Question

在我的活动中，我有2个CursorLoader和2个带有OnClickListener的TextView，它调用setScreen（）方法。有时单击Textviews我有错误

11-29 15:27:26.045: INFO/dalvikvm(1223): Ljava/lang/IllegalStateException;: Finalizing cursor android.database.sqlite.SQLiteCursor@43c02e18 on MAIN_TABLE that has not been deactivated or closed
11-29 15:27:26.045: INFO/dalvikvm(1223):     at android.database.sqlite.SQLiteCursor.finalize(SQLiteCursor.java:596)
11-29 15:27:26.045: INFO/dalvikvm(1223):     at dalvik.system.NativeStart.run(Native Method)
11-29 15:27:26.065: INFO/dalvikvm(1223): Uncaught exception thrown by finalizer (will be discarded):

完整的代码是

public class ActivityMatchesList extends FragmentActivity implements LoaderManager.LoaderCallbacks<Cursor> {
    private MyAdapter1 mAdapter1;
    private MyAdapter2 mAdapter2;
    private int mTab;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        /** Cursor Loader */
        getSupportLoaderManager().initLoader(1, null, this);
        getSupportLoaderManager().initLoader(2, null, this);
        /** set content view */
        setContentView(R.layout.main_list);
        View vv = new View(this);
        LinearLayout ll = (LinearLayout) findViewById(R.id.boxRanking);
        vv = View.inflate(this, R.layout.tab_ranking, null);
        ll.addView(vv, new LinearLayout.LayoutParams(ll.getLayoutParams().width, ll.getLayoutParams().height));
        /** set colors */
        ListView lvLive = (ListView)findViewById(R.id.matchListList);
        ListView lvLeagueMatches = (ListView) findViewById(R.id.listLeagueMatches);
        /** create and set Adapters */
        mAdapter1 =     new MyAdapter1(
            this, 
            R.layout.main_list_row, 
            null,
            0);
        mAdapter2 = new MyAdapter2(
            this, 
            R.layout.list_ran_row, 
            null,
            0);
        lvLive.setAdapter(mAdapter1);
        lvLeagueMatches.setAdapter(mAdapter2);          

        /** listener */
        TextView tabLive = (TextView) findViewById(R.id.tab_main);
        TextView tabRank = (TextView) findViewById(R.id.tab_ran);
        tabLive.setOnClickListener(onClickListenerTab);
        tabRank.setOnClickListener(onClickListenerTab);
    }

    @Override
    protected void onResume() {
        super.onResume();
        setScreen();
    }

    private void setScreen() {
        if (mTab!=Constants.Tab.TAB_2) mTab=Constants.Tab.TAB_1;
        LinearLayout llRanking = (LinearLayout) findViewById(R.id.boxRanking);
        ListView lvLive = (ListView)findViewById(R.id.matchListList);
        switch (mTab){
            case Constants.Tab.TAB_1:
                llRanking.setVisibility(View.GONE);
                lvLive.setVisibility(View.VISIBLE);
                break;
            case Constants.Tab.TAB_2:
                llRanking.setVisibility(View.VISIBLE);
                lvLive.setVisibility(View.GONE);
                break;  
        }
        getContentResolver().notifyChange(MyProvider.CONTENT_URI, null);
    }

    private OnClickListener onClickListenerTab = new OnClickListener() {
        public void onClick(final View v) {
            int mNewTab;
            if(v.getId()==R.id.tab_ran){
                mNewTab = Constants.Tab.TAB_2;
            } else {
                mNewTab = Constants.Tab.TAB_1;
            } 
            if (mTab != mNewTab) {
                mTab = mNewTab;
                setScreen();
            }
        }
    };

    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
        switch (id){
        case 1:
            CursorLoader cursorLoaderLive = new CursorLoader(
                this, 
                MyProvider.CONTENT_URI_MAIN, 
                null, 
                null, 
                null, 
                "MatchDateYear, MatchDateMonth, MatchDateDay, MatchHour, MatchMinute");
            return cursorLoaderLive;
        case 2:
            CursorLoader cursorLoaderRankingLeague = new CursorLoader(
                this, 
                MyProvider.CONTENT_URI_RAN, 
                null, 
                "Round=3 AND IsMatch=1", 
                null, 
                null);
            return cursorLoaderRankingLeague;
        default:
            return null;
        }
    }

    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
        switch (loader.getId()){
        case 1:
            mAdapter1.swapCursor(cursor);
            break;
        case 2:
            mAdapter2.swapCursor(cursor);
            break;
        }
    }

    @Override
    public void onLoaderReset(Loader<Cursor> loader) {
        switch (loader.getId()){
        case 1:
            mAdapter1.swapCursor(null);
            break;
        case 2:
            mAdapter2.swapCursor(null);
            break;
        }
    }
}

为什么CursorLoader会出现此错误？我读到CursorLoader应该管理光标并在必要时关闭它。

Answer 1

不确定这是否与您的问题有关，但请注意：

在创建适配器之前，我不会调用getSupportLoaderManager().initLoader()。也许它有效，但如果在创建适配器之前调用onLoadFinished()，我觉得它可能会导致问题。
为什么要在getContentResolver().notifyChange()方法中调用setScreen()？据我所知，notifyChange()用于通知内容提供商中的数据已更改，但它并不像我在改变任何内容。从我对内容提供商的有限使用来看，我只在内容提供者类本身中调用ContentResolver.notifyChange()。请参阅此处的示例：http://developer.android.com/resources/samples/NotePad/src/com/example/android/notepad/NotePadProvider.html
这真的很挑剔，但在onCreateLoader()你可以这样做：
```
return new CursorLoader(
```
而不是创建未使用的引用。
最后，为了得到实际的问题，我唯一一次看到这个错误就是当我有一个我没有关闭的打开游标时。由于CursorLoader处理游标生命周期，因此我希望确保您的应用程序中没有其他任何地方可以打开游标，例如调用getContentResolver().query()或直接查询数据库。
< / LI>
如果以上都不起作用，也许您可以将使用单独的CursorLoaders处理的数据拆分为单独的CursorProviders。

CursorLoader和Finalizing游标尚未停用或关闭错误

1 个答案: