We Keep Coding

Android Development. RadioButton keeps unselecting

I am building a little quiz app and let's say on Question 1, I select option B, then submit and the quiz gives me the next question. However for question 2 if I try to select B, the RadioButton quickly unchecks itself and it is completely uncheckable, until I select another radio button and then try B again. The pattern is, whatever option I selected in the previous question, is uncheckable in the next question unless I click on a different radiobutton and then try again. I'm attaching my code. Any help please?
public class MainActivity extends AppCompatActivity {
QuestionBank allQuestions = new QuestionBank();
String pickedAnswer = "", correctAnswer = "";
final int numberOfQuestions = allQuestions.list.size();
int questionNumber = 0;
boolean noSelection = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
nextQuestion();
}
private void nextQuestion() {
if (questionNumber <= numberOfQuestions - 1) {
TextView questionLabel = (TextView) findViewById(R.id.question_text_view);
String fullQuestion = allQuestions.list.get(questionNumber).questionSet.get("question").toString();
fullQuestion += "\n\na) " + allQuestions.list.get(questionNumber).questionSet.get("a");
fullQuestion += "\nb) " + allQuestions.list.get(questionNumber).questionSet.get("b");
fullQuestion += "\nc) " + allQuestions.list.get(questionNumber).questionSet.get("c");
fullQuestion += "\nd) " + allQuestions.list.get(questionNumber).questionSet.get("d");
correctAnswer = allQuestions.list.get(questionNumber).questionSet.get("answer").toString();
questionLabel.setText(fullQuestion);
questionNumber++;
} else {
restart();
}
}
public void getSelectedAnswer() {
RadioButton radio_1 = (RadioButton) findViewById(R.id.option1_button);
RadioButton radio_2 = (RadioButton) findViewById(R.id.option2_button);
RadioButton radio_3 = (RadioButton) findViewById(R.id.option3_button);
RadioButton radio_4 = (RadioButton) findViewById(R.id.option4_button);
if (radio_1.isChecked()) {
pickedAnswer = "a";
radio_1.setChecked(false);
} else if (radio_2.isChecked()) {
pickedAnswer = "b";
radio_2.setChecked(false);
} else if (radio_3.isChecked()) {
pickedAnswer = "c";
radio_3.setChecked(false);
} else if (radio_4.isChecked()) {
pickedAnswer = "d";
radio_4.setChecked(false);
} else {
noSelection = true;
}
}
public void submitAnswer(View view) {
getSelectedAnswer();
if (noSelection) {
AlertDialog.Builder a_builder = new AlertDialog.Builder(this);
a_builder.setMessage("Please select an answer!");
a_builder.show();
noSelection = false;
} else {
checkAnswer();
nextQuestion();
}
}
public void checkAnswer() {
if (correctAnswer == pickedAnswer) {
AlertDialog.Builder a_builder = new AlertDialog.Builder(this);
a_builder.setMessage("Right Answer!");
a_builder.show();
} else {
AlertDialog.Builder a_builder = new AlertDialog.Builder(this);
a_builder.setMessage("Wrong Answer!");
a_builder.show();
}
pickedAnswer = "";
correctAnswer = "";
}
public void restart() {
questionNumber = 0;
//Collections.shuffle(allQuestions.list);
nextQuestion();
}
}

call setChecked(false) on all the buttons after submitting or before showing next question

