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Operater '*' cannot be applied to 'android.widget.RadioButton', 'int'

Operater '*' cannot be applied to 'android.widget.RadioButton', 'int'
I'm creating an app that is for the cost of printing paper using radio buttons with a 20 paper limit.
I'm unsure as to why i'm getting this error as i'm grabbing getting the information from my EditText.
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.TextView;
import android.widget.Toast;
import java.text.DecimalFormat;
public class MainActivity extends Activity {
double totalcost;
double price1 = 0.15;
double price2 = 0.45;
double price3 = 0.80;
int prints;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setLogo(R.mipmap.ic_launcher);
getActionBar().setDisplayUseLogoEnabled(true);
final EditText prints =(EditText)findViewById(R.id.noprint);
final RadioButton price1 = (RadioButton)findViewById(R.id.rad1);
final RadioButton price2 = (RadioButton)findViewById(R.id.rad2);
final RadioButton price3 = (RadioButton)findViewById(R.id.rad3);
final TextView totalcost =(TextView)findViewById(R.id.cost);
Button calculate =(Button)findViewById(R.id.btn1);
calculate.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String prints = noprint.getText().toString();
int prints = Integer.parseInt(noprint);
DecimalFormat tenth = new DecimalFormat("$##.##");
if (price1.isChecked()) {
if (prints <= 20) {
totalcost = price1 * prints;
} else {
Toast.makeText(MainActivity.this, "Number of prints must be less than 20", Toast.LENGTH_LONG).show();
}
}

Looking at your program, you have a naming problem. On class-level, you define an attribute
double price1 = 0.15;
but within method onCreate(...) you also define
final RadioButton price1 = (RadioButton)findViewById(R.id.rad1);
which effectively hides the attribute. Thus, when you write
totalcost = price1 * prints;
You command java to multiply a RadioButton with an int. Since this binary operator (*(RadioButton, int)) is undefined in Java, you get the compiler error you got. Your intention is probably to use the attribute price1. A quick fix would be to expicitly use the attribute through the this reference:
totalcost = this.price1 * prints;
A cleaner fix would be to rename your variables so you do not hide the attribute with the local variable.

Value of 1 array equals the value of another in Android

I have two arrays :
String []myExpressions = {"20+10","50+50","25+25","10+15"};
String []answers = {"30#","100#","50#","25#"};
When the user clicks the generate button it generates an expression from the array myExpressions and displays it in text-field. Then I require the user to enter the answer using the buttons provided. The answer is displayed in a EditText. When the user enters an answer they should enter a #(like a submit button) and if is the correct answer it should display correct in a text-field. So if the position in the expression array is 1, the correct answer is in the answer array in the same position. How would i check if they are in the same position?
For example: myExpressions[1] correct answer to this is answers[1].
Here is my code:
package com.gamesup.braingame;
import java.util.Random;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class Easy extends Activity implements OnClickListener{
EditText display;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.easy);
display = (EditText)findViewById(R.id.displayText);
display.setText("?");
final String []myExpressions = {"20+10","50+50","25+25","10+15"};
final String []answers = {"30#","100#","50#","25#"};
final TextView displayExpression = (TextView) findViewById(R.id.expression);
Button generate = (Button) findViewById(R.id.random_gen);
generate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Random ranGenerate = new Random ();
int random = ranGenerate.nextInt(4) ;
displayExpression.setText(myExpressions[random]);
}
});
}
static boolean isEmpty = true;
public void num_Clicked(View v){
Button btn = (Button) findViewById(v.getId());
//getting the button object and using a view to get the id of the buttons
if (v.getId()== R.id.del_button){
String s = display.getText().toString();
s = s.substring(0, s.length() - 1);
display.setText(s);
return;
}
if(isEmpty){
display.setText(btn.getText());
isEmpty = false;
}
else{
display.append(btn.getText().toString());
// storing the existing number into editText and current text is set
//to current button value
//display.setText(number+btn.getText().toString());
//the total in the editText
}
if (v.getId()== R.id.hash_button){
String userAns = display.getText().toString();
}
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
}

For starters arrays in Java Begin at Index 0 so therefore , to compare the first items of the Array you should be using something like this to check if things are equal:
EditText myAnswer = (EditText) findViewById(R.id.myAnswer);
String answer = myAnswer.getText().toString();
// Notice my loop starts at 0 because the first index of an array is 0
for(int i = 0 ; i < answers.length; i++)
{
if(answers[i].equals(answer))
{
// Congratulate the User for getting it Right
}
}
It seems as though you have a little bit of a shaky logic. IMHO you should be using a multidimensional Array.
With a multidimensional Array you can essentially set up keys and values.
This is how I think your application should be configures
// This Array says , I am an array that holds arrays
String [][] multiArray = {{"4 + 5", "9"},
{"20 * 3","60"},
{"99 - 9","90"}};
// Fetch your random question, since we know our questions are the first item in out Array we can use the index [x][0] depending on the index you pull from
String question = multiArray[0][0];
// To do this randomly
Random ranGenerate = new Random ();
int random = ranGenerate.nextInt(4) ;
String question = multiArray[random][0];
// Get the Answer from yout EditText
String answer = myAnswer.getText().toString();
// Using a for loop iterate on the base index
for(int i = 0; i < multiArray.length ; i++)
{
// if the answer is in position 1 of Array [i]
if(answer.equals(mutliArray[i][1])
{
// We have found the answer, Congratulate the User
}else{
// Tell them how bad they are since they can't solve simple equations!
// ....joking obviously we would be nice and let them know its not the answer
}
}

In this line
int random = ranGenerate.nextInt(4) ;
why don't you make random an instance variable inside your class? This way you would preserve the index, and you would know which index to use to compare the answer.

