Develop Reference

About Correct or Wrong answer

I want a test for 3-4 years old childs. I want if they click different apple , true count must plus one. And if they click one of same aplles false count must plus one. And click any apple the question and apples are must change.
My friend helped me and we did much of them. On clicks question and answers changing. But when click any apple wrong count plus one no matter it's true or false answer.
Can u pls help me?
We think we only have problems on if commands. He tried on it so much but couldn't solve the problem.
class file:
package tr.com.blogspot.etkinlikhavuzu.benimilkogretmenim;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.Random;
/**
* Created by erisk on 31.01.2017.
*/
public class AA extends Activity implements View.OnClickListener{
TextView soru,dogrusayi,yanlissayi;
ImageView secenek1,secenek2,secenek3;
ArrayList<Soru> sorular;
Random random;
int dogruSayisi,yanlisSayisi,sayac,dogruCevap;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.aa);
init();
sorulariYukle();
}
public void init(){
secenek1 = (ImageView) findViewById(R.id.secenek1);
secenek1.setOnClickListener(this);
secenek2 = (ImageView) findViewById(R.id.secenek2);
secenek2.setOnClickListener(this);
secenek3 = (ImageView) findViewById(R.id.secenek3);
secenek3.setOnClickListener(this);
soru = (TextView) findViewById(R.id.soru);
dogrusayi = (TextView) findViewById(R.id.dogrusayi);
yanlissayi = (TextView) findViewById(R.id.yanlissayi);
sorular = new ArrayList<Soru>();
random = new Random();
}
public void sorulariYukle(){
sorular.add(new Soru("Hangi Elma Yeşildir?",R.drawable.yesilelma,R.drawable.kirmizielma,R.drawable.kirmizielma,R.drawable.yesilelma));
sorular.add(new Soru("Hangi Elma Kırmızıdır?",R.drawable.kirmizielma,R.drawable.yesilelma,R.drawable.yesilelma,R.drawable.kirmizielma));
sorular.add(new Soru("Hangi Elma Yeşildir?",R.drawable.kirmizielma,R.drawable.yesilelma,R.drawable.kirmizielma,R.drawable.yesilelma));
sorular.add(new Soru("Hangi Elma Kırmızıdır?",R.drawable.yesilelma,R.drawable.yesilelma,R.drawable.kirmizielma,R.drawable.kirmizielma));
sorular.add(new Soru("Hangi Elma Yeşildir?",R.drawable.kirmizielma,R.drawable.kirmizielma,R.drawable.yesilelma,R.drawable.yesilelma));
sayac = random.nextInt(5);
soru.setText(sorular.get(sayac).getSoru());
secenek1.setImageResource(sorular.get(sayac).getSecenek1());
secenek2.setImageResource(sorular.get(sayac).getSecenek2());
secenek3.setImageResource(sorular.get(sayac).getSecenek3());
dogruCevap = sorular.get(sayac).getDogruCevap();
}
#Override
public void onClick(View view) {
switch (view.getId()){
case R.id.secenek1:
if(secenek1.getDrawable() == getResources().getDrawable(dogruCevap)){
dogruSayisi++;
dogrusayi.setText(String.valueOf(dogruSayisi));
}else{
yanlisSayisi++;
yanlissayi.setText(String.valueOf(yanlisSayisi));
}
sayac = random.nextInt(5);
soru.setText(sorular.get(sayac).getSoru());
secenek1.setImageResource(sorular.get(sayac).getSecenek1());
secenek2.setImageResource(sorular.get(sayac).getSecenek2());
secenek3.setImageResource(sorular.get(sayac).getSecenek3());
dogruCevap = sorular.get(sayac).getDogruCevap();
break;
case R.id.secenek2:
if(secenek2.getDrawable() == getResources().getDrawable(dogruCevap)){
dogruSayisi++;
dogrusayi.setText(String.valueOf(dogruSayisi));
}else{
yanlisSayisi++;
yanlissayi.setText(String.valueOf(yanlisSayisi));
}
sayac = random.nextInt(5);
soru.setText(sorular.get(sayac).getSoru());
secenek1.setImageResource(sorular.get(sayac).getSecenek1());
secenek2.setImageResource(sorular.get(sayac).getSecenek2());
secenek3.setImageResource(sorular.get(sayac).getSecenek3());
dogruCevap = sorular.get(sayac).getDogruCevap();
break;
case R.id.secenek3:
if(secenek3.getDrawable() == getResources().getDrawable(dogruCevap)){
dogruSayisi++;
dogrusayi.setText(String.valueOf(dogruSayisi));
}else{
yanlisSayisi++;
yanlissayi.setText(String.valueOf(yanlisSayisi));
}
sayac = random.nextInt(5);
soru.setText(sorular.get(sayac).getSoru());
secenek1.setImageResource(sorular.get(sayac).getSecenek1());
secenek2.setImageResource(sorular.get(sayac).getSecenek2());
secenek3.setImageResource(sorular.get(sayac).getSecenek3());
dogruCevap = sorular.get(sayac).getDogruCevap();
break;
}
}
}
xml file:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="tr.com.blogspot.etkinlikhavuzu.benimilkogretmenim.MainActivity">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="30dp">
<Button
android:id="#+id/dogru"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:background="#drawable/dogru" />
<Button
android:id="#+id/yanlis"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_below="#+id/dogru"
android:layout_marginTop="10dp"
android:background="#drawable/yanlis" />
<TextView
android:id="#+id/dogrusayi"
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_above="#+id/yanlis"
android:layout_toEndOf="#+id/dogru"
android:layout_toRightOf="#+id/dogru"
android:gravity="center"
android:text="#string/dogrusayi"
android:textColor="#006600"
android:textSize="30sp" />
<TextView
android:id="#+id/yanlissayi"
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_alignBottom="#+id/yanlis"
android:layout_toEndOf="#+id/yanlis"
android:layout_toRightOf="#+id/yanlis"
android:gravity="center"
android:text="#string/yanlissayi"
android:textColor="#990000"
android:textSize="30sp" />
<ImageView
android:id="#+id/secenek1"
android:layout_width="170dp"
android:layout_height="170dp"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<ImageView
android:id="#+id/secenek2"
android:layout_width="170dp"
android:layout_height="170dp"
android:layout_alignBottom="#+id/secenek1"
android:layout_centerHorizontal="true" />
<ImageView
android:id="#+id/secenek3"
android:layout_width="170dp"
android:layout_height="170dp"
android:layout_alignBottom="#+id/secenek2"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true" />
<TextView
android:id="#+id/soru"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/secenek2"
android:layout_marginBottom="18dp"
android:layout_toEndOf="#+id/dogrusayi"
android:layout_toRightOf="#+id/dogrusayi"
android:gravity="center"
android:text="Hangi Elma Yeşildir?"
android:textColor="#006600"
android:textSize="40sp"
android:textStyle="bold|italic" />
<TextView
android:id="#+id/siradaki"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:textColor="#000000" />
<TextView
android:id="#+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:text="1" />
</RelativeLayout>
</RelativeLayout>
And Soru.class file
package tr.com.blogspot.etkinlikhavuzu.benimilkogretmenim;
/**
* Created by erisk on 31.01.2017.
*/
public class Soru {
String soru;
int secenek1,secenek2,secenek3,dogruCevap;
public Soru(String soru, int secenek1, int secenek2, int secenek3, int dogruCevap) {
this.soru = soru;
this.secenek1 = secenek1;
this.secenek2 = secenek2;
this.secenek3 = secenek3;
this.dogruCevap = dogruCevap;
}
public String getSoru() {
return soru;
}
public void setSoru(String soru) {
this.soru = soru;
}
public int getSecenek1() {
return secenek1;
}
public void setSecenek1(int secenek1) {
this.secenek1 = secenek1;
}
public int getSecenek2() {
return secenek2;
}
public void setSecenek2(int secenek2) {
this.secenek2 = secenek2;
}
public int getSecenek3() {
return secenek3;
}
public void setSecenek3(int secenek3) {
this.secenek3 = secenek3;
}
public int getDogruCevap() {
return dogruCevap;
}
public void setDogruCevap(int dogruCevap) {
this.dogruCevap = dogruCevap;
}
}
Thank you so much

