I am facing issue with my code.I am getting RuntimeException.Kindly please do help me with this.
I'm getting the following error log :
06-17 18:11:32.646 13750-13750/? E/Zygote: v2
06-17 18:11:32.646 13750-13750/? E/Zygote: accessInfo : 0
06-17 18:11:33.226 13750-13750/com.example.cocol.timisoara2021 E/MotionRecognitionManager: mSContextService = android.hardware.scontext.ISContextService$Stub$Proxy#f847827
06-17 18:11:33.226 13750-13750/com.example.cocol.timisoara2021 E/MotionRecognitionManager: motionService = com.samsung.android.motion.IMotionRecognitionService$Stub$Proxy#d2d3ad4
06-17 18:11:33.226 13750-13750/com.example.cocol.timisoara2021 E/MotionRecognitionManager: motionService = com.samsung.android.motion.IMotionRecognitionService$Stub$Proxy#d2d3ad4
06-17 18:11:36.566 13750-14348/com.example.cocol.timisoara2021 E/GooglePlayServicesUtil: The Google Play services resources were not found. Check your project configuration to ensure that the resources are included.
06-17 18:11:36.666 13750-13750/com.example.cocol.timisoara2021 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.cocol.timisoara2021, PID: 13750
java.lang.RuntimeException: Unable to resume activity {com.example.cocol.timisoara2021/com.example.cocol.timisoara2021.Main2Activity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.wikitude.common.orientation.internal.a.a()' on a null object reference
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4226)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4328)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3427)
at android.app.ActivityThread.access$1100(ActivityThread.java:229)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1821)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:7407)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.wikitude.common.orientation.internal.a.a()' on a null object reference
at com.wikitude.architect.ArchitectView.onResume(ProGuard:818)
at com.example.cocol.timisoara2021.Main2Activity.onResume(Main2Activity.java:59)
at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1287)
at android.app.Activity.performResume(Activity.java:7015)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4215)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4328)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3427)
at android.app.ActivityThread.access$1100(ActivityThread.java:229)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1821)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:7407)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
And here is the line 53:architectView.onResume();
And the code:
package com.example.cocol.timisoara2021;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import com.wikitude.architect.ArchitectStartupConfiguration;
import com.wikitude.architect.ArchitectView;
public class Main2Activity extends AppCompatActivity {
private ArchitectView architectView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
this.architectView = (ArchitectView) this.findViewById(R.id.architectView);
final ArchitectStartupConfiguration config = new ArchitectStartupConfiguration();
config.setLicenseKey("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");
this.architectView.onCreate(config);
}
protected void OnPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
architectView.onPostCreate();
try {
this.architectView.load("file:///android_asset/POI/index.html");
}catch (Exception e) {
}
}
#Override
protected void onPause() {
super.onPause();
architectView.onPause();
}
#Override
protected void onResume() {
super.onResume();
architectView.onResume();
}
#Override
protected void onDestroy() {
super.onDestroy();
architectView.onDestroy();
}
}
How can I fix this ?
Your onPostCreate method has an uppercase "O". Because of this i assume it is never called which means that the ArchitectView is in an invalid state when you call architectView.onResume.
Try:
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
architectView.onPostCreate();
try {
this.architectView.load("file:///android_asset/POI/index.html");
}catch (Exception e) {
}
}
Related
public abstract class MainActivity extends AppCompatActivity {
Button decrement;
Button increment;
TextView counter_view;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Log.i("tag", "onCreate: Created Successfully");
increment=findViewById(R.id.inc_btn);
decrement=findViewById(R.id.dec_btn);
counter_view=findViewById(R.id.counter);
increment.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String cnt_text=counter_view.getText().toString();
int cnt_no= Integer.parseInt(cnt_text);
cnt_no=cnt_no+1;
counter_view.setText(cnt_no+"");
}
});
decrement.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String cnt_text=counter_view.getText().toString();
int cnt_no=Integer.parseInt(cnt_text);
cnt_no=cnt_no-1;
counter_view.setText(cnt_no+"");
}
});
}
Error:
2021-02-10 00:29:06.870 16714-16714/? E/Zygote: v2
2021-02-10 00:29:06.871 16714-16714/? E/Zygote: accessInfo : 0
2021-02-10 00:29:07.017 16714-16714/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.counter_app, PID: 16714
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.counter_app/com.example.counter_app.MainActivity}: java.lang.InstantiationException: java.lang.Class<com.example.counter_app.MainActivity> cannot be instantiated
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2849)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3045)
at android.app.ActivityThread.-wrap14(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1642)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
Caused by: java.lang.InstantiationException: java.lang.Class<com.example.counter_app.MainActivity> cannot be instantiated
at java.lang.Class.newInstance(Native Method)
at android.app.Instrumentation.newActivity(Instrumentation.java:1086)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2839)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3045)
at android.app.ActivityThread.-wrap14(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1642)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
I suppose this is your first screen/activity/class that is displayed on launch i.e it is your launcher activity. If yes,
the launcher activity cannot be abstract. Because when an app is launched from the home screen on an Android device, the Android OS creates an instance of the activity in the application you have declared to be the launcher activity. And abstract classes can not be instantiated, they can only be sub-classed.
Please remove the word abstract before your class name.
add to your manifest file this line
<activity android:name="your.package.name.MainActivity"/>
Everytime the application gets to my second activity it crashes, giving the error.
My activity:
public class SecondActivity extends AppCompatActivity {
EditText barcodeText = findViewById(R.id.barcodeText);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
IntentFilter filter = new IntentFilter();
filter.addCategory(Intent.CATEGORY_DEFAULT);
filter.addAction(getResources().getString(R.string.activity_intent_filter_action));
registerReceiver(myBroadcastReceiver, filter);
}
private BroadcastReceiver myBroadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
Bundle b = intent.getExtras();
if (action.equals(getResources().getString(R.string.activity_intent_filter_action))) {
try {
displayScanResult(intent);
} catch (Exception e) {
}
}
}
};
private void displayScanResult(Intent initiatingIntent)
{
String decodedSource = initiatingIntent.getStringExtra(getResources().getString(R.string.datawedge_intent_key_source));
String decodedData = initiatingIntent.getStringExtra(getResources().getString(R.string.datawedge_intent_key_data));
String decodedLabelType = initiatingIntent.getStringExtra(getResources().getString(R.string.datawedge_intent_key_label_type));
barcodeText.setText(decodedData);
}
}
Logcat:
07-01 12:37:03.373 349-349/com.example.provatimer E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.provatimer, PID: 349
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.provatimer/com.example.provatimer.SecondActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2236)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5256)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
at android.content.ContextWrapper.getApplicationInfo(ContextWrapper.java:149)
at android.view.ContextThemeWrapper.getTheme(ContextThemeWrapper.java:99)
at android.content.Context.obtainStyledAttributes(Context.java:438)
at androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor(AppCompatDelegateImpl.java:692)
at androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor(AppCompatDelegateImpl.java:659)
at androidx.appcompat.app.AppCompatDelegateImpl.findViewById(AppCompatDelegateImpl.java:479)
at androidx.appcompat.app.AppCompatActivity.findViewById(AppCompatActivity.java:214)
at com.example.provatimer.SecondActivity.<init>(SecondActivity.java:14)
at java.lang.reflect.Constructor.newInstance(Native Method)
at java.lang.Class.newInstance(Class.java:1606)
at android.app.Instrumentation.newActivity(Instrumentation.java:1066)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2226)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5256)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)
I think it may have something to do with the context in the BroadcastReceiver, but I tried to declare it in the onCreate method but nothing changed.
Maybe I don't initialize correctly the intent in which the data should be stored, if so, how can I do it correctly?
All the Strings should be correct int the string.xml file, if the error may come from that I'll write them.
I think the error is happening here:
EditText barcodeText = findViewById(R.id.barcodeText);
You are invoking findViewById() directly in the class member declaration.
You have invoke findViewById() after setContentView()
EditText barcodeText;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
barcodeText = findViewById(R.id.barcodeText);
}
I want to change from main activity to login activity through button log in. i followed all the steps but it still doesn't work when i test it on my device.
