private TextView info;
private EditText input;
private Button getInfo;
long answer;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getInfo = (Button) findViewById(R.id.button1);
getInfo.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
input = (EditText) findViewById(R.id.editText1);
String s2 = input.getText().toString();
long inputNumber = Integer.parseInt(s2);
for (int i = 0; i <= inputNumber; i++) {
answer = fibonacci(i);
}
input.setText(answer + "");
}
});
}
public static long fibonacci(long n) {
if (n == 0) {
return 0;
} else if (n == 1) {
return 1;
} else {
return fibonacci(n - 1) + fibonacci(n - 2);
}
}
I made a program which generates fibonacci series for the number I give input through edit text and display the output value in edittext .Issue is when I enter 30 it generates fibonacci series but when I enter 50 or 100 app does not respond and stops .
I think it is because you have a lot of calculation on UI thread.
Try calculate it in AssyncTask, for example.
Related
public class MainActivity extends AppCompatActivity {
Button startButton;
ArrayList<Integer> answers=new ArrayList<Integer>();
int LocationOfRightAnswer;
TextView resultTextView;
TextView pointText;
Button button1;
Button button2;
Button button3;
Button button4;
int score=0;
int numberofquestions = 0;
TextView sumText;
TextView timertext;
RelativeLayout game;
Button playAgain;
public void playAgain(View view) {
score = 0;
numberofquestions = 0 ;
timertext.setText("30s");
pointText.setText("0/0");
resultTextView.setText("");
playAgain.setVisibility(View.INVISIBLE);
generateQuestion();
new CountDownTimer(30100,1000) {
#Override
public void onTick(long millisUntilFinished) {
timertext.setText(String.valueOf(millisUntilFinished / 1000) + "s");
}
#Override
public void onFinish() {
playAgain.setVisibility(View.VISIBLE);
timertext.setText("0s");
resultTextView.setText("Your Score is " + Integer.toString(score) + "/" + Integer.toString(numberofquestions));
}
}.start();
}
public void generateQuestion() {
Random random = new Random();
int a = random.nextInt(21);
int b = random.nextInt(21);
char[] ops = {'+' , '-' ,'*', '/'};
int l = random.nextInt(3) ;
sumText.setText(Integer.toString(a) + "+" + Integer.toString(b) );
LocationOfRightAnswer = random.nextInt(4);
answers.clear();
int incorrectAnswer;
for (int i=0; i<4; i++) {
if (i == LocationOfRightAnswer) {
answers.add(a + b);
}else {
incorrectAnswer = random.nextInt(41);
while (incorrectAnswer == a + b) {
incorrectAnswer = random.nextInt(41);
}
answers.add(incorrectAnswer);
}
}
button1.setText(Integer.toString(answers.get(0)));
button2.setText(Integer.toString(answers.get(1)));
button3.setText(Integer.toString(answers.get(2)));
button4.setText(Integer.toString(answers.get(3)));
}
public void chooseAnswer(View view) {
if (view.getTag().toString().equals(Integer.toString(LocationOfRightAnswer))) {
score++;
resultTextView.setText("Correct");
} else {
resultTextView.setText("Wrong!");
}
numberofquestions++;
pointText.setText(Integer.toString(score) + "/" + Integer.toString(numberofquestions));
generateQuestion();
}
public void start (View view) {
startButton.setVisibility(View.INVISIBLE);
game.setVisibility(View.VISIBLE);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startButton =(Button) findViewById(R.id.startButton);
sumText = (TextView) findViewById(R.id.sumTextView);
button1 = (Button) findViewById(R.id.button1);
button2 = (Button) findViewById(R.id.button2);
button3 = (Button) findViewById(R.id.button3);
button4 = (Button) findViewById(R.id.button4);
resultTextView = (TextView) findViewById(R.id.resultTextView);
pointText = (TextView) findViewById(R.id.pointsTextView);
timertext = (TextView) findViewById(R.id.timerTextView);
playAgain = (Button) findViewById(R.id.playAgain);
game = (RelativeLayout) findViewById(R.id.gamelayout) ;
playAgain(findViewById(R.id.playAgain));
}
}
please help me to adjust my code so that I the app can use all operators instead of just addition. I have tried to do it but I have only managed to create the array list for the operators but I could not find a way to change the code to include all of the operators.
