android - 无法从 CursorWindow 读取第 1 行，col -1。在从游标访问数据之前确保正确初始化了游标

Question

我正在实现一个 ExpandableListView 并且对于每个组，它显示子项，每个子项都有自己的持续时间，并且该组显示所有子项持续时间的总和。

但是，当我点击一个 child 时，它会显示错误:

Couldn't read row 1, col -1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.

而且我没有调用方法 setOnChildClickListener。即使我调用它，当我点击 child 时，当我放置断点时它也不会停止。

这就是问题所在，我找不到错误出在哪里，因为堆栈跟踪没有指向我项目的类，而是指向 android native 的类。我已经尝试在我的代码的每个部分放置断点，但是当我点击一个 child 时，没有达到任何断点。

顺便说一句，我使用ViewHolder 模式来处理 View ，适配器是CursorTreeAdapter

这是我的代码 - 完整的堆栈跟踪在最后:

public class MyClass extends ExpandableListActivity
{
    private Cursor mContactsCursor;
    private ExpandableListView mExpandableListView;

    private Integer mContactId;

    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.contacts_layout);   

        mExpandableListView.setOnGroupClickListener(new OnGroupClickListener() 
        {
            @Override
            public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) 
            {
                mContactId = Integer.parseInt(v.getTag(R.id.contact_name).toString());
                return false;
            }
        });
    }

    @Override
    public void onResume()
    {
        super.onResume();
        mContactsCursor = mController.getContacts();
        mExpandableListView.setAdapter(new ContactsExpandableListAdapter(mContactsCursor, this));
    }

    @Override
    public void onPause()
    {
        super.onPause();
        if(!mContactsCursor.isClosed())
            mContactsCursor.close();
    }

    @Override
    public void onDestroy()
    {
        super.onDestroy();
        if(!mContactsCursor.isClosed())
            mContactsCursor.close();
    }

    public class ContactsExpandableListAdapter extends CursorTreeAdapter
    {
        private TextView mContactNameTextView, mContactNumberTextView, mDurationTextView;

        public ContactsExpandableListAdapter(Cursor cursor, Context context) 
        {
            super(cursor, context);
        }

        @Override
        protected Cursor getChildrenCursor(Cursor groupCursor) 
        {
            return mController.getContactById(mContactId);
        }

        @Override
        protected View newGroupView(Context context, Cursor cursor, boolean isExpanded, ViewGroup viewGroup) 
        {
            View view = LayoutInflater.from(context).inflate(R.layout.listitem_contacts, viewGroup, false);

                ViewHolder viewHolder = new ViewHolder();

                viewHolder.contactName = (TextView) view.findViewById(R.id.contact_name);
                viewHolder.duration = (TextView) view.findViewById(R.id.duration);
                viewHolder.groupIndicator = (ImageView) view.findViewById(R.id.indicator_icon);

viewHolder.contactName.setText(cursor.getString(cursor.getColumnIndex("contact_name")));

                // Set the duration to the view
                viewHolder.duration.setText(cursor.getString(cursor.getColumnIndex("duration_sum")));

                // Set the tags to the view to be used later when the user click the group view.
                // These tags are the contact number, contact id and the the view holder object
                // to be retrieved when binding the group view
                view.setTag(R.id.contact_number, cursor.getString(cursor.getColumnIndex("contact_number")));
                view.setTag(R.id.rlt_main, viewHolder);
                view.setTag(R.id.contact_name, cursor.getString(cursor.getColumnIndex("contact_id")));
            }

            return view;
        }

        @Override
        protected View newChildView(Context context, Cursor cursor, boolean isLastChild, ViewGroup viewGroup) 
        {
            View view = LayoutInflater.from(context).inflate(R.layout.listitem_contacts, viewGroup, false);

                    mContactNumberTextView = (TextView) view.findViewById(R.id.phone_number);
                    mContactNumberTextView.setText(cursor.getString(cursor.getColumnIndex("contact_name")));

                mDurationTextView = (TextView) view.findViewById(R.id.duration);
                mDurationTextView.setText(cursor.getString(cursor.getColumnIndex("duration")));

                view.setTag(cursor.getString(cursor.getColumnIndex("contact_number")));

            return view;
        }

        @Override
        protected void bindGroupView(View view, Context context, Cursor cursor, boolean isExpanded) 
        {
                ViewHolder viewHolder = (ViewHolder) view.getTag(R.id.rlt_main);

                // For each view created, make a query to the database based on the contact id.
                // This is not very wise to do, but will probably be changed in the future.
                Integer contactId = cursor.getInt(cursor.getColumnIndex("contact_id"));

                // Check if the current contact id is equal to -1. If yes it means the contact

                Cursor currentContactCursor = mFilterByContactController.getContactById(contactId); 

