我正在制作活动日历..
我遇到了问题。我的活动日历应用程序在三星Galaxy Y和HTC设备中工作正常，但当我在三星Galaxy Tab 2中运行apk时，它会抛出下面logcat中显示的错误。我无法找到解决方案。
logcat的
09-03 12:24:08.703: E/AndroidRuntime(8676): FATAL EXCEPTION: main
09-03 12:24:08.703: E/AndroidRuntime(8676): java.lang.NullPointerException
09-03 12:24:08.703: E/AndroidRuntime(8676): at com.examples.android.calendar.Utility.readCalendarEvent(Utility.java:36)
09-03 12:24:08.703: E/AndroidRuntime(8676): at com.examples.android.calendar.CalendarView$1.run(CalendarView.java:184)
CalendarView.java
public class CalendarView extends Activity {
public GregorianCalendar month, itemmonth;// calendar instances.
public CalendarAdapter adapter;// adapter instance
public Handler handler;// for grabbing some event values for showing the dot
// marker.
public ArrayList<String> items; // container to store calendar items which
// needs showing the event marker
ArrayList<String> event;
LinearLayout rLayout;
ArrayList<String> date;
ArrayList<String> desc;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.calendar);
Locale.setDefault(Locale.US);
rLayout = (LinearLayout) findViewById(R.id.text);
month = (GregorianCalendar) GregorianCalendar.getInstance();
itemmonth = (GregorianCalendar) month.clone();
items = new ArrayList<String>();
adapter = new CalendarAdapter(this, month);
GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(adapter);
handler = new Handler();
handler.post(calendarUpdater);
TextView title = (TextView) findViewById(R.id.title);
title.setText(android.text.format.DateFormat.format("MMMM yyyy", month));
RelativeLayout previous = (RelativeLayout) findViewById(R.id.previous);
previous.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
setPreviousMonth();
refreshCalendar();
}
});
RelativeLayout next = (RelativeLayout) findViewById(R.id.next);
next.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
setNextMonth();
refreshCalendar();
}
});
gridview.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
// removing the previous view if added
if (((LinearLayout) rLayout).getChildCount() > 0) {
((LinearLayout) rLayout).removeAllViews();
}
desc = new ArrayList<String>();
date = new ArrayList<String>();
((CalendarAdapter) parent.getAdapter()).setSelected(v);
String selectedGridDate = CalendarAdapter.dayString
.get(position);
String[] separatedTime = selectedGridDate.split("-");
String gridvalueString = separatedTime[2].replaceFirst("^0*",
"");// taking last part of date. ie; 2 from 2012-12-02.
int gridvalue = Integer.parseInt(gridvalueString);
// navigate to next or previous month on clicking offdays.
if ((gridvalue > 10) && (position < 8)) {
setPreviousMonth();
refreshCalendar();
} else if ((gridvalue < 7) && (position > 28)) {
setNextMonth();
refreshCalendar();
}
((CalendarAdapter) parent.getAdapter()).setSelected(v);
for (int i = 0; i < Utility.startDates.size(); i++) {
if (Utility.startDates.get(i).equals(selectedGridDate)) {
desc.add(Utility.nameOfEvent.get(i));
}
}
if (desc.size() > 0) {
for (int i = 0; i < desc.size(); i++) {
TextView rowTextView = new TextView(CalendarView.this);
// set some properties of rowTextView or something
rowTextView.setText("Event:" + desc.get(i));
rowTextView.setTextColor(Color.BLACK);
// add the textview to the linearlayout
rLayout.addView(rowTextView);
}
}
desc = null;
}
});
}
protected void setNextMonth() {
if (month.get(GregorianCalendar.MONTH) == month
.getActualMaximum(GregorianCalendar.MONTH)) {
month.set((month.get(GregorianCalendar.YEAR) + 1),
month.getActualMinimum(GregorianCalendar.MONTH), 1);
} else {
month.set(GregorianCalendar.MONTH,
month.get(GregorianCalendar.MONTH) + 1);
}
}
protected void setPreviousMonth() {
if (month.get(GregorianCalendar.MONTH) == month
.getActualMinimum(GregorianCalendar.MONTH)) {
month.set((month.get(GregorianCalendar.YEAR) - 1),
month.getActualMaximum(GregorianCalendar.MONTH), 1);
} else {
month.set(GregorianCalendar.MONTH,
month.get(GregorianCalendar.MONTH) - 1);
}
}
protected void showToast(String string) {
Toast.makeText(this, string, Toast.LENGTH_SHORT).show();
}
public void refreshCalendar() {
TextView title = (TextView) findViewById(R.id.title);
adapter.refreshDays();
adapter.notifyDataSetChanged();
handler.post(calendarUpdater); // generate some calendar items
title.setText(android.text.format.DateFormat.format("MMMM yyyy", month));
}
public Runnable calendarUpdater = new Runnable() {
@Override
public void run() {
items.clear();
// Print dates of the current week
DateFormat df = new SimpleDateFormat("yyyy-MM-dd", Locale.US);
String itemvalue;
event = Utility.readCalendarEvent(CalendarView.this); ///Line 184
Log.d("=====Event====", event.toString());
Log.d("=====Date ARRAY====", Utility.startDates.toString());
for (int i = 0; i < Utility.startDates.size(); i++) {
itemvalue = df.format(itemmonth.getTime());
itemmonth.add(GregorianCalendar.DATE, 1);
items.add(Utility.startDates.get(i).toString());
}
adapter.setItems(items);
adapter.notifyDataSetChanged();
}
};
}
Utility.java
public class Utility {
public static ArrayList<String> nameOfEvent = new ArrayList<String>();
public static ArrayList<String> startDates = new ArrayList<String>();
public static ArrayList<String> endDates = new ArrayList<String>();
public static ArrayList<String> descriptions = new ArrayList<String>();
public static ArrayList<String> readCalendarEvent(Context context) {
Cursor cursor = context.getContentResolver()
.query(Uri.parse("content://com.android.calendar/events"),
new String[] { "calendar_id", "title", "description",
"dtstart", "dtend", "eventLocation" }, null,
null, null);
cursor.moveToFirst();
// fetching calendars name
String CNames[] = new String[cursor.getCount()];
// fetching calendars id
nameOfEvent.clear();
startDates.clear();
endDates.clear();
descriptions.clear();
for (int i = 0; i < CNames.length; i++) {
nameOfEvent.add(cursor.getString(1));
startDates.add(getDate(Long.parseLong(cursor.getString(3).trim())));
endDates.add(getDate(Long.parseLong(cursor.getString(4).trim())));
descriptions.add(cursor.getString(2));
CNames[i] = cursor.getString(1);
cursor.moveToNext();
}
return nameOfEvent;
}
public static String getDate(long milliSeconds) {
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(milliSeconds);
return formatter.format(calendar.getTime());
}}