Try this:
ArrayList<Double> answers=new ArrayList<Double>();
public void generateQuestion() {
Random random = new Random();
int a = random.nextInt(21);
int b = random.nextInt(21);
char[] ops = {'+' , '-' ,'*', '/'};
int l = random.nextInt(3) ;
char op = ops[random.nextInt(4)];
double correctAns=0;
switch(op){
case '+' : correctAns = a+b;
break;
case '/' : correctAns = (double)a/b;
break;
case '*' : correctAns = a*b;
break;
case '-' : correctAns = a-b;
break;
}
sumText.setText(Integer.toString(a) + op + Integer.toString(b) );
LocationOfRightAnswer = random.nextInt(4);
answers.clear();
int incorrectAnswer;
for (int i=0; i<4; i++) {
if (i == LocationOfRightAnswer) {
answers.add(correctAns);
}else {
incorrectAnswer = random.nextInt(41);
while (incorrectAnswer != correctAns) {
incorrectAnswer = random.nextInt(41);
}
answers.add((double)incorrectAnswer);
}
}
button1.setText(Double.toString(answers.get(0)));
button2.setText(Double.toString(answers.get(1)));
button3.setText(Double.toString(answers.get(2)));
button4.setText(Double.toString(answers.get(3)));
}
change ArrayList<Integer> answers=new ArrayList<Integer>(); to ArrayList<Double> answers=new ArrayList<Double>(); (int/int can be a double)
create a double variable contains the right answer (int/int can be a double)
choose an operation randomly.
use switch to define what operation is needed on a and bin case that every operation selected.
set the text to Integer.toString(a) + op + Integer.toString(b) instead of Integer.toString(a) + "+" + Integer.toString(b)
swap a+b to correctAns
First of all, I'm new to Android Studio. I'm currently trying to make a BMI calculator app where the user has to enter their weight and height and select the unit of measurement used for both. A Toast message (R.string.toastError) should pop up upon clicking a button if: (1-2) the EditText fields for weight and height are empty and (3) if the value of HeightInput is less than or equal to zero; else, the calculation should proceed.
The whole math part worked fine when I tested it, but when I left the fields blank, the app just crashes. The Toast pops up though when HeightInput = 0, but not when the EditText field for Weight is left empty at the same time. I think it's the way I wrote the 'if' statement that's giving me a problem.
// if edit text is empty
if (editTextWeightInput.getText().toString().length() == 0 || editTextHeightInput.getText().toString().length() == 0 || HeightInput <= 0) {
Toast.makeText(getApplicationContext(), R.string.toastError, Toast.LENGTH_SHORT).show();
} else {
double finalheight = Math.pow((HeightInput * constantHeight), 2.00);
double BodyMassIndex = (WeightInput * constantWeight) / finalheight;
DecimalFormat BodyMassIndexFormat = new DecimalFormat("##.##");
TextView textViewResult = (TextView) findViewById(R.id.textViewBmiResult);
textViewResult.setText(BodyMassIndexFormat.format(BodyMassIndex));
}
Here's the whole code for reference:
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// weight units spinner
final Spinner spinWeightUnit = (Spinner) findViewById(R.id.spinnerWeightUnit);
spinWeightUnit.setOnItemSelectedListener(this);
ArrayAdapter <CharSequence> WeightList = ArrayAdapter.createFromResource(this, R.array.WeightUnits, android.R.layout.simple_spinner_item);
WeightList.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinWeightUnit.setAdapter(WeightList);
// height units spinner
final Spinner spinHeightUnit = (Spinner) findViewById(R.id.spinnerHeightUnit);
