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Crash after splashscreen

i'm new at android studio and i'm developing my first app.
Everything worked fine until i implemented a splashscreen. Indeed, when i run the app, the splashcreen works, but then, it crashes.
The thing is that the splashscreen wasn't the first activity i've created (the main). I've created my app and when i finished it, i added a splashscreen.
Actually when i disable the splashscreen (the activity) and start directly with the previous "activity that appears on launch" (that is the "Menu"), it works fine.
And one weird thing: with the splashscreen enabled, it crashes only with certain devices. It runs perfectly with my Xiaomi Redmi Note 5 and a Galaxy S4 (or the nexus 5X emulator) but not with a Galaxy S3 and S6 .
I tried to replace the timer by a simple setonclicklistener button. But same, when it has to load the Menu, it crashes.
I haven't find similar problems on the forums so here i am !
The manifest:
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="false"
android:theme="#style/AppTheme">
<activity android:name=".Menu"/>
<activity android:name=".restaurant" />
<activity android:name=".courses" />
<activity android:name=".toilettes" />
<activity android:name=".distributeur" />
<activity android:name=".essence" />
<activity android:name=".hopital" />
<activity android:name=".Splashscreen">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MainActivity"/>
<activity
android:name="com.google.android.gms.ads.AdActivity"
android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"
android:theme="#android:style/Theme.Translucent" />
</application>
Here is the Splashscreen -java
package fr.libertyg.messervices;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.os.Handler;
import android.provider.ContactsContract;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.Timer;
public class Splashscreen extends AppCompatActivity {
private ImageView daccord;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
setContentView(R.layout.activity_splashscreen);
final TextView random = (TextView) findViewById(R.id.random);
final String[] mesphrases = {"S1", "S2",
"S3", "S4", "S5","S6"};
int rando = (int) (Math.random() * 6);
random.setText(mesphrases[rando]);
this.daccord = findViewById(R.id.daccord);
daccord.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent otheractivity = new Intent(Splashscreen.this, Menu.class);
startActivity(otheractivity);
finish();
}
});
}
The Splashscreen xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Splashscreen"
android:weightSum="10"
android:orientation="vertical"
android:background="#drawable/splashscreenfond">
<RelativeLayout
android:layout_weight="1.5"
android:layout_width="match_parent"
android:layout_height="0dp">
<TextView
android:id="#+id/spashscreenbienvenue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="#string/splashscreenbienvenue"
android:textSize="40sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="5">
<ImageView
android:id="#+id/logo"
android:layout_width="249dp"
android:layout_height="217dp"
android:layout_centerInParent="true"
android:src="#drawable/icon" />
<TextView
android:id="#+id/nom"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="#string/app_name"
android:textSize="30sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1.5">
<TextView
android:id="#+id/bonasavoir"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:text="#string/bonasavoir"
android:textSize="17sp" />
<TextView
android:id="#+id/donnees"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/random"
android:layout_centerHorizontal="true"
android:text="#string/activezgps"
android:textSize="14sp" />
<TextView
android:id="#+id/random"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="13dp"
android:text="Un être humain a besoin d'environ 2000 kcal/jour"
android:textSize="14sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="2">
<TextView
android:id="#+id/version"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="#string/version" />
<ImageView
android:id="#+id/daccord"
android:layout_width="124dp"
android:layout_height="105dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:src="#drawable/daccord" />
</RelativeLayout>
</LinearLayout>
And the Menu -java
package fr.libertyg.messervices;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.google.android.gms.ads.MobileAds;
public class Menu extends AppCompatActivity {
private ImageView distributeur;
private ImageView restaurant;
private ImageView courses;
private ImageView toilettes;
private ImageView essence;
private ImageView hopital;
AdView mAdView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
setContentView(R.layout.activity_menu);
this.distributeur = findViewById(R.id.distributeur);
distributeur.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent otherActivity = new Intent(getApplicationContext(), distributeur.class);
startActivity(otherActivity);
}
});
this.restaurant = findViewById(R.id.restaurant);
restaurant.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent otherActivity = new Intent(getApplicationContext(), restaurant.class);
startActivity(otherActivity);
}
});
this.courses = findViewById(R.id.courses);
courses.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent otherActivity = new Intent(getApplicationContext(), courses.class);
startActivity(otherActivity);
}
});
this.toilettes = findViewById(R.id.toilettes);
toilettes.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent otherActivity = new Intent(getApplicationContext(), toilettes.class);
startActivity(otherActivity);
}
});
this.essence = findViewById(R.id.essence);
essence.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent otherActivity = new Intent(getApplicationContext(), essence.class);
startActivity(otherActivity);
}
});
this.hopital = findViewById(R.id.hopital);
hopital.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent otherActivity = new Intent(getApplicationContext(), hopital.class);
startActivity(otherActivity);
}
});
MobileAds.initialize(this, "ca-app-pub-6520930039267956~4038950000");
mAdView = (AdView) findViewById(R.id.adView);
AdRequest adRequest = new AdRequest.Builder().build();
mAdView.loadAd(adRequest);
}
}
And the Menu xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:background="#drawable/fond"
android:orientation="vertical"
android:weightSum="10">
<RelativeLayout
android:layout_weight="1.5"
android:layout_width="match_parent"
android:layout_height="0dp">
<TextView
android:id="#+id/bienvenue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="#string/quoi"
android:textColor="#color/blanc"
android:textSize="30sp"/>
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="7.6">
<ImageView
android:id="#+id/distributeur"
android:layout_width="140dp"
android:layout_height="130dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_gravity="center_horizontal"
android:layout_marginStart="37dp"
android:layout_marginTop="29dp"
android:src="#drawable/distributeur" />
<ImageView
android:id="#+id/restaurant"
android:layout_width="140dp"
android:layout_height="130dp"
android:layout_alignParentEnd="true"
android:layout_alignParentTop="true"
android:layout_gravity="center_horizontal"
android:layout_marginEnd="37dp"
android:layout_marginTop="29dp"
android:src="#drawable/restaurant" />
<ImageView
android:id="#+id/courses"
top="#+id/distributeur"
android:layout_width="140dp"
android:layout_height="130dp"
android:layout_alignStart="#+id/distributeur"
android:layout_centerVertical="true"
android:layout_gravity="center_horizontal"
android:src="#drawable/courses" />
<ImageView
android:id="#+id/toilettes"
android:layout_width="140dp"
android:layout_height="130dp"
android:layout_alignStart="#+id/restaurant"
android:layout_alignTop="#+id/courses"
android:layout_gravity="center_horizontal"
android:src="#drawable/toilettes" />
<ImageView
android:id="#+id/essence"
android:layout_width="140dp"
android:layout_height="130dp"
android:layout_alignParentBottom="true"
android:layout_alignStart="#+id/distributeur"
android:layout_gravity="center_horizontal"
android:layout_marginBottom="28dp"
android:src="#drawable/essence" />
<ImageView
android:id="#+id/hopital"
android:layout_width="140dp"
android:layout_height="130dp"
android:layout_alignStart="#+id/restaurant"
android:layout_alignTop="#+id/essence"
android:layout_gravity="center_horizontal"
android:src="#drawable/hopital" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.9">
<com.google.android.gms.ads.AdView
xmlns:ads="http://schemas.android.com/apk/res-auto"
android:id="#+id/adView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
ads:adSize="BANNER"
ads:adUnitId="ca-app-pub-6520930039267956/3068657000" />
</RelativeLayout>
Thanks by advance for helping me.

