Question

I m trying to fill a grid view using data from a db cursor using a custom SimpleCursorAdapter. My cursor has data (I checked), but nothing is shown in the GridView, and the getView() method is not even called.

谁能提供帮助? 为什么不打字?

增编

dbAdapter = new DBAdapter(this);    
dbAdapter.open();

Cursor c;
c = dbAdapter.fetchPCList();
startManagingCursor(c);     

String[] from = new String[] {};
int[] to = new int[] {};

GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new PCIconAdapter(this, R.layout.pc_icon, c, from, to));

c.close();
dbAdapter.close();

<Adapter>

public class PCIconAdapter extends SimpleCursorAdapter { private final Context mContext; private final int mLayout; private final Cursor mCursor; private final int mPCIDIndex; private final int mClassNameIndex; private final LayoutInflater mLayoutInflater; private final class ViewHolder { public TextView pc_id_view; public TextView clas_name_view; } public PCIconAdapter(Context context, int layout, Cursor c, String[] from, int[] to) { super(context, layout, c, from, to); this.mContext = context; this.mLayout = layout; this.mCursor = c; this.mPCIDIndex = mCursor.getColumnIndex(DBAdapter.KEY_PC_LM_ID); this.mClassNameIndex = mCursor.getColumnIndex(DBAdapter.KEY_PC_CLAS_NAME); this.mLayoutInflater = LayoutInflater.from(mContext); } public View getView(int position, View convertView, ViewGroup parent) { if (mCursor.moveToPosition(position)) { ViewHolder viewHolder; if (convertView == null) { convertView = mLayoutInflater.inflate(mLayout, null); viewHolder = new ViewHolder(); viewHolder.pc_id_view = (TextView) convertView.findViewById(R.id.pc_id); viewHolder.clas_name_view = (TextView) convertView.findViewById(R.id.clas_name); convertView.setTag(viewHolder); } else { viewHolder = (ViewHolder) convertView.getTag(); } String pc_id = mCursor.getString(mPCIDIndex); String clas_name = mCursor.getString(mClassNameIndex); viewHolder.pc_id_view.setText(pc_id); viewHolder.clas_name_view.setText(clas_name); } return convertView; } }

Answer 1

如果是,

c.close();
dbAdapter.close();

......

因此,我为什么要关闭这个 cur子?

Answer 2

我有同样的问题。我正在使用阿雷拉Adapter,然后我改成了一个简单的CursorAdapter,但是它没有显示屏幕上的任何东西。

I 删除

c.close();
dbAdapter.close();

如今,它的工作罚款。

Answer 3

because CursorAdapter does not have getView method . it have newView method . so extend SimpleCursorAdapter and overRide newWiev and other methods like

public class ContactListCursorAdapter extends SimpleCursorAdapter implements Filterable {

    private Context context;

    private int layout;

    public ContactListCursorAdapter (Context context, int layout, Cursor c, String[] from, int[] to) {
        super(context, layout, c, from, to);
        this.context = context;
        this.layout = layout;
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {

        Cursor c = getCursor();

        final LayoutInflater inflater = LayoutInflater.from(context);
        View v = inflater.inflate(layout, parent, false);

        int nameCol = c.getColumnIndex(People.NAME);

        String name = c.getString(nameCol);

        /**
         * Next set the name of the entry.
         */     
        TextView name_text = (TextView) v.findViewById(R.id.name_entry);
        if (name_text != null) {
            name_text.setText(name);
        }

        return v;
    }

    @Override
    public void bindView(View v, Context context, Cursor c) {

        int nameCol = c.getColumnIndex(People.NAME);

        String name = c.getString(nameCol);

        /**
         * Next set the name of the entry.
         */     
        TextView name_text = (TextView) v.findViewById(R.id.name_entry);
        if (name_text != null) {
            name_text.setText(name);
        }
    }

    @Override
    public Cursor runQueryOnBackgroundThread(CharSequence constraint) {
        if (getFilterQueryProvider() != null) { return getFilterQueryProvider().runQuery(constraint); }

        StringBuilder buffer = null;
        String[] args = null;
        if (constraint != null) {
            buffer = new StringBuilder();
            buffer.append("UPPER(");
            buffer.append(People.NAME);
            buffer.append(") GLOB ?");
            args = new String[] { constraint.toString().toUpperCase() + "*" };
        }

        return context.getContentResolver().query(People.CONTENT_URI, null,
                buffer == null ? null : buffer.toString(), args, People.NAME + " ASC");
    }
}

Answer 4

你的列名阵列和观点阵列都是空的。因此,从来就永远不会出现对绘图的看法。这可能是因为你在听取意见时没有退步。

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