将setOnFocusChangeListener设置为EditText时Android应用程序崩溃
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,我logcat向我发送java.lang.nullPointerException..为什么将setOnFocusChangeListener设置为EditText时Android应用程序崩溃,android,Android,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,我logcat向我发送java.lang.nullPointerException..为什么 public class MainActivity extends FragmentActivity implements HeadlinesFragment.OnHeadlineSelectedListener { private int myYear, myMonth, myD
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);
}
});
确保您的版面
news\u articles.xml
中包含editText2
如果在第
txt1.setOnFocusChangeListener
行上获得NullPointerException
,这可能是崩溃后显示堆栈跟踪的原因