Disabling onClick until int = something

public class MainActivity extends AppCompatActivity {
int foulCounterA = 0;
int scoreOnePointTeamA = 0;
int periodCount = 0;
private TextView tv1;
private TextView period;
private Button startbtn, cancelbtn;
private ToggleButton togbtn;
private boolean isPaused = false;
private boolean isCanceled = false;
private long remainingTime = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv1 = (TextView) findViewById(R.id.tv1);
period = (TextView) findViewById(R.id.period_number);
startbtn = (Button) findViewById(R.id.startBtn);
cancelbtn = (Button) findViewById(R.id.cancelBtn);
togbtn = (ToggleButton) findViewById(R.id.togBtn);
cancelbtn.setEnabled(false);
togbtn.setEnabled(false);
startbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
foulCounterA = 0;
foulCounterB = 0;
displayForTeamAFoul(foulCounterA);
displayForTeamBFoul(foulCounterB);
if (periodCount < 3)
periodCount = periodCount + 1;
else periodCount = 4;
period.setText("Period " + periodCount);
startbtn.setEnabled(false);
cancelbtn.setEnabled(true);
togbtn.setEnabled(true);
isPaused = false;
isCanceled = false;
long millisInFuture = 20000; /////20sec
long countDownInterval = 1000; /////1sec
new CountDownTimer(millisInFuture, countDownInterval) {
#Override
public void onTick(long millisUntilFinished) {
if (isPaused || isCanceled) {
cancel();
} else {
tv1.setText("" + millisUntilFinished / 1000);
remainingTime = millisUntilFinished;
}
}
#Override
public void onFinish() {
startbtn.setEnabled(true);
togbtn.setEnabled(false);
if (periodCount < 4)
tv1.setText("Times up!");
else tv1.setText("Game Over!");
}
}.start();
}
});
togbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (togbtn.isChecked()) {
isPaused = true;
} else {
isPaused = false;
long millisInFuture = remainingTime;
long countDownInterval = 1000; /////1sec
new CountDownTimer(millisInFuture, countDownInterval) {
#Override
public void onTick(long millisUntilFinished) {
if (isPaused || isCanceled) {
cancel();
} else {
tv1.setText("" + millisUntilFinished / 1000);
remainingTime = millisUntilFinished;
}
}
#Override
public void onFinish() {
startbtn.setEnabled(true);
togbtn.setEnabled(false);
if (periodCount < 4)
tv1.setText("Times up!");
else tv1.setText("Game Over!");
}
}.start();
}
}
});
cancelbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
isCanceled = true;
period.setText("Period");
tv1.setText("Timer");
startbtn.setEnabled(true);
togbtn.setEnabled(false);
cancelbtn.setEnabled(false);
foulCounterA = 0;
foulCounterB = 0;
periodCount = 0;
displayForTeamAFoul(foulCounterA);
displayForTeamBFoul(foulCounterB);
}
});
}
public void onePointForTeamA(View v) {
scoreTeamA = scoreTeamA + 1;
scoreOnePointTeamA = scoreOnePointTeamA + 1;
displayForTeamA(scoreTeamA);
displayForTeamAOnePoint(scoreOnePointTeamA);
}
public void foulCountForTeamA(View v) {
if (foulCounterA < 5)
foulCounterA = foulCounterA + 1;
else
foulCounterA = 5;
displayForTeamAFoul(foulCounterA);
}
public void displayForTeamAOnePoint(int score) {
TextView scoreView = (TextView) findViewById(R.id.team_a_score_1_point);
scoreView.setText(String.valueOf(score));
}
public void displayForTeamAFoul(int score) {
TextView scoreView = (TextView) findViewById(R.id.team_a_foul);
scoreView.setText(String.valueOf(score));
}
}
I wanted to make the java code as simple as I can so I've just added the lines for my question. What I'm trying to do is
android:onClick="onePointForTeamA"make this button only clickable when foulCounterA = 5 Failed to add if (foulCounterA = 5); inside public void foulCountForTeamA(View v) {
It gave me an error that way. Says required: boolean, found: int.
What should I do with the code? Any help will be appreeciated

Regarding your concrete question, the syntax of if (foulCounterA = 5); is wrong, because the equation check is have to made by == operator.
So the correct syntax would be if (foulCounterA == 5);
As #OH GOD SPIDERS wrote in the comment, you should check the basics of java operators.
Also I recommend You to search for the answer before asking a new question.

