我正在尝试使用Appointment个对象的集合填充listview'Diary'。打开活动时，我收到运行时异常：java.util.NoSuchElementException。我一直绞尽脑汁想弄清楚这可能会发生什么，但由于我的机器人经验相当有限，我完全被难倒......
我的活动代码在这里：
DiaryAdapter dAdapter;
DateTime currentDate;
ListView diary;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Show the Up button in the action bar.
setupActionBar();
setContentView(R.layout.activity_diary);
diary = (ListView) findViewById(R.id.lstAppts);
currentDate = new DateTime();
populateDiaryNew(currentDate);
}
private void populateDiaryNew(DateTime dt) {
currentDate = dt;
ArrayList<Appointment> appointments = new ArrayList<Appointment>();
Cursor cursor = Db.Functions.getAppointmentList(dt);
if (cursor == null)
return;
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
Appointment appt = Db.Functions.getAppointment(cursor.getString(cursor.getColumnIndex("_id")));
appointments.add(appt);
cursor.moveToNext();
}
cursor.close();
ListIterator<Appointment> iter = appointments.listIterator();
DateTime lastEndTime = new DateTime();
int count = 0;
while (iter.hasNext()){
lastEndTime = iter.next().endDateTime;
if (count > 0)
{
if (iter.next().startDateTime.isAfter(lastEndTime))
{
Appointment freeAppt = new Appointment();
freeAppt.isFreeTime = true;
freeAppt.subject = "Free slot";
freeAppt.startDateTime = lastEndTime;
freeAppt.endDateTime = iter.next().startDateTime;
appointments.add(freeAppt);
}
}
count++;
}
DiaryAdapter adapter = new DiaryAdapter(this, R.layout.appointment_info, appointments);
//ArrayAdapter<Appointment> arrayAdapter = new ArrayAdapter<Appointment>(this, R.layout.appointment_info, R.id.lblSubject, appointments);
diary.setAdapter(adapter);
}
我的自定义适配器代码（DiaryAdapter）如下：
public class DiaryAdapter extends ArrayAdapter {
ArrayList<Appointment> appointments;
public DiaryAdapter(Context context, int resource, ArrayList<Appointment> appts) {
super(context, resource, appts);
this.appointments = appts;
}
static class ViewHolder {
TextView v1;
TextView v2;
TextView v3;
TextView v4;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
final Appointment temp = getItem(position);
ViewHolder viewHolder;
if (convertView == null) { //inflate convertView and populate viewHolder
viewHolder = new ViewHolder();
convertView = LayoutInflater.from(getContext()).inflate(R.layout.appointment_info, parent, false);
viewHolder.v1= (TextView) convertView.findViewById(R.id.lblTime);
viewHolder.v2= (TextView) convertView.findViewById(R.id.lblSubject);
viewHolder.v3= (TextView) convertView.findViewById(R.id.lblLocation);
viewHolder.v4= (TextView) convertView.findViewById(R.id.lblCustomer);
convertView.setTag(viewHolder); //set the tag
}
else {
viewHolder = (ViewHolder) convertView.getTag(); //re-use the ViewHolder to save calls to findViewById
}
viewHolder.v1.setText(temp.startDateTime.toString("hh:mm"));
viewHolder.v2.setText(temp.subject);
viewHolder.v3.setText(Db.Functions.getLocation(temp.locationId.toString()));
viewHolder.v4.setText(Db.Functions.getCustomerName(temp.customerId.toString()));
return convertView;
}
@Override
public Appointment getItem(int position) {
return appointments.get(position);
}
}
列表项的XML布局：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/lblTime"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignBaseline="@+id/lblSubject"
android:layout_alignBottom="@+id/lblSubject"
android:paddingTop="16dp"
android:paddingLeft="16dp"
android:text="Time"
android:textSize="16dp"
android:textColor="#FFFFFF" />
<TextView
android:id="@+id/lblSubject"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="Subject"
