当我将 OnFocusChangeListener 设置为 editText 时，我的应用程序不断崩溃。应用程序崩溃并且我 logcat 向我发送 java.lang.nullPointerException ..为什么？
public class MainActivity extends FragmentActivity
implements HeadlinesFragment.OnHeadlineSelectedListener {
private int myYear, myMonth, myDay;
static final int ID_DATEPICKER = 0;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.news_articles);
EditText txt1 = (EditText) findViewById(R.id.editText2);
txt1.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
final Calendar c = Calendar.getInstance();
myYear = c.get(Calendar.YEAR);
myMonth = c.get(Calendar.MONTH);
myDay = c.get(Calendar.DAY_OF_MONTH);
showDialog(ID_DATEPICKER);
}
});