[HELP]FATAL EXCEPTION: main java.lang.NullPointerException [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 6 years ago.
public class MainActivity extends Activity {
private static final String TAG = "MainActivity";
ProductDatabase.ProductDatabaseHelper controller = new ProductDatabase.ProductDatabaseHelper(this);
EditText mBarcodeEdit;
EditText mFormatEdit;
EditText mTitleEdit;
EditText mPriceEdit;
private static final int ZBAR_SCANNER_REQUEST = 0;
private static final int ZBAR_QR_SCANNER_REQUEST = 1;
private static final ProductData mProductData = new ProductData();
Button mScanButton;
Button mAddButton;
Button mSelectButton;
Button mExportButton;
Button btnimport;
ProductDatabase mProductDb;
ListView ls;
TextView infotext;
File file = null;
// DatabaseHelper dbhelper = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ls = (ListView) findViewById(R.id.placeslist);
mBarcodeEdit = (EditText) findViewById(R.id.barcodeEdit);
mFormatEdit = (EditText) findViewById(R.id.codeFormatEdit);
mTitleEdit = (EditText) findViewById(R.id.titleEdit);
mPriceEdit = (EditText) findViewById(R.id.priceEdit);
mScanButton = (Button) findViewById(R.id.scan_btn);
mAddButton = (Button) findViewById(R.id.addButton);
mSelectButton = (Button) findViewById(R.id.selelctButton);
mProductDb = new ProductDatabase(this); // not yet shown
infotext = (TextView) findViewById(R.id.txtresulttext);
mExportButton = (Button) findViewById(R.id.exportbtn);
mSelectButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(MainActivity.this, product_list.class);
startActivity(i);
}
});
mAddButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String barcode = mBarcodeEdit.getText().toString();
String format = mFormatEdit.getText().toString();
String title = mTitleEdit.getText().toString();
String price = mPriceEdit.getText().toString();
String errors = validateFields(barcode, format, title, price);
if (errors.length() > 0) {
showInfoDialog(MainActivity.this, "Please fix errors", errors);
} else {
mProductData.barcode = barcode;
mProductData.format = format;
mProductData.title = title;
mProductData.price = new BigDecimal(price);
mProductDb.insert(mProductData);
showInfoDialog(MainActivity.this, "Success", "Product saved successfully");
resetForm();
}
}
});
mExportButton.setOnClickListener(new View.OnClickListener() {
SQLiteDatabase sqldb = controller.getReadableDatabase(); //My Database class
Cursor c =null;
#Override
public void onClick(View view) { //main code begins here
try {
c = sqldb.rawQuery("select * from spot_pay.db", null);
int rowcount = 0;
int colcount = 0;
File sdCardDir = Environment.getExternalStorageDirectory();
String filename = "MyBackUp.csv";
// the name of the file to export with
File saveFile = new File(sdCardDir, filename);
FileWriter fw = new FileWriter(saveFile);
BufferedWriter bw = new BufferedWriter(fw);
rowcount = c.getCount();