In your app gradle make sure that libs use the same version, like:
implementation 'com.android.support:design:28.0.0-alpha1'
implementation 'com.android.support:cardview-v7:28.0.0-alpha1'
implementation 'com.android.support:appcompat-v7:28.0.0-alpha1'
implementation 'com.android.support:gridlayout-v7:28.0.0-alpha1'
You probably don't need all of them.
Make the changes and then click "Sync Now"

Solved it:
I had to add this to the manifest:
android:largeHeap="true"
And it worked fine.

Invalid session token on SignUp activity Android (Parse backend)

I've been tring for 2 days to get this to work but I couldn't,I keep getting this exception com.parse.ParseRequest$ParseRequestException: invalid session token.
I'm not an experienced android developper and it's my first time with parse so I'd appreciate it if you can post a detailed answer.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.parse.starter"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="9"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<application
android:name=".ParseApplication"
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<meta-data
android:name="com.parse.APPLICATION_ID"
android:value="#string/parse_app_id" />
<meta-data
android:name="com.parse.CLIENT_KEY"
android:value="#string/parse_client_key" />
<activity
android:name=".ParseStarterProjectActivity"
android:label="#string/app_name" >
</activity>
<activity
android:name=".SignUp"
android:label="#string/title_activity_sign_up" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
SignUp.java
package com.parse.starter;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.parse.ParseUser;
import com.parse.SignUpCallback;
public class SignUp extends Activity {
private Button sign_up_b;
private TextView email;
private TextView password;
private TextView password_conf;
private TextView firstName;
private TextView lastName;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sign_up);
sign_up_b = (Button)findViewById(R.id.email_sign_up_button);
email = (TextView)findViewById(R.id.email);
password = (TextView)findViewById(R.id.password);
password_conf = (TextView)findViewById(R.id.confirm_password);
firstName = (TextView)findViewById(R.id.first_name);
lastName = (TextView)findViewById(R.id.last_name);
sign_up_b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
attemptSignUp();
}
});
}
private void attemptSignUp(){
// Create the ParseUser
ParseUser user = new ParseUser();
// Set core properties
user.setUsername(email.getText().toString());
user.setPassword(password.getText().toString());
user.setEmail(email.getText().toString());
// Set custom properties
user.put("lName", lastName.getText().toString());
user.put("fName", firstName.getText().toString());
// Invoke signUpInBackground
user.signUpInBackground(new SignUpCallback() {
#Override
public void done(com.parse.ParseException e) {
if (e == null) {
// Hooray! Let them use the app now.
//Intent i = new Intent(getBaseContext(),Splash.class);
//startActivity(i);
} else {
e.printStackTrace();
// Sign up didn't succeed. Look at the ParseException
// to figure out what went wrong
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.sign_up, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
signup.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.parse.starter.SignUp">
<ScrollView android:id="#+id/sign_up_form" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout android:id="#+id/sign_up_infos" android:layout_width="match_parent"
android:layout_height="wrap_content" android:orientation="vertical">
<EditText android:id="#+id/first_name" android:layout_width="match_parent"
android:layout_height="wrap_content" android:hint="#string/prompt_first"
android:maxLines="1"
android:singleLine="true" />
<EditText android:id="#+id/last_name" android:layout_width="match_parent"
android:layout_height="wrap_content" android:hint="#string/prompt_last"
android:maxLines="1"
android:singleLine="true" />
<EditText android:id="#+id/email" android:layout_width="match_parent"
android:layout_height="wrap_content" android:hint="#string/prompt_email"
android:inputType="textEmailAddress" android:maxLines="1"
android:singleLine="true" />
<EditText android:id="#+id/password" android:layout_width="match_parent"
android:layout_height="wrap_content" android:hint="#string/prompt_password"
android:inputType="textPassword"
android:maxLines="1" android:singleLine="true" />
<EditText android:id="#+id/confirm_password" android:layout_width="match_parent"
android:layout_height="wrap_content" android:hint="#string/prompt_confirm_password"
android:inputType="textPassword"
android:maxLines="1" android:singleLine="true" />
<Button android:id="#+id/email_sign_up_button" style="?android:textAppearanceSmall"
android:layout_width="match_parent" android:layout_height="wrap_content"
android:layout_marginTop="16dp" android:text="#string/action_sign_up"
android:textStyle="bold" />
</LinearLayout>
</ScrollView>
</RelativeLayout>
I've tried the answer in this posts but I kept getting the same exception
com.parse.ParseRequest$ParseRequestException: invalid session token

For future reference all I had to do is uninstall the application from the emulator than run it again and the problem was solved.

You need to logout the user in Login\Signup view controllers.
Try this in viewDidLoad:
ParseUser.getCurrentUser().logOut();