spinHeightUnit.setOnItemSelectedListener(this);
ArrayAdapter <CharSequence> HeightList = ArrayAdapter.createFromResource(this, R.array.HeightUnits, android.R.layout.simple_spinner_item);
HeightList.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinHeightUnit.setAdapter(HeightList);
// calculate button
Button buttonCalculate = (Button) findViewById(R.id.buttonCalculate);
buttonCalculate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// declaration
EditText editTextWeightInput = (EditText) findViewById(R.id.editTextWeightInput);
EditText editTextHeightInput = (EditText) findViewById(R.id.editTextHeightInput);
double WeightInput = Double.valueOf(editTextWeightInput.getText().toString());
double HeightInput = Double.valueOf(editTextHeightInput.getText().toString());
String finalWeightUnit = String.valueOf(spinWeightUnit.getSelectedItem());
String finalHeightUnit = String.valueOf(spinHeightUnit.getSelectedItem());
double constantWeight;
double constantHeight;
// weight conversion constant
if (finalWeightUnit.equals("kilograms")) {
constantWeight = 1.00;
} else {
constantWeight = 1 / 2.204623;
}
// height conversion constant
switch (finalHeightUnit) {
case "inches":
constantHeight = 0.0254;
break;
case "centimeters":
constantHeight = 0.01;
break;
case "feet":
constantHeight = 1 / 3.2808;
break;
default:
constantHeight = 1.00;
break;
}
// if edit text is empty
if (editTextWeightInput.getText().toString().length() == 0 || editTextHeightInput.getText().toString().length() == 0 || HeightInput <= 0) {
Toast.makeText(getApplicationContext(), R.string.toastError, Toast.LENGTH_SHORT).show();
} else {
double finalheight = Math.pow((HeightInput * constantHeight), 2.00);
double BodyMassIndex = (WeightInput * constantWeight) / finalheight;
DecimalFormat BodyMassIndexFormat = new DecimalFormat("##.##");
TextView textViewResult = (TextView) findViewById(R.id.textViewBmiResult);
textViewResult.setText(BodyMassIndexFormat.format(BodyMassIndex));
}
}
});
}
#Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
}
#Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
}
I'd appreciate any help! Thanks!
Try below in if statement
if (editTextWeightInput.getText().toString().trim().isEmpty() || editTextHeightInput.getText().toString().trim().isEmpty() || HeightInput <= 0)
When you leave an EditText Empty the getString() function returns a null value. First you need to check for null in the if condition.
if (editTextWeightInput.getText() == null || editTextWeightInput.getText().toString().length() == 0 || HeightInput <= 0)
You need to validate your declaration code also.
// declaration
EditText editTextWeightInput = (EditText) findViewById(R.id.editTextWeightInput);
EditText editTextHeightInput = (EditText) findViewById(R.id.editTextHeightInput);
if(TextUtil.isEmpty(editTextWeightInput.getText().toString())||TextUtil.isEmpty(editTextHeightInput.getText().toString())){
Toast.makeText(getApplicationContext(), R.string.toastError,
Toast.LENGTH_SHORT).show();
}else{
double WeightInput = Double.valueOf(editTextWeightInput.getText().toString());
double HeightInput = Double.valueOf(editTextHeightInput.getText().toString());
String finalWeightUnit = String.valueOf(spinWeightUnit.getSelectedItem());
String finalHeightUnit = String.valueOf(spinHeightUnit.getSelectedItem());
double constantWeight;
double constantHeight;
}
I just learned Java using Android Studio.
My code error for use integer to count sum.