colcount = c.getColumnCount();
if (rowcount > 0) {
c.moveToFirst();
for (int i = 0; i < colcount; i++) {
if (i != colcount - 1) {
bw.write(c.getColumnName(i) + ",");
} else {
bw.write(c.getColumnName(i));
}
}
bw.newLine();
for (int i = 0; i < rowcount; i++) {
c.moveToPosition(i);
for (int j = 0; j < colcount; j++) {
if (j != colcount - 1)
bw.write(c.getString(j) + ",");
else
bw.write(c.getString(j));
}
bw.newLine();
}
bw.flush();
infotext.setText("Exported Successfully.");
}
} catch (Exception ex) {
if (sqldb.isOpen()) {
sqldb.close();
infotext.setText(ex.getMessage().toString());
}
} finally {
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu, menu);
return true;
}
private void showInfoDialog(Context context, String title, String information) {
new AlertDialog.Builder(context)
.setMessage(information)
.setTitle(title)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
}).show();
}
private void resetForm() {
// TODO Auto-generated method stub
mBarcodeEdit.getText().clear();
mFormatEdit.getText().clear();
mTitleEdit.getText().clear();
mPriceEdit.getText().clear();
}
public void launchScanner(View v) {
if (isCameraAvailable()) {
Intent intent = new Intent(this, ZBarScannerActivity.class);
startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
} else {
Toast.makeText(this, "Rear Facing Camera Unavailable", Toast.LENGTH_SHORT).show();
}
}
public void launchQRScanner(View v) {
if (isCameraAvailable()) {
Intent intent = new Intent(this, ZBarScannerActivity.class);
intent.putExtra(ZBarConstants.SCAN_MODES, new int[]{Symbol.QRCODE});
startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
} else {
Toast.makeText(this, "Rear Facing Camera Unavailable", Toast.LENGTH_SHORT).show();
}
}
public boolean isCameraAvailable() {
PackageManager pm = getPackageManager();
return pm.hasSystemFeature(PackageManager.FEATURE_CAMERA);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case ZBAR_SCANNER_REQUEST:
case ZBAR_QR_SCANNER_REQUEST:
if (resultCode == RESULT_OK) {
mBarcodeEdit.setText(data.getStringExtra(ZBarConstants.SCAN_RESULT));
// Toast.makeText(this, "Scan Result = " + data.getStringExtra(ZBarConstants.SCAN_RESULT), Toast.LENGTH_SHORT).show();
} else if (resultCode == RESULT_CANCELED && data != null) {
String error = data.getStringExtra(ZBarConstants.ERROR_INFO);
if (!TextUtils.isEmpty(error)) {
Toast.makeText(this, error, Toast.LENGTH_SHORT).show();
}
}
break;
}
}
private static String validateFields(String barcode, String format,
String title, String price) {
StringBuilder errors = new StringBuilder();
if (barcode.matches("^\\s*$")) {
errors.append("Barcode required\n");
}
if (format.matches("^\\s*$")) {
errors.append("Format required\n");
}
if (title.matches("^\\s*$")) {
errors.append("Title required\n");
}
if (!price.matches("^-?\\d+(.\\d+)?$")) {
errors.append("Need numeric price\n");
}
return errors.toString();
}
}

