小编ste*_*hen的帖子

嘿伙计们,我遇到了一个抛出nullPointerExpression的spiner的麻烦我确定我错过了一些愚蠢的东西？

谢谢你的帮助

这是我的代码:

public class main extends Activity {/**首次创建活动时调用.*/

public TextView strCurrency;
public TextView strCurrencyOUT;
Button butCalc;
private Spinner spinner; 
private static final String[] array = { "AUD", "CAD", "USD", "GBP",};

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


    strCurrency = (TextView) this.findViewById(R.id.txtCurrency);
    strCurrencyOUT = (TextView) this.findViewById(R.id.txtOUT);

    butCalc = (Button) this.findViewById(R.id.butCalc);
    butCalc.setOnClickListener(new Button.OnClickListener() { public void onClick (View v){ calculate(); }});

    Spinner spinner = (Spinner) findViewById(R.id.widget28);
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,   android.R.layout.simple_spinner_item, array);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);

public void calculate() {

    String   str …