当我运行我的应用程序时，按下按钮会强行关闭。我修复了我的Android清单，但我找不到问题。这是Logcat：
03-09 17:46:17.301: D/dalvikvm(2133): Debugger has detached; object registry had 1 entries
03-09 17:46:17.438: D/dalvikvm(2133): GC_EXTERNAL_ALLOC freed 43K, 49% free 2794K/5379K, external 1596K/2108K, paused 95ms
03-09 17:46:17.587: D/dalvikvm(2133): GC_EXTERNAL_ALLOC freed 1K, 49% free 2793K/5379K, external 3471K/4335K, paused 42ms
03-09 17:46:17.825: D/dalvikvm(2133): GC_EXTERNAL_ALLOC freed <1K, 49% free 2795K/5379K, external 5048K/5580K, paused 76ms
03-09 17:46:18.001: D/dalvikvm(2133): GC_EXTERNAL_ALLOC freed <1K, 49% free 2796K/5379K, external 8143K/8403K, paused 44ms
03-09 17:46:49.407: D/dalvikvm(2133): GC_EXTERNAL_ALLOC freed 15K, 48% free 2825K/5379K, external 11785K/11958K, paused 19ms
03-09 17:46:49.544: D/dalvikvm(2133): GC_EXTERNAL_ALLOC freed 1K, 48% free 2826K/5379K, external 13363K/14068K, paused 19ms
03-09 17:46:49.622: D/dalvikvm(2133): GC_EXTERNAL_ALLOC freed <1K, 48% free 2827K/5379K, external 16457K/17091K, paused 19ms
03-09 17:46:49.704: D/AndroidRuntime(2133): Shutting down VM
03-09 17:46:49.704: W/dalvikvm(2133): threadid=1: thread exiting with uncaught exception (group=0x40015578)
03-09 17:46:49.708: E/AndroidRuntime(2133): FATAL EXCEPTION: main
03-09 17:46:49.708: E/AndroidRuntime(2133): java.lang.RuntimeException: Unable to start activity ComponentInfo{izzy.n/izzy.n.main1}: java.lang.NullPointerException
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.os.Handler.dispatchMessage(Handler.java:99)
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.os.Looper.loop(Looper.java:130)
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.app.ActivityThread.main(ActivityThread.java:3687)
03-09 17:46:49.708: E/AndroidRuntime(2133): at java.lang.reflect.Method.invokeNative(Native Method)
03-09 17:46:49.708: E/AndroidRuntime(2133): at java.lang.reflect.Method.invoke(Method.java:507)
03-09 17:46:49.708: E/AndroidRuntime(2133): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
03-09 17:46:49.708: E/AndroidRuntime(2133): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
03-09 17:46:49.708: E/AndroidRuntime(2133): at dalvik.system.NativeStart.main(Native Method)
03-09 17:46:49.708: E/AndroidRuntime(2133): Caused by: java.lang.NullPointerException
03-09 17:46:49.708: E/AndroidRuntime(2133): at izzy.n.main1.populateCalendarSpinner(main1.java:69)
03-09 17:46:49.708: E/AndroidRuntime(2133): at izzy.n.main1.onCreate(main1.java:52)
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-09 17:46:49.708: E/AndroidRuntime(2133): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
03-09 17:46:49.708: E/AndroidRuntime(2133): ... 11 more
以下是Android Manifest的代码：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="izzy.n"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="10" />
<uses-permission android:name="android.permission.READ_CALENDAR"></uses-permission>
<uses-permission android:name="android.permission.WRITE_CALENDAR"></uses-permission>
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name="izzy.n.IzzynActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="izzy.n.notes"
android:label="@string/notes"></activity>
<activity
android:name="izzy.n.calculator"
android:label="@string/calculator"></activity>
<activity android:name="izzy.n.main1"
android:label="@string/app_name"></activity>
</application>
</manifest>
最后这里是main1.java：
class MyCalendar {
public String name;
public String id;
public MyCalendar(String _name, String _id) {
name = _name;
id = _id;
}
@Override
public String toString() {
return name;
}
}
public class main1 extends Activity {
/*********************************************************************
* UI part*/
private Spinner m_spinner_calender;
private Button m_button_add;
private Button m_button_add2;
private Button m_button_getEvents;
private TextView m_text_event;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/*get calendar list and populate the view*/
