CalendarProvider：游标始终为空

Question

所以我试图从特定的日历 ID 中获取今天的每个事件。我在编写、更新和删除事件时没有遇到任何问题，但我无法开始阅读。

这是我的代码：

    String[] query= new String[]{
            Events.CALENDAR_ID,
            Events.TITLE,
            Events.DESCRIPTION,
            Events.DTSTART,
            Events.HAS_ATTENDEE_DATA,
            Attendees.ATTENDEE_NAME,
            Attendees.ATTENDEE_EMAIL
    };

    String selection = "(( " + Events.DTSTART + " >= " + today.getTime() + " ))";

    if (ActivityCompat.checkSelfPermission(activity, Manifest.permission.READ_CALENDAR) != PackageManager.PERMISSION_GRANTED) {
        return null;
    }
    Cursor cur = activity.getBaseContext().getContentResolver().query(Events.CONTENT_URI, query, selection, null, null);

    Log.d("CalendarUtility","is cursor null : "+Boolean.toString(cur==null)); // always prints true

我试过没有最小日期，但我的光标仍然是空的。以防万一，因为 API 更新会改变一切： compileSdkVersion 25、minSdkVersion 21

Answer 1

我找到了它不起作用的原因。我的查询尝试访问 CalendarContract.Attendees（使用 Attendees.ATTENDEE_NAME 和 Attendees.ATTENDEE_EMAIL），但我的 Cursor 是为了 return CalendarContract.Events table.

所以这就是我所做的：

private static String[] EVENTS_QUERY = new String[]{
        Events._ID,
        Events.CALENDAR_ID,
        Events.TITLE,
        Events.DESCRIPTION,
        Events.DTSTART,
        Events.HAS_ATTENDEE_DATA
        // No Attendees columns
};

private static String EVENTS_SELECTION = "(( " + Events.DTSTART + " >= " + nowTimeInMillis + " ))";

//...


Cursor cur = activity.getContentResolver().query(Events.CONTENT_URI, EVENTS_QUERY, EVENTS_SELECTION, null, null);

以后，如果我的活动有与会者数据：

String[] ATTENDEES_QUERY = new String[]{
                                Attendees.EVENT_ID,
                                Attendees.ATTENDEE_NAME,
                                Attendees.ATTENDEE_EMAIL
                        };
String ATTENDEES_SELECTION =  "(( " + Attendees.EVENT_ID + " == " + eventId + " ))";
Cursor att = activity.getContentResolver().query(Attendees.CONTENT_URI,ATTENDEES_QUERY,ATTENDEES_SELECTION,null,null);

CalendarProvider：游标始终为空

CalendarProvider : cursor always null

android

android-calendar