Output not able to show at UI

I'm currently trying to write an app to calculate BMI and calories needed by a person (male / female).
My apps have 2 parts:
1. BMI calculation
2. Calories needed
The first part works well (so I excluded the code for this part), but for the 2nd part, calories needed calculation, it is not able to show up the result as expected (after I click on 'calories needed' button). Probably something is still missing but I cant find it so far.
Everything looks fine in the code, no error.
Can anyone help to have a look on it? :) thanks in advance.
Code as below:
package com.example.caloriescalculator;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.RadioButton;
public class BMIcalculation extends Activity
{
EditText weightE;
EditText heightE ;
EditText ageE ;
TextView caloriesresult ;
RadioButton male;
RadioButton female;
Button calories;
EditText weightText ;
EditText heightText ;
EditText ageText;
TextView resultText;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.bmilayout_main);
weightE = (EditText)findViewById(R.id.weightText);
heightE = (EditText)findViewById(R.id.heightText);
ageE = (EditText)findViewById(R.id.ageText);
caloriesresult = (TextView)findViewById(R.id.caloriesText);
male = (RadioButton) findViewById(R.id.maleradio);
female = (RadioButton) findViewById(R.id.femaleradio);
Button calories = (Button) findViewById(R.id.caloriesButton);
calories.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View arg0)
{
int caloriesneed = 0, weight = 0, height = 0, age = 0;
try {
if ((!weightE.equals("")) && (!heightE.equals("")) && (!ageE.equals("")))
{
weightE = (EditText) findViewById(R.id.weightText);
weight = Integer.parseInt(weightE.getText().toString().trim());
heightE = (EditText) findViewById(R.id.heightText);
height = Integer.parseInt(heightE.getText().toString().trim());
ageE = (EditText) findViewById(R.id.ageText);
age = Integer.parseInt(ageE.getText().toString().trim());
if (male.isSelected())
{
caloriesneed = (int) Math.round (655 + 9.6*weight + 1.8*height - 4.7*age);
caloriesresult.setText(caloriesneed);
}
else if (female.isSelected())
{
caloriesneed = (int) Math.round (66 + 13.7*weight + 5*height - 6.8*age);
caloriesresult.setText(caloriesneed);
}
}
}
catch (Exception k)
{ System.out.println(k);
}
}
});
}

caloriesresult.setText(caloriesneed);
This is problem. In Android if you assign pure int variable to some TextWidget, error will be thrown because Android will interpret it as resouce id of stored String in strings.xml.
So for this reason you need explicit casting. You can achieve it with concentation or an usage of String.valueOf(int value) or Integer.toString(int value) method:
textWidget.setText(Integer.toString(value)); // best approach
textWidget.setText(String.valueOf(value));
textWidget.setText("" + value);
Note: This is absolutely normal behaviour since if you are developing comercial application, usually you want to have support for more languages - and this feature requires localised Strings stored in proper XML file(s).

I guess it's because you try to input an integer to settext() which requires a string for input parameter, so you can try:
caloriesresult.setText("" + caloriesneed);
or
caloriesresult.setText(Integer.toString(caloriesneed));
or
caloriesresult.setText(String.valueOf(caloriesneed));

Android: Array of dynamically generated ImageButtons only returns info from last one created when clicked