this is main.java:
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
View v = findViewById(R.id.buttonlog);
v.setOnClickListener((View.OnClickListener) this);
}
#Override
public void onClick(View v) {
if(v.getId()==R.id.buttonlog)
{
Intent intent = new Intent(this,LoginActivity.class);
this.startActivity(intent);
}
}}
Login activity is:
public class LoginActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
}
}
The Logcat:
12-06 19:57:03.960 6374-6374/com.example.ancaalexandra.proiectandroidd D/ViewRootImpl#c94e23f[MainActivity]: ViewPostImeInputStage processPointer 0
12-06 19:57:03.961 6374-6374/com.example.ancaalexandra.proiectandroidd E/BoostFramework: BoostFramework() : Exception_1 = java.lang.ClassNotFoundException: Didn't find class "com.qualcomm.qti.Performance" on path: DexPathList[[],nativeLibraryDirectories=[/system/lib64, /vendor/lib64]]
12-06 19:57:03.961 6374-6374/com.example.ancaalexandra.proiectandroidd V/BoostFramework: BoostFramework() : mPerf = null
12-06 19:57:04.046 6374-6374/com.example.ancaalexandra.proiectandroidd D/ViewRootImpl#c94e23f[MainActivity]: ViewPostImeInputStage processPointer 1
12-06 19:57:04.435 6374-6374/com.example.ancaalexandra.proiectandroidd D/ViewRootImpl#c94e23f[MainActivity]: ViewPostImeInputStage processPointer 0
12-06 19:57:04.522 6374-6374/com.example.ancaalexandra.proiectandroidd D/ViewRootImpl#c94e23f[MainActivity]: ViewPostImeInputStage processPointer 1
12-06 19:57:04.791 6374-6374/com.example.ancaalexandra.proiectandroidd D/ViewRootImpl#c94e23f[MainActivity]: MSG_WINDOW_FOCUS_CHANGED 0
12-06 19:57:04.837 6374-6374/com.example.ancaalexandra.proiectandroidd D/AndroidRuntime: Shutting down VM
12-06 19:57:04.838 6374-6374/com.example.ancaalexandra.proiectandroidd E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.ancaalexandra.proiectandroidd, PID: 6374
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ancaalexandra.proiectandroidd/com.example.ancaalexandra.proiectandroidd.LoginActivity}: java.lang.ClassCastException: com.example.ancaalexandra.proiectandroidd.LoginActivity cannot be cast to android.view.View$OnClickListener
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2984)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3045)
at android.app.ActivityThread.-wrap14(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1642)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
Caused by: java.lang.ClassCastException: com.example.ancaalexandra.proiectandroidd.LoginActivity cannot be cast to android.view.View$OnClickListener
at com.example.ancaalexandra.proiectandroidd.LoginActivity.onCreate(LoginActivity.java:19)
at android.app.Activity.performCreate(Activity.java:6956)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1126)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2927)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3045)
at android.app.ActivityThread.-wrap14(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1642)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
I declared both activities in the manifest file. What i did wrong? thank you!
Your way of handling findViewById() and setting onClick listener is quite unusual.
Change this code :
View v = findViewById(R.id.buttonlog);
v.setOnClickListener((View.OnClickListener) this);
to this code :
Button loginButton = (Button)findViewById(R.id.buttonlog);
loginButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(MainActivity.this,LoginActivity.class);
startActivity(intent);
}
});
And it should work just fine.
Your error is on this line:
v.setOnClickListener((View.OnClickListener) this);
which is explained in your stacktrace:
LoginActivity cannot be cast to android.view.View$OnClickListener
You are trying to cast your Activity LoginActivityto an OnClickListener, which won't work.
If your Activity implements an OnClickListener you just need to pass this :
class LoginActivity extends Activity implements OnClickListener {
protected void onCreate(Bundle savedValues) {
...
v.setOnClickListener(this)
}
}
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 5 years ago.
On every app start there is a error message on my phone: "The Application was ended, sorry". What can I do now? I already searched the web and I tried to solve it, but I didn't found a answer.
