android.support.v4.app.LoaderManager#restartLoader ( )源码实例Demo

private void loadListViewItems(int listPosition, boolean markSeen, boolean showProgress) {
    if (!isAdded()) {
        return;
    }
    int loaderId = 0;
    ConversationsLoaderCallbacks callbacks =
            new ConversationsLoaderCallbacks(getContext(), listView,
                    listPosition, cursorAdapter, markSeen, showProgress);

    LoaderManager manager = getLoaderManager();
    Loader<?> loader = manager.getLoader(loaderId);
    if (loader == null) {
        // init and run the items loader
        manager.initLoader(loaderId, null, callbacks);
    } else {
        // restart loader
        manager.restartLoader(loaderId, null, callbacks);
    }
}
 

private void loadListViewItems(String itemsFilter, boolean deleteItems, int listPosition) {
    if (!isAdded()) {
        return;
    }
    int loaderId = 0;
    JournalItemsLoaderCallbacks callbacks =
            new JournalItemsLoaderCallbacks(getContext(), cursorAdapter,
                    itemsFilter, deleteItems, listView, listPosition);
    LoaderManager manager = getLoaderManager();
    if (manager.getLoader(loaderId) == null) {
        // init and run the items loader
        manager.initLoader(loaderId, null, callbacks);
    } else {
        // restart loader
        manager.restartLoader(loaderId, null, callbacks);
    }
}
 

private void loadListViewItems(int threadId, int unreadCount, int listPosition) {
    if (!isAdded()) {
        return;
    }
    int loaderId = 0;
    ConversationLoaderCallbacks callbacks =
            new ConversationLoaderCallbacks(getContext(),
                    threadId, unreadCount, listView, listPosition, cursorAdapter);

    LoaderManager manager = getLoaderManager();
    if (manager.getLoader(loaderId) == null) {
        // init and run the items loader
        manager.initLoader(loaderId, null, callbacks);
    } else {
        // restart loader
        manager.restartLoader(loaderId, null, callbacks);
    }
}
 

private void loadListViewItems(String itemsFilter, boolean deleteItems, int listPosition) {
    if (!isAdded()) {
        return;
    }
    int loaderId = 0;
    ContactsLoaderCallbacks callbacks =
            new ContactsLoaderCallbacks(getContext(), contactType, cursorAdapter,
                    itemsFilter, deleteItems, listView, listPosition);
    LoaderManager manager = getLoaderManager();
    if (manager.getLoader(loaderId) == null) {
        // init and run the items loader
        manager.initLoader(loaderId, null, callbacks);
    } else {
        // restart loader
        manager.restartLoader(loaderId, null, callbacks);
    }
}
 

public void loadNext(View view){
    //获取LoaderManager
    LoaderManager loaderManager = getSupportLoaderManager();
    //LoaderManager.restartLoader
    loaderManager.restartLoader(1,null,this);

}
 

/**
 * Re-query database.
 *
 * @param forceUpdate force update
 */
public void requery(final boolean forceUpdate) {
    Log.d(TAG, "requery(", forceUpdate, ")");
    if (!this.ignoreQuery) {
        LoaderManager lm = getLoaderManager();
        if (forceUpdate && lm.getLoader(uid) != null) {
            lm.restartLoader(uid, null, this);
        } else {
            lm.initLoader(uid, null, this);
        }
    } else {
        Log.d(TAG, "requery(", forceUpdate, "): ignore");
    }
}
 

/**
 * This method retrieves the search text from the EditText, constructs the
 * URL (using {@link NetworkUtils}) for the github repository you'd like to find, displays
 * that URL in a TextView, and finally request that an AsyncTaskLoader performs the GET request.
 */
private void makeGithubSearchQuery() {
    String githubQuery = mSearchBoxEditText.getText().toString();