android:textSize="20dp"
android:paddingTop="16dp"
android:paddingRight="16dp"
android:textColor="#FFFFFF" />
<TextView
android:id="@+id/lblLocation"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/lblCustomer"
android:layout_alignBottom="@+id/lblCustomer"
android:layout_alignParentLeft="true"
android:text="Location"
android:paddingBottom="15dp"
android:paddingLeft="16dp"
android:textColor="#FFFFFF"
android:textSize="16dp" />
<TextView
android:id="@+id/lblCustomer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_below="@id/lblSubject"
android:text="Customer"
android:paddingBottom="15dp"
android:paddingRight="16dp"
android:textSize="16dp"
android:textColor="#FFFFFF" />
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_alignParentRight="true"
android:layout_below="@+id/lblLocation"
android:background="#333333" />
</RelativeLayout>
最后这是我的logcat异常：
08-30 16:13:29.268: E/AndroidRuntime(9917): FATAL EXCEPTION: main
08-30 16:13:29.268: E/AndroidRuntime(9917): java.lang.RuntimeException: Unable to start
activity ComponentInfo{com.example.myapp/com.example.myapp.DiaryActivity}:
java.util.NoSuchElementException
08-30 16:13:29.268: E/AndroidRuntime(9917): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
08-30 16:13:29.268: E/AndroidRuntime(9917): at
android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
08-30 16:13:29.268: E/AndroidRuntime(9917): at android.app.ActivityThread.access$700
(ActivityThread.java:140)
08-30 16:13:29.268: E/AndroidRuntime(9917): at android.app.ActivityThread
$H.handleMessage(ActivityThread.java:1237)
08-30 16:13:29.268: E/AndroidRuntime(9917): at android.os.Handler.dispatchMessage
(Handler.java:99)
08-30 16:13:29.268: E/AndroidRuntime(9917): at android.os.Looper.loop(Looper.java:137)
08-30 16:13:29.268: E/AndroidRuntime(9917): at android.app.ActivityThread.main
(ActivityThread.java:4921)
08-30 16:13:29.268: E/AndroidRuntime(9917): at java.lang.reflect.Method.invokeNative
(Native Method)
08-30 16:13:29.268: E/AndroidRuntime(9917): at java.lang.reflect.Method.invoke
(Method.java:511)
08-30 16:13:29.268: E/AndroidRuntime(9917): at com.android.internal.os.ZygoteInit
$MethodAndArgsCaller.run(ZygoteInit.java:1027)
08-30 16:13:29.268: E/AndroidRuntime(9917): at com.android.internal.os.ZygoteInit.main
(ZygoteInit.java:794)
08-30 16:13:29.268: E/AndroidRuntime(9917): at dalvik.system.NativeStart.main(Native
Method)
08-30 16:13:29.268: E/AndroidRuntime(9917): Caused by: java.util.NoSuchElementException
08-30 16:13:29.268: E/AndroidRuntime(9917): at java.util.AbstractList
$SimpleListIterator.next(AbstractList.java:59)
08-30 16:13:29.268: E/AndroidRuntime(9917): at
com.example.myapp.DiaryActivity.populateDiaryNew(DiaryActivity.java:71)
08-30 16:13:29.268: E/AndroidRuntime(9917): at
com.example.myapp.DiaryActivity.onCreate(DiaryActivity.java:46)
08-30 16:13:29.268: E/AndroidRuntime(9917): at android.app.Activity.performCreate
(Activity.java:5206)
08-30 16:13:29.268: E/AndroidRuntime(9917): at
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
08-30 16:13:29.268: E/AndroidRuntime(9917): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
08-30 16:13:29.268: E/AndroidRuntime(9917): ... 11 more
所以我只想弄清楚为什么我会得到这个例外。我已经按照一些关于如何为列表视图创建自定义数据适配器的教程，据我所知，已经正确完成了。我一定错过了什么，但我不确定是什么。
很抱歉发布这样的问题，但我是Android新手，我完全被难倒了。非常感谢任何帮助！
答案 0 :(得分：2)
我认为问题的一个可能的地方是，代码如下：
您多次致电iter.next()，但只检查iter.hasNext()一次。
while (iter.hasNext()){
lastEndTime = iter.next().endDateTime;
if (count > 0)
{
if (iter.next().startDateTime.isAfter(lastEndTime))
............................