getCalendars();
populateCalendarSpinner();
populateAddBtn();
populateAddBtn2();
populateTextEvent();
populateGetEventsBtn();
}
private void populateCalendarSpinner() {
m_spinner_calender = (Spinner)this.findViewById(R.id.spinner_calendar);
ArrayAdapter l_arrayAdapter = new ArrayAdapter(this.getApplicationContext(), android.R.layout.simple_spinner_item, m_calendars);
l_arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
m_spinner_calender.setAdapter(l_arrayAdapter);
m_spinner_calender.setSelection(0);
m_spinner_calender.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> p_parent, View p_view,
int p_pos, long p_id) {
m_selectedCalendarId = m_calendars[(int)p_id].id;
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {}
});
}
private void populateAddBtn() {
m_button_add = (Button) this.findViewById(R.id.button_add);
m_button_add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
addEvent();
}
});
}
private void populateAddBtn2() {
m_button_add2 = (Button) this.findViewById(R.id.button_add2);
m_button_add2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
addEvent2();
}
});
}
private void populateGetEventsBtn() {
m_button_getEvents = (Button) findViewById(R.id.button_get_events);
m_button_getEvents.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getLastThreeEvents();
}
});
}
private void populateTextEvent() {
m_text_event = (TextView) findViewById(R.id.text_event);
String l_str = "title: roman10 calendar tutorial test\n" +
"description: This is a simple test for calendar api\n" +
"eventLocation: @home\n" +
"start time:" + getDateTimeStr(0) + "\n" +
"end time: " + getDateTimeStr(30) + "\n" +
"event status: confirmed\n" +
"all day: no\n" +
"has alarm: yes\n";
m_text_event.setText(l_str);
}
/****************************************************************
* Data part
*/
/*retrieve a list of available calendars*/
private MyCalendar m_calendars[];
private String m_selectedCalendarId = "0";
private void getCalendars() {
String[] l_projection = new String[]{"_id", "displayName"};
Uri l_calendars;
if (Build.VERSION.SDK_INT >= 8) {
l_calendars = Uri.parse("content://com.android.calendar/calendars");
} else {
l_calendars = Uri.parse("content://calendar/calendars");
}
Cursor l_managedCursor = this.managedQuery(l_calendars, l_projection, null, null, null); //all calendars
//Cursor l_managedCursor = this.managedQuery(l_calendars, l_projection, "selected=1", null, null); //active calendars
if (l_managedCursor.moveToFirst()) {
m_calendars = new MyCalendar[l_managedCursor.getCount()];
String l_calName;
String l_calId;
int l_cnt = 0;
int l_nameCol = l_managedCursor.getColumnIndex(l_projection[1]);
int l_idCol = l_managedCursor.getColumnIndex(l_projection[0]);
do {
l_calName = l_managedCursor.getString(l_nameCol);
l_calId = l_managedCursor.getString(l_idCol);
m_calendars[l_cnt] = new MyCalendar(l_calName, l_calId);
++l_cnt;
} while (l_managedCursor.moveToNext());
}
}
/*add an event to calendar*/
private void addEvent() {
ContentValues l_event = new ContentValues();
l_event.put("calendar_id", m_selectedCalendarId);
l_event.put("title", "roman10 calendar tutorial test");
l_event.put("description", "This is a simple test for calendar api");
l_event.put("eventLocation", "@home");
l_event.put("dtstart", System.currentTimeMillis());
l_event.put("dtend", System.currentTimeMillis() + 1800*1000);
l_event.put("allDay", 0);
//status: 0~ tentative; 1~ confirmed; 2~ canceled
l_event.put("eventStatus", 1);
//0~ default; 1~ confidential; 2~ private; 3~ public
l_event.put("visibility", 0);
//0~ opaque, no timing conflict is allowed; 1~ transparency, allow overlap of scheduling
l_event.put("transparency", 0);
//0~ false; 1~ true
l_event.put("hasAlarm", 1);
Uri l_eventUri;
if (Build.VERSION.SDK_INT >= 8) {
l_eventUri = Uri.parse("content://com.android.calendar/events");