                // Check if the cursor being retrieved from the database based on the current view cursor
                // is major than zero. If yes, it means it has children, so set the indicator icon to this
                // view as visible. If not, set the indicator for this view as gone.
                if(currentContactCursor != null && currentContactCursor.getCount() > 0)
                {
                    viewHolder.groupIndicator.setVisibility(View.VISIBLE);
                    viewHolder.groupIndicator.setImageResource(isExpanded ? R.drawable.expander_ic_maximized : R.drawable.expander_ic_minimized);
                }
                else
                {
                    viewHolder.groupIndicator.setVisibility(View.GONE);
                }

                if(cursor.getString(cursor.getColumnIndex("contact_name")) == null)
                    viewHolder.contactName.setText(cursor.getString(cursor.getColumnIndex("contact_number")));
                else
                    viewHolder.contactName.setText(cursor.getString(cursor.getColumnIndex("contact_name")));

                // Set the duration to the view
                viewHolder.duration.setText(Utils.convertTime(Integer.parseInt(cursor.getString(cursor.getColumnIndex("duration_sum")))));

                // Set the tags to the view to be used later when the user click the group view
                view.setTag(R.id.contact_number, cursor.getString(cursor.getColumnIndex("contact_number")));
                view.setTag(R.id.contact_name, cursor.getString(cursor.getColumnIndex("contact_id")));

                if(!currentContactCursor.isClosed())
                    currentContactCursor.close();
            }
        }

        @Override
        protected void bindChildView(View view, Context context, Cursor cursor, boolean expanded) 
        {
            try
            {
                    if(cursor.getString(cursor.getColumnIndex("contact_name")) == null)
                    {
                        mContactNameTextView = (TextView) view.findViewById(R.id.contact_name);
                        mContactNameTextView.setText(cursor.getString(cursor.getColumnIndex("phone_number")));
                    }
                    else
                    {
                        mContactNumberTextView = (TextView) view.findViewById(R.id.phone_number);
                        mContactNumberTextView.setText(cursor.getString(cursor.getColumnIndex("contact_number")));
                    }

                    mDurationTextView = (TextView) view.findViewById(R.id.duration);
                    mDurationTextView.setText(cursor.getString(cursor.getColumnIndex("duration")));

            }
            catch(Exception e)
            {
                e.printStackTrace();
            }
            finally
            {
                if(cursor.isClosed())
                    cursor.close();
            }
        }
    }

完整堆栈跟踪

07-22 16:47:46.388: E/AndroidRuntime(7718): java.lang.IllegalStateException: Couldn t read row 1, col -1 from CursorWindow.  Make sure the Cursor is initialized correctly before accessing data from it. 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.database.CursorWindow.nativeGetLong(Native Method) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.database.CursorWindow.getLong(CursorWindow.java:515) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.database.AbstractWindowedCursor.getLong(AbstractWindowedCursor.java:75)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.widget.CursorTreeAdapter$MyCursorHelper.getId(CursorTreeAdapter.java:436)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.widget.CursorTreeAdapter.getChildId(CursorTreeAdapter.java:173)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.widget.ExpandableListConnector.getItemId(ExpandableListConnector.java:427)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.widget.AdapterView.getItemIdAtPosition(AdapterView.java:756)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.widget.AdapterView.setSelectedPositionInt(AdapterView.java:1128)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.widget.AbsListView.onTouchEvent(AbsListView.java:3147) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.View.dispatchTouchEvent(View.java:5541)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:1951)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1712) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:1957)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1726) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:1957)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1726) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:1957)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1726) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:1957)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1726)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1912)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1371)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.app.Activity.dispatchTouchEvent(Activity.java:2364) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1860)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.View.dispatchPointerEvent(View.java:5721)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:2890)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2466)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewRootImpl.processInputEvents(ViewRootImpl.java:845)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2475) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.os.Handler.dispatchMessage(Handler.java:99) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at android.os.Looper.loop(Looper.java:137) 07-22 16:47:46.388: E/AndroidRuntime(7718):  at android.app.ActivityThread.main(ActivityThread.java:4424)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at java.lang.reflect.Method.invokeNative(Native Method)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at java.lang.reflect.Method.invoke(Method.java:511) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-22 16:47:46.388: E/AndroidRuntime(7718):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
07-22 16:47:46.388: E/AndroidRuntime(7718):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

正如@Jens 在评论中提到的:

Is it looking for a row identifier (i.e. BaseColumns#_ID) and not finding it in the cursor? Which columns are you using in mContactsCursor - you haven't forgotten the row id in that?

在所有查询中，必须指定列 _id。这就是导致错误的原因，在我将 _id 列添加到查询后，它起作用了。