I think string may be null somewhere. Please type something in textfield or check for null string.

Global variable reset to 0

I have a global variable inext set to a random value correctly before a call to setWordsQuestion(). As soon as I enter setWordsQuestion() the value is 0. Do you know how I can debug this?
and reset to 0:
Here is the java file:
public class ExercisesWords_fragment extends Fragment {
static Context context;
String login;
String fileMenuCard = null;
InputStreamReader isr;
InputStream fIn;
BufferedReader input_card = null;
int level, lang;
int ihelp;
String fileLogin;
RadioGroup rg;
RadioButton rb1, rb2, rb3, rb4;
EditText edt;
TextView txt, question;
Button validation, next, help;
int MAXWORDS = 42;
String[] words_questions = new String[MAXWORDS];
String[] words_cb1 = new String[MAXWORDS];
String[] words_cb2 = new String[MAXWORDS];
String[] words_cb3 = new String[MAXWORDS];
String[] words_cb4 = new String[MAXWORDS];
String[] words_response = new String[MAXWORDS];
int[] words_level = new int[MAXWORDS];
int MAXTEMP = 5;
int[] tmp;
int inext_question, inext;
public ExercisesWords_fragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.exercises_words_fragment, container, false);
}
#Override
public void onAttach(Activity activity){
super.onAttach(activity);
}
#Override
public void onPause() {
closeFileWords();
super.onPause();
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
context = getActivity().getApplicationContext();
fileMenuCard = "words";
login = getArguments().getString("login");
lang = getArguments().getInt("lang");
level = getArguments().getInt("level");
fileLogin = login + "_words.txt";
initViewFind();
initExerciseWords();
nextWordsQuestion();
getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
edt.setOnEditorActionListener(new TextView.OnEditorActionListener() {
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
if ((event != null && (event.getKeyCode() == KeyEvent.KEYCODE_NUMPAD_ENTER)) || (actionId == EditorInfo.IME_ACTION_DONE)) {
validateResponse();
}
return false;
}
});
validation.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
validateResponse();
}
});
next.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
nextWordsQuestion();
}
});
help.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
ihelp = 1;
hideKeyboard();
helpWords();
ihelp = 0;
}
});
}
private void drawBTN() {
if(lang == 0) {
validation.setText(R.string.pro_validation);
validation.setVisibility(View.VISIBLE);
next.setText(R.string.next);
next.setVisibility(View.VISIBLE);
help.setText(R.string.help);
help.setVisibility(View.VISIBLE);
}
else {
validation.setText(R.string.pro_validation_fr);
validation.setVisibility(View.VISIBLE);
next.setText(R.string.next_fr);
next.setVisibility(View.VISIBLE);
help.setText(R.string.help_fr);
help.setVisibility(View.VISIBLE);
}
}
private void nextWordsQuestion() {
int inext;
Random r;
r = new Random();
inext = r.nextInt(MAXWORDS);
if (inext_question < MAXTEMP) {
tmp[inext_question] = inext;
inext_question++;
setWordsQuestion();
return;
}
for (int i = 0; i < MAXTEMP; i++) {
if (inext == tmp[i]) {
r = new Random();
inext = r.nextInt(MAXWORDS);
i--;
}
}
System.arraycopy(tmp, 1, tmp, 0, MAXTEMP - 1);
tmp[MAXTEMP - 1] = inext;
setWordsQuestion();
}
private void setWordsQuestion(){
question.setText(words_questions[inext]);
question.setVisibility(View.VISIBLE);
edt.setText("");
rb1.setText(words_cb1[inext]);
rb2.setText(words_cb2[inext]);
