Question

After being pointed in the right direction to learn about views and layouts I was able to make a calculator that I thought looked pretty nice. I added some very basic code to it that is far from elegant but i wanted to get my feat wet with making a simple app. So far it only says the process has stopped and to try again. I am 100 percent positive that it is my code and not my ui making this happen. I was able to make a basic button counter before with 1 button but now with 15 buttons I think I screwed up.

Here is the code for the calculator called hellocats(i was following a basic tutorial and kept on adding)

package com.hellocats;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.*;
public class hellokatz extends Activity {
    /** Called when the activity is first created. */



int numbermover = 0;
int[] numbers ={0,0};

String sign = "+";
int answer;




@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

   final Button button0 = (Button)findViewById(R.id.button0);
   final Button button1 = (Button)findViewById(R.id.button1);
   final Button button2 = (Button)findViewById(R.id.button2);
   final Button button3 = (Button)findViewById(R.id.button3);
   final Button button4 = (Button)findViewById(R.id.button4);
   final Button button5 = (Button)findViewById(R.id.button5);
   final Button button6 = (Button)findViewById(R.id.button6);
   final Button button7 = (Button)findViewById(R.id.button7);
   final Button button8 = (Button)findViewById(R.id.button8);
   final Button button9 = (Button)findViewById(R.id.button9);

   final Button addbutton = (Button)findViewById(R.id.buttonadd);
   final Button subbutton = (Button)findViewById(R.id.buttonsub);
   final Button mulbutton = (Button)findViewById(R.id.buttonmul);
   final Button divbutton = (Button)findViewById(R.id.buttondiv);
   final Button equalsbutton = (Button)findViewById(R.id.buttonequals);

   final  EditText num1 = (EditText)findViewById(R.id.num1);
   final EditText mysign = (EditText)findViewById(R.id.sign);
   final  EditText num2 = (EditText)findViewById(R.id.num2);
   final  EditText answer = (EditText)findViewById(R.id.answer);


    num1.setText(numbers[0]);
    num2.setText(numbers[1]);
    mysign.setText(sign);


    button0.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 0;

        }
    });
       button1.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 1;

        }
    });
       button2.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 2;

        }
    });
       button3.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 3;

        }
    });
       button4.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 4;

        }
    });
       button5.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 5;

        }
    });
       button6.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 6;

        }
    });
       button7.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 7;

        }
    });
       button8.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 8;

        }
    });
       button9.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            numbers[numbermover] = 9;

        }
       });


}
}

Here is the layout file main.xml

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:orientation="vertical">
    <TableRow android:id="@+id/tableRow1" android:layout_height="wrap_content" android:layout_width="match_parent">
        <Button android:text="  1   " android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  2   " android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  3   " android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  4   " android:id="@+id/button4" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  5   " android:id="@+id/button5" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  6   " android:id="@+id/button6" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  7   " android:id="@+id/button7" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
    </TableRow>
    <TableRow android:id="@+id/tableRow2" android:layout_height="wrap_content" android:layout_width="match_parent">
        <Button android:text="  8   " android:id="@+id/button8" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  9   " android:id="@+id/button9" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  0   " android:id="@+id/button0" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
    </TableRow>
    <TableRow android:id="@+id/tableRow3" android:layout_height="wrap_content" android:layout_width="match_parent">
        <Button android:text="  +   " android:id="@+id/buttonadd" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  -   " android:id="@+id/buttonsub" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  X   " android:id="@+id/buttonmul" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  /   " android:id="@+id/buttondiv" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="  =   " android:id="@+id/buttonequals" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
    </TableRow>
    <TableRow android:id="@+id/tableRow4" android:layout_height="wrap_content" android:layout_width="match_parent">
        <EditText android:text="      " android:id="@+id/num1" android:layout_width="wrap_content" android:layout_height="wrap_content"></EditText>
        <EditText android:text="      " android:id="@+id/sign" android:layout_width="wrap_content" android:layout_height="wrap_content"></EditText>
        <EditText android:text="      " android:id="@+id/num2" android:layout_width="wrap_content" android:layout_height="wrap_content"></EditText>
        <EditText android:text="  =   " android:id="@+id/equals" android:layout_width="wrap_content" android:layout_height="wrap_content"></EditText>
        <EditText android:text="      " android:id="@+id/answer" android:layout_width="wrap_content" android:layout_height="wrap_content"></EditText>
    </TableRow>
</LinearLayout>  

What did I do incorrectly in my java file and how can I fix it and learn from it?

Thank you:Aslo i am very new to your website and so far cannot figure out for the life of me how to post the main.xml file. I tried CTRL+K and CTRL+V to past it in and so far nothing

Answer 1

Your array int[] numbers ={0,0}; is of type int.

EditText accepts a CharSequence so my guess is that it throws an error at the line below:

num1.setText(numbers[0]);

Try something like (if it works, update then num2 and mysign):

num1.setText(Integer.toString(numbers[0]));

As GrAnd pointed out, setText also accepts an int that represents a resourceId. It couldnt find the string with id 0 and threw the error.