Question

我正在尝试根据3个Spinner中当前选定的选项填充TextView，但似乎无法弄清楚如何从Spinners中检索所选值以调用更新函数。这是我目前的代码（非常混乱，但我只是学习Java :)），

public class AgeFun extends Activity {
private String[] dayNames;
private String[] yearArray;
private final static int START_YEAR = 1990;
private static TextView textDisp;
private Button calcButton; 
private static Spinner spinnerDay, spinnerYear, spinnerMonth;
private static ArrayAdapter<?> monthAdapter, dayAdapter, yearAdapter;
private int year, month, day;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    year = 2000;
    month = 1;
    day = 1;
    textDisp = (TextView) findViewById(R.id.textView1);
    calcButton = (Button) findViewById(R.id.button);
    calcButton.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            // Perform action on clicks
            AgeFun.updateAge(year, month, day);
        }
    });

    // Month spinner
    spinnerMonth = (Spinner) findViewById(R.id.spinnerFirst);
    monthAdapter = ArrayAdapter.createFromResource(
            this, R.array.monthList, android.R.layout.simple_spinner_item);
    monthAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerMonth.setAdapter(monthAdapter);

    // Day spinner
    dayNames = new String[31];
    for(int i =1; i <= 31; ++i)
    {
        dayNames[i-1] = Integer.toString(i);
    }
    spinnerDay = (Spinner) findViewById(R.id.spinnerSecond);
    dayAdapter = new ArrayAdapter<CharSequence>(this, android.R.layout.simple_spinner_item, dayNames);
    spinnerDay.setAdapter(dayAdapter);

    // Year spinner
    yearArray = new String[40];
    for(int i =0; i < 40; ++i)
    {
        yearArray[i] = Integer.toString(START_YEAR+i);
    }
    spinnerYear = (Spinner) findViewById(R.id.spinnerThird);
    yearAdapter = new ArrayAdapter<CharSequence>(this, android.R.layout.simple_spinner_item, yearArray);
    spinnerYear.setAdapter(yearAdapter);

    updateAge(2000,1,1);
}

private static void updateAge(int year, int month, int day) {
    Date dob = new GregorianCalendar(year, month, day).getTime();
    Date currDate = new Date();

    long age = (currDate.getTime() - dob.getTime()) / (1000 * 60 * 60 * 24) / 365;
    textDisp.setText("Your are " + Long.toString(age) + " years old");
}

}

任何帮助都会很棒。

TIA

Answer 1

可能此代码有帮助（您使用位置或ID来定位适配器中的项目）

spnCountries.setOnItemSelectedListener(spnCountriesListener);


private Spinner.OnItemSelectedListener spnCountriesListener =

  new Spinner.OnItemSelectedListener() {

    public void onItemSelected(AdapterView parent, View v, int position, long id) {

      Log.i("print", parent.getSelectedItem().toString());

    }



    public void onNothingSelected(AdapterView parent) { }              

};

Answer 2

您可以使用getSelectedItem获取当前微调器值。由于您使用CharSequence填充了数组适配器，因此这是所选项目的类型。

或者，您应该能够使用ArrayAdapter并直接处理整数。我相信微调器使用了它提供的对象类型的toString方法。

编辑：我错过了重要部分，为每个微调器添加一个onItemSelected侦听器，即：

    AdapterView.OnItemSelectedListener listener = new AdapterView.OnItemSelectedListener () {
        onItemSelected(AdapterView<?> parent, View view, int position, long id) {
           updateAge();
        }
    }
    dayAdapter.setOnItemSelectedListener(listener);
    ....

   private void updateAge() {
      int day = spinnerDay.getSelectedItem();
      ....
   }

如何更新Button上的TextView单击Spinner（s）值

2 个答案: