[Android Q&A, Help & Troubleshooting] willocks1718:
Here is my first app (a basic calculator app to add up the numbers of coins you have, then to tell you the total dollar amount it equals) that I have tried to create to get started programming in Android but I am getting an error which is causing the app to force close when I click the calculate button. Here is my .java file and main.xml file. If anyone can help me I would greatly appreciate it, I have learned programming in a few different languages but it just seems this more difficult to learn. Maybe is just eclipse, its just the sometimes i can save a file without any errors then when i open it back up the next day errors will show up then if i resave the file they go away sometimes. So any advice on maybe why i'm having troubles (unless its just eclipse is odd sometimes or something) would also be appreciated. I have created some fairly intricate VB and C++ programs but never had troubles creating a simple program like this one. Thanks in advance for anyone that can help me solve my problem.

package com.innovativesolutions.utilities.change;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import com.innovativesolutions.utilities.change.R;

public class ChangecounterActivity extends Activity
{
private EditText numpen;
private EditText numnic;
private EditText numdim;
private EditText numqua;
private EditText numdol;
private EditText numfdol;
private EditText nummisc;
private EditText answer;
private Button btncalculate;
private Button btnreset;
private double penny = 0;
private double nickel = 0;
private double dime=0;
private double quarter = 0;
private double dollar = 0;
private double fdollar = 0;
private double misc = 0;
private double tot = 0;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
initControls();
}
private void initControls()
{
numpen = (EditText)findViewById(R.id.numpen);
numnic = (EditText)findViewById(R.id.numnic);
numdim = (EditText)findViewById(R.id.numdim);
numqua = (EditText)findViewById(R.id.numqua);
numdol = (EditText)findViewById(R.id.numdol);
numfdol = (EditText)findViewById(R.id.numfdol);
nummisc = (EditText)findViewById(R.id.nummisc);
answer = (EditText)findViewById(R.id.answer);
btncalculate = (Button)findViewById(R.id.btncalculate);
btnreset = (Button)findViewById(R.id.btnreset);
btncalculate.setOnClickListener(new Button.OnClickListener() { public void onClick (View v){ calculate(); }});
btnreset.setOnClickListener(new Button.OnClickListener() { public void onClick (View v){ reset(); }});
}
private void calculate()
{
penny=Double.parseDouble(numpen.getText().toString());
nickel=Double.parseDouble(numnic.getText().toString());
dime=Double.parseDouble(numdim.getText().toString());
quarter=Double.parseDouble(numqua.getText().toString());
dollar=Double.parseDouble(numdol.getText().toString());
fdollar=Double.parseDouble(numfdol.getText().toString());
misc=Double.parseDouble(nummisc.getText().toString());

tot=penny*.01+nickel*.05+dime*.1+quarter*.25+dollar+fdollar*5+misc;

answer.setText(Double.toString(tot));

}
private void reset()
{
numpen.setText("");
numnic.setText("");
numdim.setText("");
numqua.setText("");
numdol.setText("");
numfdol.setText("");
nummisc.setText("");
}
}

**************Here is the start of my main.xml file*******************

<?xml version="1.0" encoding="utf-8"?>
<TableLayout

android:layout_width="fill_parent"
xmlns:android="(took the beginning of this out so i could post this without it thinking i was linking a site.....schemas.android.com/apk/res/android"
android:layout_height="wrap_content">
<TableRow android:id="@+id/tableRow1" android:layout_width="wrap_content" android:layout_height='80dp'>
<TextView android:layout_width="wrap_content" android:id="@+id/widget30" android:layout_height="wrap_content" android:text="Pennies"></TextView>
<EditText android:text="" android:textSize="18sp" android:id="@+id/numpen" android:layout_width="51px" android:layout_height="wrap_content"><requestFocus></requestFocus></EditText>
</TableRow>

<TableRow android:id="@+id/tableRow2" android:layout_width="wrap_content" android:layout_height='80dp'>
<TextView android:id="@+id/widget31" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Nickels"></TextView>
<EditText android:text="" android:textSize="18sp" android:id="@+id/numnic" android:layout_width="wrap_content" android:layout_height="wrap_content"><requestFocus></requestFocus></EditText>
</TableRow>

<TableRow android:id="@+id/tableRow3" android:layout_width="wrap_content" android:layout_height='80dp'>
<TextView android:id="@+id/widget32" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Dimes"></TextView>
<EditText android:text="" android:textSize="18sp" android:id="@+id/numdim" android:layout_width="wrap_content" android:layout_height="wrap_content"><requestFocus></requestFocus></EditText>
</TableRow>

<TableRow android:id="@+id/tableRow4" android:layout_width="wrap_content" android:layout_height='49dp'>
<TextView android:id="@+id/widget33" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Quarters"></TextView>
<EditText android:id="@+id/numqua" android:textSize="18sp" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=""><requestFocus></requestFocus></EditText>
</TableRow>

<TableRow android:id="@+id/tableRow5" android:layout_width="wrap_content" android:layout_height='49dp'>
<TextView android:id="@+id/widget34" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="1$"></TextView>
<EditText android:id="@+id/numdol" android:textSize="18sp" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=""><requestFocus></requestFocus></EditText>
</TableRow>

<TableRow android:id="@+id/tableRow6" android:layout_width="wrap_content" android:layout_height='49dp'>
<TextView android:id="@+id/widget35" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="5$"></TextView>
<EditText android:id="@+id/numfdol" android:textSize="18sp" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=""><requestFocus></requestFocus></EditText>
</TableRow>

<TableRow android:id="@+id/tableRow7" android:layout_width="wrap_content" android:layout_height='49dp'>
<TextView android:id="@+id/widget36" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Misc"></TextView>
<EditText android:id="@+id/nummisc" android:textSize="18sp" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=""><requestFocus></requestFocus></EditText>
</TableRow>

<TableRow android:id="@+id/tableRow8" android:layout_width="wrap_content" android:layout_height='49dp'>
<Button android:text="Reset" android:layout_height="wrap_content" android:id="@+id/btnreset" android:layout_width="100dp"></Button>
<Button android:text="Calculate" android:layout_width="100dp" android:layout_height="wrap_content" android:id="@+id/btncalculate"></Button>
</TableRow>

<TableRow android:id="@+id/tableRow9" android:layout_width="wrap_content" android:layout_height='49dp'>
<TextView android:id="@+id/widget37" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Total="></TextView>
<EditText android:id="@+id/answer" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="0.00"></EditText>
</TableRow>
</TableLayout>