    /*
     * If the user didn't enter anything, there's nothing to search for. In the case where no
     * search text was entered but the search button was clicked, we will display a message
     * stating that there is nothing to search for and we will not attempt to load anything.
     *
     * If there is text entered in the search box when the search button was clicked, we will
     * create the URL that will return our Github search results, display that URL, and then
     * pass that URL to the Loader. The reason we pass the URL as a String is simply a matter
     * of convenience. There are other ways of achieving this same result, but we felt this
     * was the simplest.
     */
    if (TextUtils.isEmpty(githubQuery)) {
        mUrlDisplayTextView.setText("No query entered, nothing to search for.");
        return;
    }

    URL githubSearchUrl = NetworkUtils.buildUrl(githubQuery);
    mUrlDisplayTextView.setText(githubSearchUrl.toString());

    Bundle queryBundle = new Bundle();
    queryBundle.putString(SEARCH_QUERY_URL_EXTRA, githubSearchUrl.toString());

    /*
     * Now that we've created our bundle that we will pass to our Loader, we need to decide
     * if we should restart the loader (if the loader already existed) or if we need to
     * initialize the loader (if the loader did NOT already exist).
     *
     * We do this by first store the support loader manager in the variable loaderManager.
     * All things related to the Loader go through through the LoaderManager. Once we have a
     * hold on the support loader manager, (loaderManager) we can attempt to access our
     * githubSearchLoader. To do this, we use LoaderManager's method, "getLoader", and pass in
     * the ID we assigned in its creation. You can think of this process similar to finding a
     * View by ID. We give the LoaderManager an ID and it returns a loader (if one exists). If
     * one doesn't exist, we tell the LoaderManager to create one. If one does exist, we tell
     * the LoaderManager to restart it.
     */
    LoaderManager loaderManager = getSupportLoaderManager();
    Loader<String> githubSearchLoader = loaderManager.getLoader(GITHUB_SEARCH_LOADER);
    if (githubSearchLoader == null) {
        loaderManager.initLoader(GITHUB_SEARCH_LOADER, queryBundle, this);
    } else {
        loaderManager.restartLoader(GITHUB_SEARCH_LOADER, queryBundle, this);
    }
}
 

/**
 * Set Adapter.
 *
 * @param forceUpdate force update
 */
public void setAdapter(final boolean forceUpdate) {
    LogAdapter adapter = (LogAdapter) getListAdapter();
    if (!forceUpdate && adapter != null && !adapter.isEmpty()) {
        return;
    }

    String where = DataProvider.Logs.TABLE + "." + DataProvider.Logs.TYPE + " in (-1";
    if (tbCall != null && tbCall.isChecked()) {
        where += "," + DataProvider.TYPE_CALL;
    }
    if (tbSMS != null && tbSMS.isChecked()) {
        where += "," + DataProvider.TYPE_SMS;
    }
    if (tbMMS != null && tbMMS.isChecked()) {
        where += "," + DataProvider.TYPE_MMS;
    }
    if (tbData != null && tbData.isChecked()) {
        where += "," + DataProvider.TYPE_DATA;
    }
    where += ") and " + DataProvider.Logs.TABLE + "." + DataProvider.Logs.DIRECTION + " in (-1";
    if (tbIn != null && tbIn.isChecked()) {
        where += "," + DataProvider.DIRECTION_IN;
    }
    if (tbOut != null && tbOut.isChecked()) {
        where += "," + DataProvider.DIRECTION_OUT;
    }
    where += ")";

    if (planId > 0L && tbPlan != null && tbPlan.isChecked()) {
        String plans = DataProvider.Plans.parseMergerWhere(getActivity()
                .getContentResolver(), planId);
        where = DbUtils.sqlAnd(plans, where);
        Log.d(TAG, "where: ", where);
    }
    Bundle args = new Bundle(1);
    args.putString("where", where);

    LoaderManager lm = getLoaderManager();
    if (lm.getLoader(LOADER_UID) == null) {
        lm.initLoader(LOADER_UID, args, this);
    } else {
        lm.restartLoader(LOADER_UID, args, this);
    }
}