rb3.setText(words_cb3[inext]);
rb4.setText(words_cb4[inext]);
rb1.setVisibility(View.INVISIBLE);
rb2.setVisibility(View.INVISIBLE);
rb3.setVisibility(View.INVISIBLE);
rb4.setVisibility(View.INVISIBLE);
rg.clearCheck();
hideKeyboard();
}
private void validateResponse(){
String response;
if(ihelp == 1){
int sel = rg.getCheckedRadioButtonId();
if(sel < 0) return;
RadioButton rb = (RadioButton) getActivity().findViewById(sel);
response = rb.getText().toString();
}
else {
response = edt.getText().toString();
}
TextView resp = (TextView) getActivity().findViewById(R.id.resp_words);
if(response.equals(words_response[inext])) {
next.setTextColor(Color.GREEN);
next.setVisibility(View.VISIBLE);
resp.setText(R.string.resp_card);
resp.setTextColor(Color.GREEN);
resp.setVisibility(View.VISIBLE);
}
else {
resp.setText(R.string.resp_card_no);
resp.setTextColor(Color.RED);
resp.setVisibility(View.VISIBLE);
}
}
private void helpWords(){
hideKeyboard();
rb1.setText(words_cb1[inext]);
rb1.setVisibility(View.VISIBLE);
rb2.setText(words_cb2[inext]);
rb2.setVisibility(View.VISIBLE);
rb3.setText(words_cb3[inext]);
rb3.setVisibility(View.VISIBLE);
rb4.setText(words_cb4[inext]);
rb4.setVisibility(View.VISIBLE);
}
private void hideKeyboard(){
EditText e = (EditText) getActivity().findViewById(R.id.words_answer);
InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(e.getWindowToken(), 0);
}
private void openWords(){
String l = null;
try {
if (lang == 0)
fIn = context.getResources().getAssets()
.open(fileMenuCard+".txt", Context.MODE_PRIVATE);
else
fIn = context.getResources().getAssets()
.open(fileMenuCard+"_fr.txt", Context.MODE_PRIVATE);
isr = new InputStreamReader(fIn);
input_card = new BufferedReader(isr);
} catch (Exception e) {
e.getMessage();
}
for(int i=0;i<MAXWORDS;i++){
try {
l = input_card.readLine();
} catch (IOException e) {
e.printStackTrace();
}
if (l != null) {
StringTokenizer tokens = new StringTokenizer(l, ";");
words_questions[i] = tokens.nextToken();
words_level[i] = Integer.valueOf(tokens.nextToken());
words_cb1[i] = tokens.nextToken();
words_cb2[i] = tokens.nextToken();
words_cb3[i] = tokens.nextToken();
words_cb4[i] = tokens.nextToken();
words_response[i] = tokens.nextToken();
}
}
}
private void closeFileWords(){
try {
fIn.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
isr.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
input_card.close();
} catch (IOException e) {
e.printStackTrace();
}
}
private void initExerciseWords(){
tmp = new int[MAXTEMP];
for(int i=0;i<MAXTEMP;i++)
tmp[i] = -1;
inext_question = 0;
openWords();
}
private void initViewFind(){
edt = (EditText) getActivity().findViewById(R.id.words_answer);
txt = (TextView) getActivity().findViewById(R.id.title_words);
validation = (Button) getActivity().findViewById(R.id.validation_words);
next = (Button) getActivity().findViewById(R.id.next_words);
help = (Button) getActivity().findViewById(R.id.help_words);
question = (TextView) getActivity().findViewById(R.id.words_question);
rg = (RadioGroup) getActivity().findViewById(R.id.rg_words);
rb1 = (RadioButton) getActivity().findViewById(R.id.radio1_words);
rb2 = (RadioButton) getActivity().findViewById(R.id.radio2_words);
rb3 = (RadioButton) getActivity().findViewById(R.id.radio3_words);
rb4 = (RadioButton) getActivity().findViewById(R.id.radio4_words);
if(lang == 0)
txt.setText(R.string.words_fr);
else
txt.setText(R.string.words_title_fr);
}
}