You are comparing drawables. which never matches.
Change your if(CONDITION) to following:
if(secenek1.getDrawable().getConstantState().equals(getResources().getDrawable(dogruCevap).getConstantState())).
same way for other two cases.

Spinner not showing selected or default choice

I've created a spinner that takes some user-generated strings (in my case classes - the school type) and displays them in a typical spinner way. My problem occurs when trying to select an item from the spinner. I can tap on the spinner and select the class, but the spinner never shows that I have the class selected. Before adding user-generated strings, I had a string-array xml file that worked perfectly.
I've tried adding notifyDataSetChanged() at the end of the onCreate() method, created a spinner layout with a transparent background and black text, and setting an setOnItemSelectedListener(). None of these worked, so I reverted code back to original state.
Screenshot of problem:
addAssignment.java
package com.nbdeg.unityplanner;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.Spinner;
import com.google.firebase.analytics.FirebaseAnalytics;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.nbdeg.unityplanner.data.Assignments;
import com.nbdeg.unityplanner.data.Classes;
import java.util.ArrayList;
public class addAssignment extends AppCompatActivity {
EditText mAssignmentName;
EditText mDueDate;
EditText mExtraInfo;
Spinner mDueClass;
SeekBar mPercentComplete;
int percentComplete = 0;
FirebaseAnalytics mFirebaseAnalytics;
DatabaseReference assignmentDb;
DatabaseReference classDb;
FirebaseUser user;
long assignmentCounter;
ArrayList<String> classList = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_assignment);
// Sets title to "Create an assignment"
try {getSupportActionBar().setTitle("Create An Assignment");}
catch (NullPointerException e) {
e.printStackTrace();
}
// Getting number of assignments (serves as assignment ID in database)
Bundle extras = getIntent().getExtras();
assignmentCounter = extras.getLong("counter");
// Finds firebase database
user = FirebaseAuth.getInstance().getCurrentUser();
mFirebaseAnalytics = FirebaseAnalytics.getInstance(this);
assignmentDb = FirebaseDatabase.getInstance().getReference().child("users").child(user.getUid()).child("assignments");
classDb = FirebaseDatabase.getInstance().getReference().child("users").child(user.getUid()).child("classes");
// Gets all classes
classDb.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot userSnapshot: dataSnapshot.getChildren()) {
Classes mClass = userSnapshot.getValue(Classes.class);
Log.i("Info", "Class loaded: " + mClass.getClassName());
classList.add(mClass.getClassName());
}
Log.i("Info", "Classes loaded: " + classList);
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.e("DB", "Error: " + databaseError.getMessage());
}
});
// Find view by ID calls
mAssignmentName = (EditText) findViewById(R.id.assignment_name);
mDueDate = (EditText) findViewById(R.id.due_date_edittext);
mExtraInfo = (EditText) findViewById(R.id.extra_homework_info);
mDueClass = (Spinner) findViewById(R.id.class_spinner);
mPercentComplete = (SeekBar) findViewById(R.id.percentComplete);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.spinner_layout, classList);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
mDueClass.setAdapter(adapter);
// Sets DueDate EditText to open a datepicker when clicked
new EditTextDatePicker(this, R.id.due_date_edittext);
mPercentComplete.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
percentComplete = progress;
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
}
// Adds a SAVE button to the Action Bar
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.save, menu);
return true;
}
// Gets and saves information when SAVE is clicked
