我在MainActivity中有两个不同的SimpleCursorAdapters和链接的ListView。用以下内容初始化它们：
getLoaderManager().initLoader(0, null, this);
getLoaderManager().initLoader(2, null, this);
初始化后，将创建两个加载器，并在ContentProvider上运行查询并正确返回数据。
LoaderManager实施：
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
CursorLoader loader = null;
switch (id) {
case 0:
loader = new CursorLoader(this,
DataProvider.CONTENT_URI_PROFILE_Match,
new String[]{DataProvider.COL_ID, DataProvider.COL_MATCH_NAME, DataProvider.COL_COUNT, DataProvider.COL_MATCH_PROFILE_IMAGE, DataProvider.COL_MATCH_BIRTH_DATE},
null,
null,
DataProvider.COL_ID + " DESC");
break;
case 2:
loader = new CursorLoader(this,
DataProvider.CONTENT_URI_PROFILE_Trash,
new String[]{DataProvider.COL_ID, DataProvider.COL_MATCH_NAME, DataProvider.COL_EXPIRATION_STATUS, DataProvider.COL_MATCH_PROFILE_IMAGE, DataProvider.COL_MATCH_BIRTH_DATE},
null,
null,
DataProvider.COL_ID + " DESC");
break;
}
return loader;
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
switch (loader.getId()) {
case 0:
adapterMatch.swapCursor(data);
break;
case 2:
adapterTrash.swapCursor(data);
break;
}
}
该应用程序的工作原理如下。当从BroadCastReceiver上的服务器接收消息时，下面的部分代码将在Receiver类上运行并通过ContentProvider在db中插入一行
ContentValues values = new ContentValues(5);
values.put(DataProvider.COL_MATCH_ID, matchedUser);
values.put(DataProvider.COL_EXPIRATION_STATUS, expirationStatus);
values.put(DataProvider.COL_MATCH_NAME, matchName);
values.put(DataProvider.COL_MATCH_BIRTH_DATE, matchBirthDate);
values.put(DataProvider.COL_MATCH_PROFILE_IMAGE, matchProfileImage);
context.getContentResolver().insert(DataProvider.CONTENT_URI_PROFILE_Match, values);
我的问题是在从服务器接收到的新值插入SQLite数据库之后，游标数据不会传递给MainActivity，因此在下次创建Activity之前不会更新UI。
以下是我的ContentProvider中突出显示的代码：
public static final Uri CONTENT_URI_MESSAGES = Uri.parse("content://com.example.vcc4.mashroom.provider/messages");
public static final Uri CONTENT_URI_PROFILE = Uri.parse("content://com.example.vcc4.mashroom.provider/profile");
public static final Uri CONTENT_URI_PROFILE_Match = Uri.parse("content://com.example.vcc4.mashroom.provider/match");
public static final Uri CONTENT_URI_PROFILE_Trash = Uri.parse("content://com.example.vcc4.mashroom.provider/trash");
private static final UriMatcher uriMatcher;
static {
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI("com.example.vcc4.mashroom.provider", "messages", MESSAGES_ALLROWS);
uriMatcher.addURI("com.example.vcc4.mashroom.provider", "messages/#", MESSAGES_SINGLE_ROW);
uriMatcher.addURI("com.example.vcc4.mashroom.provider", "profile", PROFILE_ALLROWS);
uriMatcher.addURI("com.example.vcc4.mashroom.provider", "profile/#", PROFILE_SINGLE_ROW);
uriMatcher.addURI("com.example.vcc4.mashroom.provider", "match", PROFILE_AllROWS_MATCH);
uriMatcher.addURI("com.example.vcc4.mashroom.provider", "match/#", PROFILE_SINGLE_ROWS_MATCH);
uriMatcher.addURI("com.example.vcc4.mashroom.provider", "trash", PROFILE_ALLROWS_TRASH);
}
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
