SimpleCursorAdapter仅加载可见项

Question

我使用自定义适配器，它扩展了SimpleCursorAdadapter。列表视图中的所有项目都可以在屏幕上看到所有工作正常，但如果项目数量超过屏幕中可以包含的项目位置重复（例如我点击第一项，第一项隐藏项目也被激活）

public class CustomAdapter extends SimpleCursorAdapter {

    private Context mContext;
    private Context appContext;
    private int layout;
    private Cursor cursor;
    private final LayoutInflater inflater;
    DB db;

    public CustomAdapter(Context context, int layout, Cursor c,String[] from,int[] to) {
        super(context,layout,c,from,to);
        this.layout=layout;
        this.mContext = context;
        this.inflater=LayoutInflater.from(context);
        this.cursor=c;
    }

    @Override
    public View newView (Context context, Cursor cursor, ViewGroup parent) {
            return inflater.inflate(layout, null);
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        super.bindView(view, context, cursor);
        ImageView marker = (ImageView)view.findViewById(R.id.item_productiviry_img);
        TextView prod_tv = (TextView)view.findViewById(R.id.tvMarker);
        if(prod_tv.getText().length() == 10)marker.setImageResource(R.drawable.productive);
        if(prod_tv.getText().length() == 7)marker.setImageResource(R.drawable.neutral);
        if(prod_tv.getText().length() == 12)marker.setImageResource(R.drawable.unproductive);
    }
}