I try to decode string to integer but still error.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
edtvalue = (EditText) findViewById(R.id.value);
final Spinner edtjw = (Spinner) findViewById(R.id.spinner1);
txtpa = (TextView) findViewById(R.id.pa);
txttotal = (TextView) findViewById(R.id.total);
btncount.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String value = edtvalue.getText().toString().trim();
String jw = edtjw.getSelectedItem().toString().trim();
double h = Double.parseDouble(value);
double j = Double.parseDouble(jw);
String numbertostring = String.format ("%.2f", (0.02*h));
String numbertostring2 = String.format ("%.2f", (0.025*h));
String numbertostring3 = String.format ("%.2f", (0.0275*h));
if (j == 1){
txtpa.setText(numbertostring);
} else if (j ==2){
txtpa.setText(numbertostring);
} else if (j ==3){
txtpa.setText(numbertostring);
} else if (j ==4){
txtpa.setText(numbertostring2);
} else if (j ==5){
txtpa.setText(numbertostring3);
} else {
txtpa.setText(0);
}
int tot = (h*j)+txtpa;
txttotal.setText("Total : " + tot);
}}
By looking at the code snippet, you should get string value from txtpa which is of type TextView, then parse it into double
double tot = (h*j)+Double.parseDouble(txtpa.getText().toString());
as mentioned in the above comment by Naitik Soni.
I am new to programming and started android few week back.
public class MainActivity extends AppCompatActivity {
int a,i,j,k;
/*char [][] s1= new char[][]
{
{'A','B','C','D'},
{'E','F','G','H'},
{'I','J','K','L'},
{'M','N','O','P'},
{'Q','R','S','T'},
{'U','V','W','X'},
{' ','Y','Z',' '}};*/
char [][] s2=new char[8][8];
char[][] s3=new char[8][8];
int[] getlist= new int[10];;
char choice,choice1;
int x,b,c,d;
String[] messageText = new String[10];
String[] messageEdit = new String[10];
public void letterNo(View view) { // Method to show screen for getting number of letters
setContentView(R.layout.displaylettersno);
}
public void getNumber(View view) { // Method to get Numbers of Letter
EditText et = (EditText) findViewById(R.id.editText);
String s = et.getText().toString();
x = Integer.parseInt(s);
if (x > 0 && x < 9) {
et.setText("");
} else {
Toast.makeText(getApplicationContext(), "Wrong Entery... Enter again", Toast.LENGTH_LONG).show();
}
setContentView(R.layout.gettingcolumnno);
// Toast.makeText(getApplicationContext(),"Click on Column No in Which 1st Letter Appear",Toast.LENGTH_LONG).show();
TextView textView = (TextView) findViewById(R.id.textView8);
for (i = 0; i < x; i++){
textView.setText("Enter Column No. in which Your letters of name is
present:" );
}
}
public void buttondone(View view) {
EditText op = (EditText) findViewById(R.id.operator2);
String num = op.getText().toString();
for (i = 0; i < x; i++)
{
getlist[i] = Integer.parseInt(String.valueOf(op.getText()));
}
Toast.makeText(getApplicationContext(), "Inserted", Toast.LENGTH_LONG).show();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
I want to develop a Name guess game
1- it will ask user to enter the no. of letters he thought
2- it will ask user to enter the column no in which his letter present ( i want this to run according to user enter the no of letter .
suppose user enter 4 digits and it will ask to enter the column no 4 times.
and similarly it has a edit box where user enter column no .
i am using for loop for this purpose but it only show 1 time i am stuck here for 1 week . help me if you understand what i am trying to do . following is my code
Done button has to be pressed number of letters time to get columns.
