ContentObserver 在仪器测试期间从未收到 onChange 回调？

Question

在为我的内容提供商编写测试时，我偶然发现了一个奇怪的问题。以下代码只是尝试在基础数据更改时验证对我的 ContentObserver 的调用。但是 onChange 回调 ContentObserverMock 永远不会被调用。如果我直接在 ContentResolver 或 Cursor 上尝试它也没有什么区别。这是我的测试：

public class TestCursor extends AndroidTestCase {

    private class ContentObserverMock extends ContentObserver {

        public boolean  cursorObserverIsTriggered   = false;


        /**
         * @param handler
         */
        public ContentObserverMock(Handler handler) {
            super(handler);
        }


        @Override
        public boolean deliverSelfNotifications() {
            return true;
        }


        /**
         * {@inheritDoc}
         */
        @Override
        public void onChange(boolean selfChange) {
            Log.d(TestCursor.TAG, "ONCHANGE is called");
            cursorObserverIsTriggered = true;
            super.onChange(selfChange);
        }
    }

    private final static String TAG = TestCursor.class.getSimpleName();


    /**
     * {@inheritDoc}
     */
    @Override
    protected void setUp() throws Exception {
        super.setUp();
        Globals.setApplicationContext(getContext());
        DummyDataDB.insertDummyDataIntoDB();
    }


    /**
     * {@inheritDoc}
     */
    @Override
    protected void tearDown() throws Exception {
        super.tearDown();
        DummyDataDB.clearDB();
    }


    @SmallTest
    public void testContentResolver() {

        ContentResolver resolver = getContext().getContentResolver();

        Uri uri = MyContentProvider.CONTENT_URI;

        Handler handler = new Handler();
        ContentObserverMock contentObserver = new ContentObserverMock(handler);

        resolver.registerContentObserver(uri, true, contentObserver);

        Cursor cursor = resolver.query(uri, null, null, null, null);
        Assert.assertNotNull(cursor);
        int count = cursor.getCount();

        DomainObject contentStub = StubFactory.createContentStub();
        ContentValues cv = HelperDomainObjectToContentValues.contentValuesFor(contentStub );

        resolver.insert(uri, cv);
        cursor = resolver.query(uri, null, null, null, null);

        Assert.assertEquals(count, (cursor.getCount() - 1));
        Assert.assertEquals(true, contentObserver.cursorObserverIsTriggered);
    }


    @SmallTest
    public void testCursor() {

        Log.d(TestCursor.TAG, "testCursor()");
        DbHelper dbHelper = new DbHelper(getContext());
        Cursor cursor = dbHelper.selectAllDomainObjects();

        Handler handler = new Handler();

        ContentObserverMock contentObserver = new ContentObserverMock(handler);
        Log.d(TestCursor.TAG, "registerContentObserver()");
        cursor.registerContentObserver(contentObserver);

        DomainObject contentStub = StubFactory.createContentStub();
        ContentValues cv = HelperDomainObjectToContentValues.contentValuesFor(contentStub );
        dbHelper.writeDOmainObject(contentValues);
        Log.d(TestCursor.TAG, "cursor Requery()");
        cursor.requery();

        Assert.assertEquals(true, contentObserver.cursorObserverIsTriggered);
    }

提前致谢！

Answer 1

我通过在我的活动上使用访问器来获取处理程序的引用解决了这个问题。定义处理程序后，ContentObserver 会收到预期的回调......