app crash when i click sign in buttom

here is my my signupactivity & main activity and their xml
public class SignupActivity extends AppCompatActivity {
protected EditText mUsername;
protected EditText mPassword;
protected EditText mEmail;
protected Button nbutton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_signup);
mUsername = (EditText) findViewById(R.id.usernamefield);
mPassword = (EditText) findViewById(R.id.passwordtextfield);
mEmail = (EditText) findViewById(R.id.emailtextfield);
nbutton = (Button) findViewById(R.id.signbutton);
nbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view){
// Retrieve the text entered from the EditText
String usernametxt = mUsername.getText().toString();
String password = mPassword.getText().toString();
String email= mEmail.getText().toString();
// Force user to fill up the form
if (usernametxt.equals("") && password.equals("")) {
Toast.makeText(getApplicationContext(),
"Please complete the sign up form",
Toast.LENGTH_LONG).show();
} else {
// Save new user data into Parse.com Data Storage
ParseUser newUser = new ParseUser();
newUser.setUsername(usernametxt);
newUser.setPassword(password);
newUser.setEmail(email);
newUser.signUpInBackground(new SignUpCallback() {
#Override
public void done(ParseException e) {
//SUCESS
if (e!= null){
AlertDialog.Builder builder=new AlertDialog.Builder(SignupActivity.this);
builder.setMessage(e.getMessage()).setTitle(R.string.signup_error_title).setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}
else {
Intent intent= new Intent(SignupActivity.this,MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
}
});
}
}
});
}
it was suppose to get the information abt users and go to main activity from signupactivity.the app crashes when it get in put from users and press sign in...
here is the xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.josephvarkey996gmail.test1.SignupActivity" >
<TextView android:text="#string/hello_world" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/usernamefield"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginTop="89dp"
android:hint="#string/username_hint"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPassword"
android:ems="10"
android:id="#+id/passwordtextfield"
android:layout_centerHorizontal="true"
android:layout_below="#+id/usernamefield"
android:hint="#string/password_hint"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textEmailAddress"
android:ems="10"
android:id="#+id/emailtextfield"
android:hint="#string/email_hint"
android:layout_below="#+id/passwordtextfield"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/signup_hint"
android:id="#+id/signbutton"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
here is the main activity code
package com.josephvarkey996gmail.test1;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import com.parse.Parse;
import com.parse.ParseAnalytics;
import com.parse.ParseUser;
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Parse.enableLocalDatastore(this);
Parse.initialize(this, "XFigOgliUYKi9h5RanLfLkuKU14AG2f2NFQXADKI", "sMQBPkhZV5b74MEGpP3PdQ6eePWo5Y9O8lRcQvBP");
ParseAnalytics.trackAppOpenedInBackground(getIntent());
ParseUser currentUser = ParseUser.getCurrentUser();
if(currentUser==null) {
navigatetologin();
}
if(currentUser!=null)
{
Log.i(TAG ,currentUser.getUsername());
}
// Enable Local Datastore.
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
private void navigatetologin() {
Intent intent = new Intent(this, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
}
mainactivity xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin" tools:context=".MainActivity" >
<TextView android:text="#string/hello_world" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
android manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.josephvarkey996gmail.test1" >
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/Theme.AppCompat" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".SignupActivity"
android:label="#string/title_activity_signup" >
</activity>
<activity
android:name=".LoginActivity"
android:label="#string/title_activity_login" >
</activity>
</application>
</manifest>

We cannot help you until u post your logcat. As I don't have enough reputation to comment, I am writing this in answer.
Most common reason I saw people getting this error is:
They copy -paste this line from another class
R.id.usernamefield
So it will try to run the usernamefield of their other class which is not present here(note: eclipse will automatically import so they didn't get compilation errors). So to resolve your error you should delete the import and write proper R.id.xyz
But this is only shot in the dark until we see your logcat.

How to get rid of Bar in Android

I am new to developing but I have a problem
Here is the code of the stuff I believe you need to know
Main Activity
package com.mayubrand.basiccalculator;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity implements View.OnClickListener {
private Button circumferenceB, areaB, diameterB;
private TextView resultTxt, radiusTxt, headingTxt;
private EditText radiusTF ;
public void onCreate(){
this.requestWindowFeature(Window.FEATURE_NO_TITLE);}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
private void init(){
//Buttons
circumferenceB = (Button) findViewById(R.id.circumferenceB);
areaB = (Button) findViewById(R.id.areaB);
diameterB = (Button) findViewById(R.id.diameterB);
//Text Field (Edit Text)
radiusTF = (EditText) findViewById(R.id.radiusTF);
//Text (Text View)
resultTxt = (TextView) findViewById(R.id.resultTxt);
radiusTxt =(TextView) findViewById(R.id.radiusTxt);
headingTxt = (TextView) findViewById(R.id.radiusTxt);
//==============
//Listeners
circumferenceB.setOnClickListener(this);
areaB.setOnClickListener(this);
diameterB.setOnClickListener(this);
}
public void onClick(View view) {
String radiusEntered = radiusTF.getText().toString();
double pi = Math.PI;
int two = 2;
if(radiusEntered.equals("")) {
radiusTF.setText("");
}else{
switch (view.getId()){
case R.id.circumferenceB:
double circumference = Integer.parseInt(radiusEntered) * pi * two;
resultTxt.setText(String.valueOf(circumference));
break;
case R.id.areaB:
double area = pi * Integer.parseInt(radiusEntered) *Integer.parseInt(radiusEntered);
resultTxt.setText(String.valueOf(area));
break;
case R.id.diameterB:
double diameter = Integer.parseInt(radiusEntered) * 2;
resultTxt.setText(String.valueOf(diameter));
break;
}
}
}
}
Main Activity XML
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="MayU Circle Calulator"
android:id="#+id/headingTxt"
android:textColor="#ffffff"
android:textStyle="bold"
android:textSize="35dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Radius"
android:id="#+id/radiusTxt"
android:layout_below="#+id/headingTxt"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginTop="36dp"
android:textSize="23dp" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="number"
android:ems="10"
android:id="#+id/radiusTF"
android:layout_alignBottom="#+id/radiusTxt"
android:layout_alignRight="#+id/headingTxt"
android:layout_alignEnd="#+id/headingTxt" />
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/radiusTxt"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:weightSum="1">
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Find Circumference"
android:id="#+id/circumferenceB"
android:layout_weight="0.08" />
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Find Area"
android:id="#+id/areaB"
android:layout_weight="0.08" />
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Find Diameter"
android:id="#+id/diameterB"
android:layout_gravity="center_horizontal"
android:layout_weight="0.08" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Result"
android:id="#+id/resultTxt"
android:layout_gravity="center_horizontal"
android:layout_weight="0.08"
android:textSize="40dp" />
</LinearLayout>
Android Manifest
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="Circle Calculator"
android:theme="#style/AppTheme"
>
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
When I'm in the layout area where you arrange all your buttons and text and any other component you have visually it looks fine, however as soon as I launch it in the emulator or on my phone there is a bar black/brown bar that just stays there. How do I remove that?
One other thing on the side, how do I change the default color of buttons