TextView textView = (TextView) findViewById(R.id.textView8);
int numberOfColumnsEntered = 0;
public void getNumber(View view) {
// get number logic then
textView.setText("Enter Column No. "+(numberOfColumnsEntered+1)+" in which your letters appear");
}
public void buttondone(View view) {
EditText op = (EditText) findViewById(R.id.operator2);
String num = op.getText().toString();
getlist[numberofColumnsEntered] = Integer.parseInt(num);
numberofColumnsEntered++;
textView.setText("Enter Column No. "+(numberOfColumnsEntered+1)+" in which your letters appear");
if(numberofColumnsEntered == x) {
Toast.makeText(getApplicationContext(), "Inserted", Toast.LENGTH_LONG).show();
}
}
I made a program that computes the geometric mean and my program is already working but i have some sort of errors. Whenever i click the btnCalculate with an empty input in my inputValues my program stops working. how am I going to deal with this error? Thanks:)
final AutoCompleteTextView inputValues = (AutoCompleteTextView) findViewById(R.id.txt_input);
final TextView txtTotalNum = (TextView) findViewById(R.id.txt_totalNumber);
final TextView GeoMean= (TextView) findViewById(R.id.txt_GeoMean);
Button btnCalculate = (Button) findViewById(R.id.btncalculate);
btnCalculate.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View agr0) {
String []values = ( inputValues.getText().toString().split(","));//this is the inputed values in the editText using split method
txtTotalNum.setText(Integer.toString(values.length));//calculate the number of inputs
double[] convertedValues = new double[values.length];
double product1 =1.0;
double product=1.0;
for(int a = 0; a < convertedValues.length; a++){
convertedValues[a] =Integer.parseInt(values[a]);
//product *=convertedValues[a];
}
double geoMean = Math.pow(product, product1/convertedValues.length);
GeoMean.setText(Double.toString(geoMean));
}
});
Button btnclear = (Button)findViewById(R.id.btnclear);
btnclear.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
inputValues.setText("");
txtTotalNum.setText("");
GeoMean.setText("");
}
You are getting errors because your code is trying to split on empty strings or null and then accessing values[] that really have no index at all. Just check if the string fetched by the EditText has a length>0.
#Override
public void onClick(View agr0) {
String fetchedValues = ( inputValues.getText().toString());
if(fetchedValues.length>0)
{
String []values = fetchedValues.split(",");
txtTotalNum.setText(Integer.toString(values.length));//calculate the number of inputs
double[] convertedValues = new double[values.length];
double product1 =1.0;
double product=1.0;
for(int a = 0; a < convertedValues.length; a++){
convertedValues[a] =Integer.parseInt(values[a]);
//product *=convertedValues[a];
}
double geoMean = Math.pow(product, product1/convertedValues.length);
GeoMean.setText(Double.toString(geoMean));
}
else
{
//alert the user that the field is empty
}
}
#Override
public void onClick(View agr0) {
String []values = ( inputValues.getText().toString().split(","));//this is the inputed values in the editText using split method
if(values !=NULL){
txtTotalNum.setText(Integer.toString(values.length));//calculate the number of inputs
double[] convertedValues = new double[values.length];
double product1 =1.0;
double product=1.0;
for(int a = 0; a < convertedValues.length; a++){
convertedValues[a] =Integer.parseInt(values[a]);
//product *=convertedValues[a];
}
double geoMean = Math.pow(product, product1/convertedValues.length);
GeoMean.setText(Double.toString(geoMean));
}
}
// try this
btnCalculate.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View agr0) {
if(inputValues.getText().toString().length()>0){
String []values = ( inputValues.getText().toString().split(","));//this is the inputed values in the editText using split method
txtTotalNum.setText(Integer.toString(values.length));//calculate the number of inputs
double[] convertedValues = new double[values.length];
double product1 =1.0;
double product=1.0;
for(int a = 0; a < convertedValues.length; a++){
convertedValues[a] =Integer.parseInt(values[a]);
//product *=convertedValues[a];
}
double geoMean = Math.pow(product, product1/convertedValues.length);
GeoMean.setText(Double.toString(geoMean));
}
}
});
Your program stops at
convertedValues[a] =Integer.parseInt(values[a]);
because for an empty input the split array has no values, so its length is 0. And when you try to access values[0]you get an ArrayIndexOutOfBoundsException.
Just check if the input is emty, before splitting it.
if(!inputValues.getText().toString().equals("")){
... // do your stuff
} else {
// show a message
}