You are setting a local variable that hides the instance member :
private void nextWordsQuestion() {
int inext; // remove this line
...
inext = r.nextInt(MAXWORDS);
...
setWordsQuestion();
...
}
Therefore setWordsQuestion, which uses the instance member, doesn't see the value you set in nextWordsQuestion.

When you assign a random value to inext, you are assigning it to a local variable, not the global one.
To fix, simply remove the local variable.
private void nextWordsQuestion() {
//int inext;
Random r;
r = new Random();
inext = r.nextInt(MAXWORDS);
if (inext_question < MAXTEMP) {
tmp[inext_question] = inext;
inext_question++;
setWordsQuestion();
return;
}

Error while working in Android Studio

This is an application coding for a basic calculator using Android Studio. There is en error just before the end of the coding. I have mentioned the error in the coding directly.
Can some please explain what the error is all about and how I can go about rectifying the same?
package com.example.asish.calculator;
import android.app.Activity;
import android.support.v7.app.ActionBarActivity;
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 android.widget.Toast;
public class MainActivity extends Activity {
Button bone, btwo, bthree, bfour, bfive, bsix, bseven, beight, bnine, bzero, badd, bsub, bmul, bdiv, bclear,
bce, bequal;
TextView txt;
String s = "", s1 = "", s2 = "", s3 = "";
int i = 0, i1 = 0, c = -1, flag_disable = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bone = (Button) findViewById(R.id.one);
btwo = (Button) findViewById(R.id.two);
bthree = (Button) findViewById(R.id.three);
bfour = (Button) findViewById(R.id.four);
bfive = (Button) findViewById(R.id.five);
bsix = (Button) findViewById(R.id.six);
bseven = (Button) findViewById(R.id.seven);
beight = (Button) findViewById(R.id.eight);
bnine = (Button) findViewById(R.id.nine);
bzero = (Button) findViewById(R.id.zero);
bce = (Button) findViewById(R.id.ce);
bequal = (Button) findViewById(R.id.equals);
bclear = (Button) findViewById(R.id.clear);
badd = (Button) findViewById(R.id.plus);
bsub = (Button) findViewById(R.id.minus);
bdiv = (Button) findViewById(R.id.division);
bmul = (Button) findViewById(R.id.multiply);
bone.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"1");
s = "";
}
});
btwo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"2");
s = "";
}
});
bthree.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"3");
s = "";
}
});
bfour.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"4");
s = "";
}
});
bfive.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"5");
s = "";
}
});
bsix.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"6");
s = "";
}
});
bseven.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"7");
s = "";
}
});
beight.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"8");
s = "";
}
});
bnine.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+9);
s = "";
}
});
bzero.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if(s.equals("+")||s.equals("-")||s.equals("/")||s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s+"0");
s = "";
}
});
badd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tmp = (String) txt.getText();
if(!tmp.equals("+")&&!tmp.equals("-")&&!tmp.equals("*")&&!tmp.equals("/"))
s1=tmp;
c=0;
txt.setText("+");
}
});
bsub.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tmp = (String) txt.getText();
if(!tmp.equals("+")&&!tmp.equals("-")&&!tmp.equals("*")&&!tmp.equals("/"))
s1=tmp;
c=2;
txt.setText("-");
}
});
bmul.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tmp = (String) txt.getText();
if(!tmp.equals("+")&&!tmp.equals("-")&&!tmp.equals("*")&&!tmp.equals("/"))
s1=tmp;
c=3;
txt.setText("*");
}
});
bdiv.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tmp = (String) txt.getText();
if(!tmp.equals("+")&&!tmp.equals("-")&&!tmp.equals("*")&&!tmp.equals("/"))
s1=tmp;
c=2;
txt.setText("/");
}
});
bequal.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(s1=="+"||s1=="-"||s1=="/"||s1=="*") {
i = 0;
}
else if(s1==null|| s1==""||s1.trim().length()==0) {
i = i;
}
else {
i = Integer.parseInt(s1);
}
s2 = (String) txt.getText();
if(s2=="+"||s2=="-"||s2=="/"||s2=="*") {
i1 = 0;
}
else if(s2==null|| s2==""||s2.trim().length()==0) {
i1 = 0;
}
else {
i1 = Integer.parseInt(s2);
}
if(c==0) {
i = i + i1;
}
else if(c==1) {
i = i - i1;
}
else if(c==2){
if(i1==0) {
Toast.makeText(getApplicationContext(), "Invalid Input", Toast.LENGTH_LONG).show();
i = 0;
}
else{
i = i / i1;
}
}
else if(c==3) {
i = i * i1;
}
else {
i = 0;
}
txt.setText(i+"");
}
});
bclear.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*") || s.equals("")) {
i = 0;
} else {
i = Integer.parseInt(s);
i = i / 10;
}
if (i == 0) {
txt.setText("");
} else {
txt.setText(i + "");
}
s = null;
}
});
bce.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
txt.setText("");
i = 0;
i1 = 0;
s1 = "";
s2 = "";
c = -1;
}
});
}
} --> Error in this line. Error message - Class or interface expected.
#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;
}
#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);
}
}

Looks like you have to delete one of the brackets where you noted the error. That should fix the issue.

