cancel();
//mp.stop();
} else if (isTimer2 == true) {
timer2.cancel();
timer5.cancel();
if (isMusic == true) {
mp.stop();
} else {
}
} else if (isTimer3 == true) {
timer3.cancel();
timer5.cancel();
mp.stop();
} else if (isTimer4 == true) {
timer4.cancel();
timer5.cancel();
mp.stop();
}
} else if (workoutTypeFinal == 2) {
//inflater.inflate(R.menu.workout_menu, menu);
} else {
//ovo je ako je next next tip
//inflater.inflate(R.menu.workout_menu_2, menu);
}
}
@Override
protected void onPause() {
super.onPause();
//pausedVoid=false;
if (workoutTypeFinal == 0) {
if (pausedVoid == true) {
} else {
pauseTime();
}
} else if (workoutTypeFinal == 2) {
if (pausedVoid == true) {
} else {
pauseTime();
}
//asd
} else {
//ovo je ako je next next tip
}
}
@Override
protected void onDestroy() {
teardown(true);
super.onDestroy();
if (hasTimer == true) {
timer5.cancel();
timer2.cancel();
}
if (workoutTypeFinal == 0) {
//inflater.inflate(R.menu.workout_menu, menu);
if (isTimer1 == true) {
timer1.cancel();
//timer5.cancel();
//mp.stop();
} else if (isTimer2 == true) {
timer2.cancel();
timer5.cancel();
if (isMusic == true) {
mp.stop();
} else {
}
} else if (isTimer3 == true) {
timer3.cancel();
timer5.cancel();
mp.stop();
} else if (isTimer4 == true) {
timer4.cancel();
timer5.cancel();
mp.stop();
}
} else if (workoutTypeFinal == 2) {
//inflater.inflate(R.menu.workout_menu, menu);
if (isTimer1 == true) {
timer1.cancel();
//timer5.cancel();
//mp.stop();
} else if (isTimer2 == true) {
timer2.cancel();
timer5.cancel();
if (isMusic == true) {
mp.stop();
} else {
}
} else if (isTimer3 == true) {
timer3.cancel();
timer5.cancel();
mp.stop();
} else if (isTimer4 == true) {
timer4.cancel();
timer5.cancel();
mp.stop();
}
} else {
//ovo je ako je next next tip
}
}
@Override
protected void onResume() {
super.onResume();
}
........
@Override
protected void onStart() {
super.onStart();
// Start media router discovery
mMediaRouter.addCallback(mMediaRouteSelector, mMediaRouterCallback,
MediaRouter.CALLBACK_FLAG_REQUEST_DISCOVERY);
}
//Chromecast
/**
* Start the receiver app
*/
private void launchReceiver() {
try {
mCastListener = new Cast.Listener() {
@Override
public void onApplicationDisconnected(int errorCode) {
Log.d(TAG, "application has stopped");
teardown(true);
}
};
// Connect to Google Play services
mConnectionCallbacks = new ConnectionCallbacks();
mConnectionFailedListener = new ConnectionFailedListener();
Cast.CastOptions.Builder apiOptionsBuilder = Cast.CastOptions
.builder(mSelectedDevice, mCastListener);
mApiClient = new GoogleApiClient.Builder(this)
.addApi(Cast.API, apiOptionsBuilder.build())
.addConnectionCallbacks(mConnectionCallbacks)
.addOnConnectionFailedListener(mConnectionFailedListener)
.build();
mApiClient.connect();
} catch (Exception e) {
Log.e(TAG, "Failed launchReceiver", e);
}
}
/**
* Google Play services callbacks
*/
private class ConnectionCallbacks implements GoogleApiClient.ConnectionCallbacks {
@Override
public void onConnected(Bundle connectionHint) {
Log.d(TAG, "onConnected");
if (mApiClient == null) {
// We got disconnected while this runnable was pending
// execution.