This is my logcat output:
FATAL EXCEPTION: main
Process: mycompany.kopfrechnenti1907_1839, PID: 524
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{mycompany.kopfrechnenti1907_1839/mycompany.kopfrechnenti1907_1839.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2363)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
at android.app.ActivityThread.access$900(ActivityThread.java:158)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5521)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:804)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:666)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
at android.support.v7.app.AppCompatDelegateImplBase.<init>(AppCompatDelegateImplBase.java:120)
at android.support.v7.app.AppCompatDelegateImplV9.<init>(AppCompatDelegateImplV9.java:155)
at android.support.v7.app.AppCompatDelegateImplV11.<init>(AppCompatDelegateImplV11.java:31)
at android.support.v7.app.AppCompatDelegateImplV14.<init>(AppCompatDelegateImplV14.java:55)
at android.support.v7.app.AppCompatDelegateImplV23.<init>(AppCompatDelegateImplV23.java:33)
at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:203)
at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:185)
at android.support.v7.app.AppCompatActivity.getDelegate(AppCompatActivity.java:519)
at android.support.v7.app.AppCompatActivity.findViewById(AppCompatActivity.java:190)
at mycompany.kopfrechnenti1907_1839.MainActivity.<init>(MainActivity.java:10)
at java.lang.Class.newInstance(Native Method)
at android.app.Instrumentation.newActivity(Instrumentation.java:1069)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2353)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
at android.app.ActivityThread.access$900(ActivityThread.java:158)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5521)
at java.lang.reflect.Method.invoke(Native Method)
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.RatingBar;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
Button btnplus = (Button)findViewById(R.id.btnplus);
RatingBar ratingbar = (RatingBar)findViewById(R.id.ratingBar);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void plusonclick()
{
if (ratingbar.getRating() == 1)
{
setContentView(R.layout.activity_plusrechnenlvl1);
}
}
}
My English skills are not the best, but I hope you can understand me :)
Thank you very much!
Jul
you have to write following in onCreate after
setContentView()
Button btnplus = (Button)findViewById(R.id.btnplus);
RatingBar ratingbar = (RatingBar)findViewById(R.id.ratingBar);
like below.
public class MainActivity extends AppCompatActivity {
Button btnplus;
RatingBar ratingbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnplus = (Button)findViewById(R.id.btnplus);
ratingbar = (RatingBar)findViewById(R.id.ratingBar);
}
public void plusonclick()
{
if (ratingbar.getRating() == 1)
{
setContentView(R.layout.activity_plusrechnenlvl1);
}
}
}
Please check whats the problem with my code here :
Main Activity :
I'm using Android Studio. Import statements are managed for me. It won't be necessary to write them here
public class MainActivity extends Activity implements View.OnClickListener {
SharedPreferences prefs;
String dataName = "MyData";
String intName = "MyString";
int defaultInt = 0;
public static int highScore;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button buttonPlay = (Button) findViewById(R.id.btnPlay);
TextView textHighScore = (TextView) findViewById(R.id.textHighScore);
buttonPlay.setOnClickListener(this);
prefs = getSharedPreferences(dataName, MODE_PRIVATE);
highScore = prefs.getInt(intName, defaultInt);
textHighScore.setText("High Score: " + highScore);
}
#Override
public void onClick(View view) {
Intent intent;
intent = new Intent(this, GameActivity.class);
startActivity(intent);
}
}
When I run this application Main Activity is loaded but when I hit play button application closes. I have checked the play button's ID is O.K. I had the same problem in GameActivity but at last I figured out that the problem was with the ID but this time I think problem is with the this I used in Intent();. Activity fails to load.
Exception :
06-24 01:34:05.196 12826-12826/com.cruzerblade.memorygame E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.cruzerblade.memorygame, PID: 12826
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.cruzerblade.memorygame/com.cruzerblade.memorygame.GameActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2327)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
at android.content.ContextWrapper.getResources(ContextWrapper.java:87)
at android.view.ContextThemeWrapper.getResources(ContextThemeWrapper.java:81)
at android.view.animation.AnimationUtils.loadAnimation(AnimationUtils.java:75)
at com.cruzerblade.memorygame.GameActivity.<init>(GameActivity.java:55)
at java.lang.Class.newInstance(Native Method)
at android.app.Instrumentation.newActivity(Instrumentation.java:1067)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Please help me out! It took me too much time still I couldn't figure out the problem.
Quoting from your logcat:
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method
'android.content.res.Resources android.content.Context.getResources()'
on a null object reference
at android.content.ContextWrapper.getResources(ContextWrapper.java:87)
at android.view.ContextThemeWrapper.getResources(ContextThemeWrapper.java:81)
at android.view.animation.AnimationUtils.loadAnimation(AnimationUtils.java:75)
at com.cruzerblade.memorygame.GameActivity.<init>(GameActivity.java:55)
This last line is the only line in the trace that is your code:
Look on line 55 of GameActivity.java. It is calling loadAnimation. There is something wrong with the animation it is trying to load (probably a missing resource ID, but it could also be a null or invalid context argument for loadAnimation.)