SQLiteDatabase db = dbHelper.getReadableDatabase();
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
switch(uriMatcher.match(uri)) {
case MESSAGES_ALLROWS:
qb.setTables(TABLE_MESSAGES);
break;
case MESSAGES_SINGLE_ROW:
qb.setTables(TABLE_MESSAGES);
qb.appendWhere("_id = " + uri.getLastPathSegment());
break;
case PROFILE_ALLROWS:
qb.setTables(TABLE_PROFILE);
break;
case PROFILE_SINGLE_ROW:
qb.setTables(TABLE_PROFILE);
qb.appendWhere("_id = " + uri.getLastPathSegment());
break;
case PROFILE_AllROWS_MATCH:
qb.setTables(TABLE_PROFILE);
qb.appendWhere(COL_EXPIRATION_STATUS + " = " + "'wait'" + " OR " + COL_EXPIRATION_STATUS + " = " + "'active'");
break;
case PROFILE_ALLROWS_TRASH:
qb.setTables(TABLE_PROFILE);
qb.appendWhere(COL_EXPIRATION_STATUS + " = " + "'expired'");
break;
default:
throw new IllegalArgumentException("Unsupported URI: " + uri);
}
Cursor c = qb.query(db, projection, selection, selectionArgs, null, null, sortOrder);
c.setNotificationUri(getContext().getContentResolver(), uri);
return c;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
SQLiteDatabase db = dbHelper.getWritableDatabase();
long id;
switch(uriMatcher.match(uri)) {
case MESSAGES_ALLROWS:
id = db.insertOrThrow(TABLE_MESSAGES, null, values);
if (values.get(COL_TO) == null) {
db.execSQL("update profile set count = count+1 where email = ?", new Object[]{values.get(COL_FROM)});
getContext().getContentResolver().notifyChange(CONTENT_URI_PROFILE, null);
}
break;
case PROFILE_ALLROWS:
id = db.insertOrThrow(TABLE_PROFILE, null, values);
break;
case PROFILE_AllROWS_MATCH:
id = db.insertOrThrow(TABLE_PROFILE, null, values);
break;
default:
throw new IllegalArgumentException("Unsupported URI: " + uri);
}
Uri insertUri = ContentUris.withAppendedId(uri, id);
getContext().getContentResolver().notifyChange(insertUri, null);
return insertUri;
}
我搜索过很多SO问题和android资源，但找不到解决这个问题的任何线索。有什么解决方案吗？
下面的编辑添加了设置SimpleCursorAdapters的代码：
adapterMatch = new SimpleCursorAdapter(this,
R.layout.main_list_item,
null,
new String[]{DataProvider.COL_MATCH_PROFILE_IMAGE, DataProvider.COL_MATCH_NAME, DataProvider.COL_MATCH_BIRTH_DATE, DataProvider.COL_COUNT, DataProvider.COL_MATCH_ID},
new int[]{R.id.avatar, R.id.text1, R.id.text2, R.id.text3},
0);
adapterWatch = new SimpleCursorAdapter(this,
R.layout.main_list_item,
null,
new String[]{DataProvider.COL_MATCH_PROFILE_IMAGE, DataProvider.COL_MATCH_NAME, DataProvider.COL_MATCH_BIRTH_DATE, DataProvider.COL_MUTUAL_ACTION, DataProvider.COL_EXPIRATION_STATUS, DataProvider.COL_MATCH_ID},
new int[]{R.id.avatar, R.id.text1, R.id.text2, R.id.text3},
0);
adapterTrash = new SimpleCursorAdapter(this,
R.layout.main_list_item,
null,
new String[]{DataProvider.COL_MATCH_PROFILE_IMAGE, DataProvider.COL_MATCH_NAME, DataProvider.COL_MATCH_BIRTH_DATE, DataProvider.COL_EXPIRATION_STATUS},
new int[]{R.id.avatar, R.id.text1, R.id.text2, R.id.text3},
0);
答案 0 :(得分：0)
可能没什么，但您是否介意在插入匹配项时调试并检查insertUri方法的insert方法的第4行ContentProvider变量的值？