return;
}
try {
if (mWaitingForReconnect) {
mWaitingForReconnect = false;
// Check if the receiver app is still running
if ((connectionHint != null)
&& connectionHint.getBoolean(Cast.EXTRA_APP_NO_LONGER_RUNNING)) {
Log.d(TAG, "App is no longer running");
teardown(true);
} else {
// Re-create the custom message channel
try {
Cast.CastApi.setMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_round(),
mHelloWorldChannel);
Cast.CastApi.setMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_text(),
mHelloWorldChannel);
Cast.CastApi.setMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_exercise(),
mHelloWorldChannel);
Cast.CastApi.setMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_time(),
mHelloWorldChannel);
} catch (IOException e) {
Log.e(TAG, "Exception while creating channel", e);
}
}
} else {
// Launch the receiver app
Cast.CastApi.launchApplication(mApiClient, getString(R.string.app_id), false)
.setResultCallback(
new ResultCallback<Cast.ApplicationConnectionResult>() {
@Override
public void onResult(
Cast.ApplicationConnectionResult result) {
Status status = result.getStatus();
Log.d(TAG,
"ApplicationConnectionResultCallback.onResult:"
+ status.getStatusCode());
if (status.isSuccess()) {
ApplicationMetadata applicationMetadata = result
.getApplicationMetadata();
mSessionId = result.getSessionId();
String applicationStatus = result
.getApplicationStatus();
boolean wasLaunched = result.getWasLaunched();
Log.d(TAG, "application name: "
+ applicationMetadata.getName()
+ ", status: " + applicationStatus
+ ", sessionId: " + mSessionId
+ ", wasLaunched: " + wasLaunched);
mApplicationStarted = true;
// Create the custom message
// channel
mHelloWorldChannel = new HelloWorldChannel();
try {
Cast.CastApi.setMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_round(),
mHelloWorldChannel);
Cast.CastApi.setMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_text(),
mHelloWorldChannel);
Cast.CastApi.setMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_exercise(),
mHelloWorldChannel);
Cast.CastApi.setMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_time(),
mHelloWorldChannel);
} catch (IOException e) {
Log.e(TAG, "Exception while creating channel",
e);
}
// set the initial instructions
// on the receiver
//Salje Talk to me text
//sendMessage(getString(R.string.instructions),0);
} else {
Log.e(TAG, "application could not launch");
teardown(true);
}
}
});
}
} catch (Exception e) {
Log.e(TAG, "Failed to launch application", e);
}
}
@Override
public void onConnectionSuspended(int cause) {
Log.d(TAG, "onConnectionSuspended");
mWaitingForReconnect = true;
}
}
/**
* Google Play services callbacks
*/
private class ConnectionFailedListener implements
GoogleApiClient.OnConnectionFailedListener {
@Override
public void onConnectionFailed(ConnectionResult result) {
Log.e(TAG, "onConnectionFailed ");
teardown(false);
}
}
/**
* Tear down the connection to the receiver
*/
private void teardown(boolean selectDefaultRoute) {
Log.d(TAG, "teardown");
if (mApiClient != null) {
if (mApplicationStarted) {
if (mApiClient.isConnected() || mApiClient.isConnecting()) {
try {
Cast.CastApi.stopApplication(mApiClient, mSessionId);
if (mHelloWorldChannel != null) {
Cast.CastApi.removeMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_round());
Cast.CastApi.removeMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_text());
Cast.CastApi.removeMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_exercise());
Cast.CastApi.removeMessageReceivedCallbacks(
mApiClient,
mHelloWorldChannel.get_messageBus_current_time());
mHelloWorldChannel = null;
}
} catch (IOException e) {
Log.e(TAG, "Exception while removing channel", e);
}
mApiClient.disconnect();
}
mApplicationStarted = false;
}
mApiClient = null;
}
if (selectDefaultRoute) {
mMediaRouter.selectRoute(mMediaRouter.getDefaultRoute());
}
mSelectedDevice = null;
mWaitingForReconnect = false;
mSessionId = null;
}
/**
* Send a text message to the receiver
*/
private void sendMessage(String message,int case_) {
if (mApiClient != null && mHelloWorldChannel != null) {
try {
//Salje stranici message od text speacha
if(case_ == 0){
Cast.CastApi.sendMessage(mApiClient, mHelloWorldChannel.get_messageBus_round(), message).setResultCallback(
new ResultCallback<Status>() {
@Override
public void onResult(Status result) {
if (!result.isSuccess()) {
Log.e(TAG, "Sending message failed");
}
}
});
}else if(case_ == 1){
Cast.CastApi.sendMessage(mApiClient, mHelloWorldChannel.get_messageBus_current_text(), message).setResultCallback(
new ResultCallback<Status>() {
@Override
public void onResult(Status result) {
if (!result.isSuccess()) {
Log.e(TAG, "Sending message failed");
}
}
});
}else if(case_ == 2){
Cast.CastApi.sendMessage(mApiClient, mHelloWorldChannel.get_messageBus_current_exercise(), message).setResultCallback(
new ResultCallback<Status>() {
@Override
public void onResult(Status result) {
if (!result.isSuccess()) {
Log.e(TAG, "Sending message failed");
}
}
});
}else if(case_ == 3){
Cast.CastApi.sendMessage(mApiClient, mHelloWorldChannel.get_messageBus_current_time(), message).setResultCallback(
new ResultCallback<Status>() {
@Override
public void onResult(Status result) {
if (!result.isSuccess()) {
Log.e(TAG, "Sending message failed");
}
}
});
}
} catch (Exception e) {
Log.e(TAG, "Exception while sending message", e);
}
} else {
//Toast.makeText(MainActivity.this, message, Toast.LENGTH_SHORT).show();
}
}
/**
* Custom message channel
*/
class HelloWorldChannel implements Cast.MessageReceivedCallback {
/**
* @return custom namespace
*/
public String get_messageBus_round(){
return getString(R.string.messageBus_round);
}
public String get_messageBus_current_text(){
return getString(R.string.messageBus_current_text);
}
public String get_messageBus_current_exercise(){
return getString(R.string.messageBus_current_exercise);
}
public String get_messageBus_current_time(){
return getString(R.string.messageBus_current_time);
}
/*
* Receive message from the receiver app
*/
@Override
public void onMessageReceived(CastDevice castDevice, String namespace,
String message) {
Log.d(TAG, "onMessageReceived: " + message);
}
}
}
最佳答案
问题出在菜单上，菜单应该是这样的:
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.casthelloworld.MainActivity" >
<item
android:id="@+id/media_route_menu_item"
android:title="@string/media_route_menu_title"
app:actionProviderClass="android.support.v7.app.MediaRouteActionProvider"
app:showAsAction="always"/>
</menu>
关于java - 尝试调用虚方法 'void android.support.v7.app.MediaRouteActionProvider.setRouteSelector，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37752643/
28
4
0
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