} else {
l_eventUri = Uri.parse("content://calendar/events");
}
Uri l_uri = this.getContentResolver().insert(l_eventUri, l_event);
Log.v("++++++test", l_uri.toString());
}
/*add an event through intent, this doesn't require any permission
* just send intent to android calendar
* http://www.openintents.org/en/uris*/
private void addEvent2() {
Intent l_intent = new Intent(Intent.ACTION_EDIT);
l_intent.setType("vnd.android.cursor.item/event");
//l_intent.putExtra("calendar_id", m_selectedCalendarId); //this doesn't work
l_intent.putExtra("title", "roman10 calendar tutorial test");
l_intent.putExtra("description", "This is a simple test for calendar api");
l_intent.putExtra("eventLocation", "@home");
l_intent.putExtra("beginTime", System.currentTimeMillis());
l_intent.putExtra("endTime", System.currentTimeMillis() + 1800*1000);
l_intent.putExtra("allDay", 0);
//status: 0~ tentative; 1~ confirmed; 2~ canceled
l_intent.putExtra("eventStatus", 1);
//0~ default; 1~ confidential; 2~ private; 3~ public
l_intent.putExtra("visibility", 0);
//0~ opaque, no timing conflict is allowed; 1~ transparency, allow overlap of scheduling
l_intent.putExtra("transparency", 0);
//0~ false; 1~ true
l_intent.putExtra("hasAlarm", 1);
try {
startActivity(l_intent);
} catch (Exception e) {
Toast.makeText(this.getApplicationContext(), "Sorry, no compatible calendar is found!", Toast.LENGTH_LONG).show();
}
}
/*get a list of events
* http://jimblackler.net/blog/?p=151*/
private void getLastThreeEvents() {
Uri l_eventUri;
if (Build.VERSION.SDK_INT >= 8) {
l_eventUri = Uri.parse("content://com.android.calendar/events");
} else {
l_eventUri = Uri.parse("content://calendar/events");
}
String[] l_projection = new String[]{"title", "dtstart", "dtend"};
Cursor l_managedCursor = this.managedQuery(l_eventUri, l_projection, "calendar_id=" + m_selectedCalendarId, null, "dtstart DESC, dtend DESC");
//Cursor l_managedCursor = this.managedQuery(l_eventUri, l_projection, null, null, null);
if (l_managedCursor.moveToFirst()) {
int l_cnt = 0;
String l_title;
String l_begin;
String l_end;
StringBuilder l_displayText = new StringBuilder();
int l_colTitle = l_managedCursor.getColumnIndex(l_projection[0]);
int l_colBegin = l_managedCursor.getColumnIndex(l_projection[1]);
int l_colEnd = l_managedCursor.getColumnIndex(l_projection[1]);
do {
l_title = l_managedCursor.getString(l_colTitle);
l_begin = getDateTimeStr(l_managedCursor.getString(l_colBegin));
l_end = getDateTimeStr(l_managedCursor.getString(l_colEnd));
l_displayText.append(l_title + "\n" + l_begin + "\n" + l_end + "\n----------------\n");
++l_cnt;
} while (l_managedCursor.moveToNext() && l_cnt < 3);
m_text_event.setText(l_displayText.toString());
}
}
/************************************************
* utility part
*/
private static final String DATE_TIME_FORMAT = "yyyy MMM dd, HH:mm:ss";
public static String getDateTimeStr(int p_delay_min) {
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat(DATE_TIME_FORMAT);
if (p_delay_min == 0) {
return sdf.format(cal.getTime());
} else {
Date l_time = cal.getTime();
l_time.setMinutes(l_time.getMinutes() + p_delay_min);
return sdf.format(l_time);
}
}
public static String getDateTimeStr(String p_time_in_millis) {
SimpleDateFormat sdf = new SimpleDateFormat(DATE_TIME_FORMAT);
Date l_time = new Date(Long.parseLong(p_time_in_millis));
return sdf.format(l_time);
}
}
答案 0 :(得分：1)
如果查看堆栈跟踪，您将从此处看到问题是NullPointerException：
at izzy.n.main1.populateCalendarSpinner(main1.java:69)
main1中第69行的内容为null，但您尝试使用它。我不知道你上面提到的是哪一行，所以很难提供更具体的答案。
这是我的猜测。如果原因来自这一行：
m_selectedCalendarId = m_calendars[(int)p_id].id;
然后m_calendars[(int)p_id]可能没有元素。您真正需要的是：
m_selectedCalendarId = m_calendars[p_pos].id;
为了将来参考， Eclipse Debugger 在这种情况下是一个很好的帮助。这是一个帮助您开始使用它的教程：http://www.ibm.com/developerworks/library/os-ecbug/
答案 1 :(得分：0)
您是否检查过m_calendars是否正确初始化。 确保l_arrayAdapter不为null。