Android Studio在编辑文本中的parseint时抛出空指针异常

Question

它接触像抛出异常的部分是onclick listerner之后的部分，因为如果我评论它应用程序将运行良好（虽然不起作用）

public class MyActivity extends Activity {

    int poundtwenty;
    int poundten;
    int poundfive;
    int poundtwo;
    int poundone;
    int tenpences;
    int twentypences;
    int fiftypences;
    int £20out;
    int £10out;
    int £5out;
    int £2out;
    int £1out;
    double fiftyout;
    double twentyout;
    double tenout;
    double Total;
    EditText in£20;
    EditText in£10;
    EditText in£5;
    EditText in£2;
    EditText in£1;
    EditText in50;
    EditText in20;
    EditText in10;
    Button Go;
    TextView outTotal;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);
        if (savedInstanceState == null) {
            getFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();

            in£20  = (EditText) findViewById(R.id.poundtwentyin);
            in£10 = (EditText) findViewById(R.id.poundtenin);
            in£5 = (EditText) findViewById(R.id.poundfivein);
            in£2 = (EditText) findViewById(R.id.poundtwoin);
            in£1 = (EditText) findViewById(R.id.poundonein);
            in50 = (EditText) findViewById(R.id.fiftyin);
            in20 = (EditText) findViewById(R.id.twentyin);
            in10 = (EditText) findViewById(R.id.tenin);
            Go = (Button) findViewById(R.id.go);
          Go.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
               int poundtwenty = Integer.parseInt(in£20.getText().toString());
                int poundten = Integer.parseInt(in£10.getText().toString());
                int poundfive = Integer.parseInt(in£5.getText().toString());
                int poundtwo = Integer.parseInt(in£2.getText().toString());
                int poundone = Integer.parseInt(in£1.getText().toString());
                int fiftypences = Integer.parseInt(in50.getText().toString());
                int twentypences = Integer.parseInt(in20.getText().toString());
                int tenpences = Integer.parseInt(in10.getText().toString());
                double fiftyout = (double) fiftypences/2;
                double twentyout = (double) twentypences/5;
                double tenout = (double) tenpences/10;
                double Total = (double) tenout + (double) twentyout + (double) fiftyout + (double) poundone
                        + (double) poundtwo*2 + (double) poundfive*5 + (double) poundten*10 + (double) poundtwenty*20;

                }
            });


        }
    }

任何帮助将不胜感激

stacktrace（无法在此处正确格式化） https://drive.google.com/file/d/0B-uBh91OVJUycXlFMFVFTUYwbjQ/edit?usp=sharing