I have an activity that generates and displays a GridLayout of custom ImageButtons called MapCells (It's a game map, surprise.) The MapCells are randomly generated and contain some variables that relate to terrain type as well as looking different (the image). What happens when I run my code is that I get my lovely random map, and when I click on the cells they should toast up their id on the screen (a diagnostic aid) as well as getting their stored variables and setText-ing them to some TextViews in the same activity. How it actually works when I click on the MapCells is that they toast the unique id (as expected) and have their unique appearances, but the terrain values that display are of the last MapCell that was generated in all cases. I thought this was the result of my 'for' loop creating all of the MapCells as the variable q (visible in commented out code) which I was just overwriting every loop, so I rewrote it to the code below, however, I am getting the same problem. Other questions I have looked at seemed to indicate that giving them the ids would solve this. Any ideas?
package com.<redacted>
import java.util.Random;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TableRow;
import android.widget.TextView;
import android.widget.Toast;
public class MapScreen extends Activity implements OnClickListener{
private static int dimen = 110; //the side length of map cells
private int currentFood;
private String currentName;
private MapCell[] storage = new MapCell[18];//keep the cells in here
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map_screen); //the xml
//It's Randy the randomizer!
Random randy = new Random();
//Generate 6 random MapCells per row for use in our map.
//MapCell q; -this is old and unused now
for(int i=0; i<=5; i++){
//q = new MapCell(randy.nextInt(4), this); //create and randomize
//q.setId(i); //issue identity
storage[i] = new MapCell(randy.nextInt(4), this); //shove it in the array
storage[i].setId(i);
storage[i].setOnClickListener((OnClickListener) this);
//q.setOnClickListener((OnClickListener) this);
((TableRow)findViewById(R.id.mapRow01)).addView(storage[i], dimen, dimen); //add cell to display
}
for(int j=0; j<=5; j++){
//q = new MapCell(randy.nextInt(4), this);
//q.setId(j+6);
//storage[q.getId()] = q; //shove it in the array
//q.setOnClickListener((OnClickListener) this);
storage[j+6] = new MapCell(randy.nextInt(4), this); //shove it in the array
storage[j+6].setId(j+6);
storage[j+6].setOnClickListener((OnClickListener) this);
((TableRow)findViewById(R.id.mapRow02)).addView(storage[j+6], dimen, dimen); //add cell to display
}
for(int k=0; k<=5; k++){
//q = new MapCell(randy.nextInt(4), this);
//q.setId(k+12);
//storage[q.getId()] = q; //shove it in the array
//q.setOnClickListener((OnClickListener) this);
storage[k+12] = new MapCell(randy.nextInt(4), this); //shove it in the array
storage[k+12].setId(k+12);
storage[k+12].setOnClickListener((OnClickListener) this);
((TableRow)findViewById(R.id.mapRow03)).addView(storage[k+12], dimen, dimen); //add cell to display
}
}
public void displayCell(MapCell view){
//get the cell name view and then set its text to be the name of the clicked cell
try{ //we need to try in case it feeds in a non-MapCell view
currentName = storage[view.getId()].getName();
((TextView)findViewById(R.id.mapDisplayName)).setText(currentName);
currentFood = storage[view.getId()].getFood();
((TextView)findViewById(R.id.mapDisplayFood)).setText(String.valueOf(currentFood));
Toast.makeText(this, "Cell " + String.valueOf(view.getId()), Toast.LENGTH_SHORT).show(); //diagnostic line
}
catch (Exception x){
//frowny time
Toast.makeText(this, "Something Broke on cell " + String.valueOf(view.getId()) + " :(", Toast.LENGTH_SHORT).show();
}
}
public void onClick(View v){//when we click a MapCell
displayCell((MapCell)v);// feed it in
}
}
That's the relevant class. I can show you MapCell if you ask, but it's just an ImageButton with a few added variables along for the ride with getters. These variables are set by switch case using the random integer provided in the constructor.

As I see nothing wrong with your code, I'll take a shot in the dark. In your MapCell class, is the variable that holds terrain values defined using the static modifier?

Android. to display contacts as list view

I want to display contacts in list view and add actions on all contacts , like on click on a particular contact it should display the phone number , mail id and delete of the particular contact...
import android.app.ListActivity;
import android.content.ContentResolver;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.view.Menu;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class CPDemo1 extends ListActivity {
#SuppressWarnings("unchecked")
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
String str[]= {"datta","vivek","Nagesh sir","shiv"};
String name;
ContentResolver cr = getContentResolver();
Cursor cursor = cr.query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
int nameIdx = cursor.getColumnIndexOrThrow(ContactsContract.Contacts.DISPLAY_NAME);
if (cursor.moveToFirst())
do {
int x = 0;
name = cursor.getString(nameIdx);
str[x]= name;
x++;
ArrayAdapter arr = new ArrayAdapter(this, android.R.layout.simple_list_item_1,str);
setListAdapter(arr);
} while(cursor.moveToNext());
}

The problem in your current code is create new adapter for every loop. Just move ArrayAdapter arr = new ArrayAdapter(this, android.R.layout.simple_list_item_1,str);
out of do while loop. And another issue, You work too much on UIThread (loop through cursor )so user will see a black screen or ANR if your numbers of contact is huge. Learn to use AsyncQueryHandler and CursorAdapter, it's all in my link and nikki's link
And why don't you have a look at default Contacts app in Android source code:
Below is my custom Contacts App.
https://github.com/android/platform_packages_apps_contacts

Just have a look at below link and try using this code for displaying contacts saved in android phone book into your application.
http://developer.android.com/resources/samples/ContactManager/index.html

Here is a little change to the code posted by you, it will solve your problem.
if (cursor.moveToFirst())
{
int x = 0;
do {
name = cursor.getString(nameIdx);
Log.d("CONTENT",name);
str[x]= name;
x++;
} while(cursor.moveToNext());
ArrayAdapter<String> arr = new ArrayAdapter<String>(
this, android.R.layout.simple_list_item_1,str);
setListAdapter(arr);