Try this code to your tool.
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.vcs.YOURPACKAGE.R;(it will be import automatically)
public class MainActivity extends AppCompatActivity {
Button bone, btwo, bthree, bfour, bfive, bsix, bseven, beight, bnine, bzero, badd, bsub, bmul, bdiv, bclear,
bce, bequal;
TextView txt;
String s = "", s1 = "", s2 = "", s3 = "";
int i = 0, i1 = 0, c = -1, flag_disable = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bone = (Button) findViewById(R.id.one);
btwo = (Button) findViewById(R.id.two);
bthree = (Button) findViewById(R.id.three);
bfour = (Button) findViewById(R.id.four);
bfive = (Button) findViewById(R.id.five);
bsix = (Button) findViewById(R.id.six);
bseven = (Button) findViewById(R.id.seven);
beight = (Button) findViewById(R.id.eight);
bnine = (Button) findViewById(R.id.nine);
bzero = (Button) findViewById(R.id.zero);
bce = (Button) findViewById(R.id.ce);
bequal = (Button) findViewById(R.id.equals);
bclear = (Button) findViewById(R.id.clear);
badd = (Button) findViewById(R.id.plus);
bsub = (Button) findViewById(R.id.minus);
bdiv = (Button) findViewById(R.id.division);
bmul = (Button) findViewById(R.id.multiply);
bone.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "1");
s = "";
}
});
btwo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "2");
s = "";
}
});
bthree.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "3");
s = "";
}
});
bfour.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "4");
s = "";
}
});
bfive.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "5");
s = "";
}
});
bsix.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "6");
s = "";
}
});
bseven.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "7");
s = "";
}
});
beight.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "8");
s = "";
}
});
bnine.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + 9);
s = "";
}
});
bzero.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*")) {
txt.setText("");
s = "";
}
txt.setText(s + "0");
s = "";
}
});
badd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tmp = (String) txt.getText();
if (!tmp.equals("+") && !tmp.equals("-") && !tmp.equals("*") && !tmp.equals("/"))
s1 = tmp;
c = 0;
txt.setText("+");
}
});
bsub.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tmp = (String) txt.getText();
if (!tmp.equals("+") && !tmp.equals("-") && !tmp.equals("*") && !tmp.equals("/"))
s1 = tmp;
c = 2;
txt.setText("-");
}
});
bmul.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tmp = (String) txt.getText();
if (!tmp.equals("+") && !tmp.equals("-") && !tmp.equals("*") && !tmp.equals("/"))
s1 = tmp;
c = 3;
txt.setText("*");
}
});
bdiv.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tmp = (String) txt.getText();
if (!tmp.equals("+") && !tmp.equals("-") && !tmp.equals("*") && !tmp.equals("/"))
s1 = tmp;
c = 2;
txt.setText("/");
}
});
bequal.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (s1 == "+" || s1 == "-" || s1 == "/" || s1 == "*") {
i = 0;
} else if (s1 == null || s1 == "" || s1.trim().length() == 0) {
i = i;
} else {
i = Integer.parseInt(s1);
}
s2 = (String) txt.getText();
if (s2 == "+" || s2 == "-" || s2 == "/" || s2 == "*") {
i1 = 0;
} else if (s2 == null || s2 == "" || s2.trim().length() == 0) {
i1 = 0;
} else {
i1 = Integer.parseInt(s2);
}
if (c == 0) {
i = i + i1;
} else if (c == 1) {
i = i - i1;
} else if (c == 2) {
if (i1 == 0) {
Toast.makeText(getApplicationContext(), "Invalid Input", Toast.LENGTH_LONG).show();
i = 0;
} else {
i = i / i1;
}
} else if (c == 3) {
i = i * i1;
} else {
i = 0;
}
txt.setText(i + "");
}
});
bclear.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
s = (String) txt.getText();
if (s.equals("+") || s.equals("-") || s.equals("/") || s.equals("*") || s.equals("")) {
i = 0;
} else {
i = Integer.parseInt(s);
i = i / 10;
}
if (i == 0) {
txt.setText("");
} else {
txt.setText(i + "");
}
s = null;
}
});
bce.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
txt.setText("");
i = 0;
i1 = 0;
s1 = "";
s2 = "";
c = -1;
}
});
}
#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;
}
#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);
}
}