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Getting information from views
String dueDate = mDueDate.getText().toString();
String assignmentName = mAssignmentName.getText().toString();
String extraInfo = mExtraInfo.getText().toString();
String dueClass = mDueClass.getItemAtPosition(mDueClass.getSelectedItemPosition()).toString();
mFirebaseAnalytics.logEvent("Assignment Created", null);
Log.i("DB", "Creating assignment named " + assignmentName);
assignmentDb.child(Long.toString(assignmentCounter)).setValue
(new Assignments(assignmentName, dueClass, dueDate, extraInfo, percentComplete));
/*
// Test to make sure info is being collected correctly.
Log.i("Class", dueClass);
Log.i("Due", dueDate);
Log.i("Name", homeworkName);
Log.i("Extra", extraInfo);
*/
// Bring user back to MainActivity
startActivity(new Intent(addAssignment.this, MainActivity.class));
return super.onOptionsItemSelected(item);
}
}
activity_add_assignment.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_add_homework"
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.nbdeg.unityplanner.addAssignment">
<EditText
android:layout_width="match_parent"
android:layout_height="40dp"
android:inputType="textCapSentences"
android:ems="10"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true"
android:id="#+id/assignment_name"
android:hint="Assignment Name"
android:padding="5dp"
android:textSize="18sp"
android:background="#null" />
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#c0c0c0"
android:layout_below="#id/assignment_name"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="43dp"
android:orientation="horizontal"
android:layout_below="#id/assignment_name"
android:layout_alignParentStart="true"
android:id="#+id/linearLayout">
<Spinner
android:layout_width="0dp"
android:layout_height="match_parent"
android:id="#+id/class_spinner"
android:theme="#android:style/Theme.Holo.Light.DarkActionBar"
android:layout_weight="1"
android:background="#null"/>
<View
android:layout_width="1dp"
android:layout_height="match_parent"
android:background="#c0c0c0"/>
<EditText
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:id="#+id/due_date_edittext"
android:padding="5dp"
android:focusable="false"
android:hint="Due Date"
android:textSize="16sp"
android:background="#null" />
</LinearLayout>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#c0c0c0"
android:layout_below="#id/linearLayout"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_below="#+id/linearLayout"
android:layout_alignParentStart="true"
android:id="#+id/percentCompleteLayout"
android:layout_marginTop="2dp"
android:layout_marginBottom="2dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Completion"
android:padding="5dp"
android:textColor="#color/black"
android:textSize="15sp"/>
<SeekBar
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/percentComplete"
android:layout_marginBottom="1dp"/>
</LinearLayout>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#c0c0c0"
android:layout_below="#id/percentCompleteLayout"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textMultiLine"
android:ems="10"
android:id="#+id/extra_homework_info"
android:hint="Extra Infomation"
android:textSize="16sp"
android:layout_below="#id/percentCompleteLayout"
android:layout_alignParentStart="true"
android:layout_marginTop="2dp"
android:padding="5dp"
android:background="#null" />
</RelativeLayout>
spinner_layout.xml*
<?xml version="1.0" encoding="utf-8"?>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="16sp"
android:gravity="left"
android:padding="5dip"
android:textColor="#android:color/black"
android:background="#android:color/transparent"
/>
I'm wondering if there is a way to fix this and have the spinner display the default / user choice. If you need any more of the code, all of it can be found in the GitHub. Thanks in advance for all answers!

