I'm trying to teach myself how to write android apps and I'm having trouble registering a button click and taking actions based on which radio button is selected at the time. This is a simple tip calculator:
import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.TextView;
import android.widget.RadioGroup;
import android.view.View;
public class TipCalc extends Activity implements RadioGroup.OnCheckedChangeListener,View.OnClickListener
{
TextView result;
RadioGroup radiogroup1;
RadioButton r1,r2,r3;
Button calculate;
EditText bill, resulttotal;
private int radioCheckedId = -1;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
radiogroup1 = (RadioGroup) findViewById(R.id.radiogroup1);
Button calculate = (Button) findViewById(R.id.calculate);
RadioButton r1 = (RadioButton) findViewById(R.id.poor);
RadioButton r2 = (RadioButton) findViewById(R.id.average);
RadioButton r3 = (RadioButton) findViewById(R.id.excellent);
EditText bill = new EditText(this);
EditText resulttotal = new EditText(this);
radiogroup1.setOnCheckedChangeListener(this);
calculate.setOnClickListener(this);
//bill.setText("0");
//resulttotal.setText("0");
}
public void onCheckedChanged(RadioGroup group, int checkedId) {
radioCheckedId = checkedId;
}
public void onClick(View v)
{
if (v == calculate)
{
String billtotal;
double total = 0;
billtotal = bill.getText().toString();
final int aInt = Integer.parseInt(billtotal);
if (radioCheckedId == 1)
{
total = aInt * 1.1;
final String aString = Double.toString(total);
resulttotal.setText(aString);
}
if (radioCheckedId == 2)
{
total = aInt * 1.15;
final String aString = Double.toString(total);
resulttotal.setText(aString);
}
if (radioCheckedId == 3)
{
total = aInt * 1.2;
final String aString = Double.toString(total);
resulttotal.setText(aString);
}
}
}
}
Everything loads just fine, but nothing happens when I press the calculate button in the virtual phone.
The problem is where you're comparing the RadioGroup's selected id... you'll want to change your onClick() to:
public void onClick(View v) {
if (v == calculate) {
String billtotal;
double total = 0;
billtotal = bill.getText().toString();
final int aInt = Integer.parseInt(billtotal);
if (radioCheckedId == R.id.poor) {
total = aInt * 1.1;
final String aString = Double.toString(total);
resulttotal.setText(aString);
}
if (radioCheckedId == R.id.average) {
total = aInt * 1.15;
final String aString = Double.toString(total);
resulttotal.setText(aString);
}
if (radioCheckedId == R.id.excellent) {
total = aInt * 1.2;
final String aString = Double.toString(total);
resulttotal.setText(aString);
}
}
}
onCheckedChanged() gives you will be the R.id for the view and not just a number which tells you which it is in sequence.
A few quick (unrelated) suggestions:
The above suggestions would look something like:
public void onClick(View v) {
if (v.getId() == R.id.calculate) {
String billtotal;
double total = 0;
billtotal = bill.getText().toString();
final int aInt = Integer.parseInt(billtotal);
switch(radioCheckedId) {
case R.id.poor:
total = aInt * 1.1;
final String aString = Double.toString(total);
resulttotal.setText(aString);
break;
case R.id.average:
total = aInt * 1.15;
final String aString = Double.toString(total);
resulttotal.setText(aString);
break;
case R.id.excellent:
total = aInt * 1.2;
final String aString = Double.toString(total);
resulttotal.setText(aString);
break;
default:
// do something for when nothing is selected... maybe throw an error?
break;
}
}
}
Lastly, if all you're doing in onCheckedChanged() is storing the value you could get rid of it all together and just check for it in the onClick(). Something like:
public void onClick(View v) {
int radioCheckedId = radiogroup1.getCheckedRadioButtonId();
if (v == calculate) {
// ...
Unrelated, but another problem I noticed (and someone else mentioned)... if your EditTexts are listed in the XML layout then you'd need to get hooks to them like this (and not create new ones):
EditText bill = (EditText) findViewById(R.id.bill );
EditText resulttotal = (EditText) findViewById(R.id.resulttotal);
Also, you could probably just use a TextView instead of an EditView for the result if yo udon't need it to be editable.
import java.text.NumberFormat;
import java.util.Locale;
import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.TextView;
import android.widget.RadioGroup;
import android.view.View;
public class TipCalc extends Activity
{
TextView result;
RadioGroup radiogroup1;
RadioButton r1,r2,r3;
Button calculate;
EditText bill, resulttotal;
Locale currentLocale = Locale.getDefault();
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
radiogroup1 = (RadioGroup) findViewById(R.id.radiogroup1);
final Button calculate = (Button) findViewById(R.id.calculate);
final RadioButton r1 = (RadioButton) findViewById(R.id.poor);
final RadioButton r2 = (RadioButton) findViewById(R.id.average);
final RadioButton r3 = (RadioButton) findViewById(R.id.excellent);
final EditText bill = (EditText) findViewById(R.id.bill);
final EditText tiptotal = (EditText) findViewById(R.id.tiptotal);
final EditText resulttotal = (EditText) findViewById(R.id.resulttotal);
bill.setText("0.00");
tiptotal.setText("0.00");
resulttotal.setText("0.00");
calculate.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) throws NumberFormatException {
if (v == calculate)
{
NumberFormat currencyFormatter;
currencyFormatter = NumberFormat.getCurrencyInstance(currentLocale);
double atotal = 0;
double btotal = 0;
String billtotal = bill.getText().toString();
Double aDbl = 0.00;
try
{
aDbl = Double.parseDouble(billtotal);
}
catch(NumberFormatException n)
{
aDbl = 0.00;
}
if (r1.isChecked())
{
atotal = aDbl * 1.1;
btotal = aDbl * 0.1;
}
if (r2.isChecked())
{
atotal = aDbl * 1.15;
btotal = aDbl * 0.15;
}
if (r3.isChecked())
{
atotal = aDbl * 1.2;
btotal = aDbl * 0.2;
}
final String bString = currencyFormatter.format(btotal);
tiptotal.setText(bString);
final String aString = currencyFormatter.format(atotal);
resulttotal.setText(aString);
}
}
});
}
}
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