getLoaderManager().initLoader() 不接受“this"作为参数，尽管类 (ListFragment) 实现了 LoaderManager.LoaderCallbacks<Cursor> [英] getLoaderManager().initLoader() doesn't accept 'this' as argument though the class (ListFragment) implements LoaderManager.LoaderCallbacks<Cursor>

问题描述

我在遵循有关在 Android 中使用 SQLite 的指南时遇到问题.我使用的是 ListFragment 而不是 ListActivity(如示例中所示)，所以我有 ListFragment 实现 LoaderManager.LoaderCallbacks<Cursor> 代替.然后，在ListFragment的fillData()方法中:

I'm having trouble following a guide on using SQLite in Android. I'm using a ListFragment instead of a ListActivity(as in the example), so I have the ListFragment implement LoaderManager.LoaderCallbacks<Cursor> instead. Then, in the fillData() method in the ListFragment:

private void fillData() {
    // Fields from the database (projection)
    // Must include the _id column for the adapter to work
    String[] from = new String[] { NotesSQLiteHelper.COLUMN_TITLE };
    // Fields on the UI to which we map
    int[] to = new int[] { R.id.label };

    getLoaderManager().initLoader(0, null, this); //error
    adapter = new SimpleCursorAdapter(getApplicationContext(), R.layout.notes_row, null, from, to, 0);
    setListAdapter(adapter);
}

我收到错误:

The method initLoader(int, Bundle, LoaderManager.LoaderCallbacks<D>) in the type LoaderManager is not applicable for the arguments (int, null, NotesActivity.ArrayListFragment)

在标记的行上，即使 this 实现了 LoaderManager.LoaderCallbacks.

on the marked line even though this implements LoaderManager.LoaderCallbacks<Cursor>.

感谢您的任何想法.

推荐答案

您没有使用正确的 CursorLoader 和 Loader 实现.删除旧的导入并使用这些导入:

You are not using the right implementations of CursorLoader and Loader. Remove your old imports and use these ones:

import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.CursorAdapter;

但是我在使用 SherlockActionBar 时遇到了同样的问题:因为我必须扩展 SherlockListActivity，所以没有方法 getSupportLoadManager().

But I have the same Problem using SherlockActionBar: As I have to extend SherlockListActivity there is NO method getSupportLoadManager().

对此有什么想法吗?

按照 本教程 如果您不知道如何使用片段.创建一个带有 extends SherlockFragment 的新类并将您的显示逻辑移到那里.使您的旧活动扩展 SherlockFragmentActivity 并显示新创建的 SherlockFragment.这样我就让它工作了.感谢@JakeWharton！

follow this tutorial if you do not know how to use fragments. Create a new Class with extends SherlockFragment and move your display logic there. Make your old activity extend SherlockFragmentActivity and show the newly created SherlockFragment. This way I got it working. Thanks to @JakeWharton!

这篇关于getLoaderManager().initLoader() 不接受“this"作为参数，尽管类 (ListFragment) 实现了 LoaderManager.LoaderCallbacks<Cursor>的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！