Solution: Try loading the classes prior to starting the activity, for example in the MainActivity. Then pass the values along through an intent.
Example:
MainActivty.java
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Launch Add Homework Activity
Intent intent = new Intent(MainActivity.this, addAssignment.class);
intent.putExtra("classListNames", classListNames);
startActivity(intent);
...
classDb.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
classList.clear();
for (DataSnapshot userSnapshot: dataSnapshot.getChildren()) {
Classes mClass = userSnapshot.getValue(Classes.class);
Log.i(TAG, "Class loaded: " + mClass.getClassName());
classList.add(mClass);
classListNames.add(mClass.getClassName());
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.e(TAG, "Error: " + databaseError.getMessage());
}
});
addAssignment.java
// Gets class list
Bundle extras = getIntent().getExtras();
classListNames = extras.getStringArrayList("classListNames");
...
mDueClass = (Spinner) findViewById(R.id.class_spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.spinner_layout, classListNames);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
mDueClass.setAdapter(adapter);
Cause: After some debugging, I discovered the cause of the problem to be timing differences. The app would request the classes be sent, create the spinner, then load the classes. The difference in timing was milliseconds, but just enough to cause the problem.

How to change click event in android

Its been few days over to me, learning Android App development :
I have created an APK which is having two buttons (largeButton & smallButton) if you click on these button test will large and small accordingly.
What i am trying to do :
When i click second time button should change in previous mode i.e Vice Versa should happen.
Here is my code :
mainActivity:
package com.firstapk.helloworld;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity {
Button largButton;
Button smallButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
largButton = (Button) findViewById(R.id.largbutton);
smallButton = (Button) findViewById(R.id.smallbutton);
}
#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;
}
//public void getDisplay(View view){
public void largebuttonclick(View view){
try{
largButton.setTextSize(40);
}catch(Exception e){
Log.d("TestApp", e.getMessage());
}
}
//}
public void smallButtonClick(View view){
try{
smallButton.setTextSize(5);
}catch(Exception e){
Log.d("TestApp",e.getMessage());
}
}
}
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=".MainActivity" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
<Button
android:id="#+id/largbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/textView1"
android:layout_below="#+id/textView1"
android:layout_marginTop="96dp"
android:onClick="largebuttonclick"
android:text="#string/button_large" />
<Button
android:id="#+id/smallbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/textView1"
android:layout_below="#+id/textView1"
android:layout_marginTop="320dp"
android:onClick="smallButtonClick"
android:text="#string/button_small" />
</RelativeLayout>

As you did now it's right, if he click "Max size" he will see max size;
So maybe you want to use only one button which works like (+ and -)? If yes use one onClick and a boolean variable to save the current status (max size, small size).
private boolean maxSize; // false if small, true if max
public void onChangeSize(View view)
{
if (maxSize)//max->small
{
smallButton.setTextSize(5);
}
else//small->max
{
largButton.setTextSize(40);
}
maxSize = !maxSize;
}
Then android:onClick="onChangeSize" in the two buttons xml.
You could use the same approch for your current code, but it will work in the same way.