My guess is that you are referring to the action bar.
If that is the case in your styles.xml change the AppTheme theme to NoActionBar.
<style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
<!-- Customize your theme here. -->
</style>
To change the default color of your buttons, you can use styles as well.

Android: Application is crashing On Startup

I am a novice and I'm just creating a simple Android app in which there are 2 buttons that take you to different pages when clicked, which have different functions.
However, my app crashes on start-up, simply saying
Unfortunately [app name] has stopped
and I don't understand
As I have barely made any changes to my MainActivity.java, the code seems to be well written, and eclipse displays no errors... Any help, please? I have searched around Stack, but I can't find anything specific to this...
Here is my MainActivity.java:
package com.example.helper;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**Called upon when the user clicks the 'Abbreviations' button*/
public void listDefinitions (View view){
Intent intent = new Intent(this, ListDefinitions.class);
startActivity(intent);
}
/**Called upon when the user clicks the 'Assistant' button*/
public void openAssistant (View view){
Intent intent = new Intent(this, Assistant.class);
startActivity(intent);
}
}
Here is my activity_main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.legittest.MainActivity" >
<TextView
android:id="#+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:text="#string/intro_title"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="21.5sp" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/title"
android:layout_centerHorizontal="true"
android:layout_marginTop="24dp"
android:text="#string/module_selection"
android:textAppearance="?android:attr/textAppearanceMedium" />
<Button
android:id="#+id/definitions_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/textView1"
android:layout_below="#+id/textView1"
android:layout_marginLeft="34dp"
android:layout_marginTop="111dp"
android:text="#string/definitions"
android:onClick="listDefinitions" />
<Button
android:id="#+id/assistant_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/definitions_button"
android:layout_centerHorizontal="true"
android:layout_marginTop="56dp"
android:text="#string/assistant"
android:onClick="openAssistant" />
<TextView
android:id="#+id/definitions_explainer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/definitions_button"
android:layout_centerHorizontal="true"
android:text="#string/definitions_info"
android:textAppearance="?android:attr/textAppearanceSmall"
android:textColor="#color/greycolor" />
<TextView
android:id="#+id/pa_explainer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="#+id/definitions_explainer"
android:layout_below="#+id/assistant_button"
android:text="#string/assistant_info"
android:textAppearance="?android:attr/textAppearanceSmall"
android:textColor="#color/greycolor" />
</RelativeLayout>
My ListDefinitions.java & Assistant.java are untouched at this point.
My Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.theocratichelper"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="19"
android:targetSdkVersion="21" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".ListDefinitions"
android:label="#string/title_activity_list_definitions"
android:parentActivityName=".MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.theocratichelper.MainActivity" />
</activity>
<activity
android:name=".PreachAssistant"
android:label="#string/title_activity_preach_assistant"
android:parentActivityName=".MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.theocratichelper.MainActivity" />
</activity>
</application>
</manifest>

It's your manifest, replace the "last" activity in your manifest by this :
<activity
android:name=".Assistant"
android:label="#string/title_activity_preach_assistant"
android:parentActivityName=".MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.theocratichelper.MainActivity" />
</activity>
Your class name is Assistant and not PreachAssistant i presume.

Just replace the last activity in Android Manifest by this.
<activity
android:name=".Assistant"
android:label="#string/title_activity_preach_assistant"
</activity>