Treasure hunt has stopped working

When I ran the app the first activity worked but as soon as it went to the second activity it said treasure hunt has stopped working, and there was nothing under logcat or console. I am pretty sure it is a problem with level_1.java but can't figure out what. Please help thanks.
Main Activity:
package com.example.treasurehunt;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.util.Log;
import android.view.Menu;
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;
}
public void Start(View view) {
Log.d("hi", "hello");
Intent intent = new Intent(this, Level_1.class);
startActivity(intent);
finish();
}
}
Mainxml:
<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=".MainActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="Treasure Hunt" />
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="82dp"
android:text="Start"
android:onClick="Start" />
</RelativeLayout>
`
level_1java:
package com.example.treasurehunt;
import android.os.Bundle;
import android.app.Activity;
import android.content.SharedPreferences;
import android.util.Log;
import android.view.Menu;
import android.widget.EditText;
import android.widget.TextView;
public class Level_1 extends Activity {
private SharedPreferences settings;
private SharedPreferences.Editor editor;
TextView Clue = (TextView)findViewById(R.id.Clue);
EditText edittext = (EditText)findViewById(R.id.editText);
String hint;
String answer;
#Override
protected void onCreate(Bundle savedInstanceState) {
Log.d("hi","hello");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_level_1);
int level = settings.getInt("level", 1);
switch (level) {
case 1: level1();
break;
default:
break;
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.level_1, menu);
return true;
}
public void level1() {
editor.putInt("level", 1); // only needs to be done for level 1
editor.commit();
Clue.setText("Bartholdi was my creator, I carry fire and knowledge, what am I?");
hint = "July IV MDCCLXXVI";
answer = "statue of liberty";
}
public void answer() {
String useranswer = edittext.toString();
if (useranswer.equalsIgnoreCase(answer)) {// if they get the correct answer
int leveltest = settings.getInt("level", 1);
editor.putInt("level", leveltest+1); //adds one level to the current level
editor.commit();
}
}
public void hint() { //function that displays the hint
}
}
level_1 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=".Level_1" >
<TextView
android:id="#+id/Clue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="116dp"
android:text="Clue" />
<EditText
android:id="#+id/editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/Clue"
android:layout_centerHorizontal="true"
android:layout_marginTop="80dp"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="#+id/Submit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignRight="#+id/editText"
android:layout_marginBottom="50dp"
android:text="Submit"
android:onClick="answer"/>
<Button
android:id="#+id/Hint"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="#+id/Submit"
android:layout_alignBottom="#+id/Submit"
android:layout_alignLeft="#+id/editText"
android:text="Hint"
android:onClick="Hint"/>
</RelativeLayout>
Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.treasurehunt"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.treasurehunt.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="com.example.treasurehunt.Level_1"
android:label="#string/title_activity_level_1" >
</activity>
</application>
</manifest>

Seems you're having NullPointerException.
On the field declaration
TextView Clue = (TextView)findViewById(R.id.Clue);
EditText edittext = (EditText)findViewById(R.id.editText);
Move the assignments to in onCreate()
public class Level_1 extends Activity
{
// Other members ....
TextView Clue = (TextView)findViewById(R.id.Clue);
EditText edittext = (EditText)findViewById(R.id.editText);
#Override
protected void onCreate(Bundle savedInstanceState) {
Log.d("hi","hello");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_level_1);
// Assignemnts should be here
Clue = (TextView)findViewById(R.id.Clue);
edittext = (EditText)findViewById(R.id.editText);
int level = settings.getInt("level", 1);
switch (level) {
case 1: level1();
break;
default:
break;
}
}
}

Button OnClickListener not working

I am new to Android. I am trying to get input from the EditText and displaying it in TextView with the help of button. When I click the button nothing happens. Please help, here is my MainActivity.java code -
package com.example.addname;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
Button b1;
TextView v1;
EditText t1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b1 = (Button) findViewById(R.id.button1);
t1 = (EditText) findViewById(R.id.editText1);
v1 = (TextView) findViewById(R.id.textView1);
b1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if(t1.getText().toString()=="")
{
v1.setText(t1.getText().toString());
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
and 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"
tools:context=".MainActivity" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="#string/hello_world" />
<EditText
android:id="#+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginTop="25dp"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="#+id/textView1"
android:layout_below="#+id/editText1"
android:layout_marginTop="48dp"
android:text="Button" />
</RelativeLayout>

Instead of
if(t1.getText().toString()=="")
{
v1.setText(t1.getText().toString());
}
You can use
if(t1.getText().isEmpty()) // isEmpty() is only available from API 9 and Above
{
v1.setText(t1.getText().toString());
}
or this
if(t1.getText().trim().length == 0)
{
v1.setText(t1.getText().toString());
}
Don't compare strings using ==. You're actually comparing reference of an object. To compare strings, use equals() method.

I'd recommend comparing strings with .equals() since Objects compared with == usually fails (== compares references, not Object content).
if(t1.getText().toString().equals("")))
in your case though,since you're comparing an empty String, you can also use
if (t1.getText().toString().length == 0)
Then note that once you set the text, you're setting v1's text to an empty string since your logic indicates that only upon an empty string you set v1's text. So I'd recommend getting rid of the if altogether:
#Override
public void onClick(View arg0) {
v1.setText(t1.getText().toString());
}