Question

在我的应用中，我有一个 ListView ，可显示照片，标题和说明。但是当我滚动ListView时，即使关闭应用程序也会变慢。每次滚动时ListView都会加载元素，这就是应用程序崩溃的原因。

有人可以帮我做一个有效的ListView吗？

这是我的代码：

public class PropiedadCursorAdapter extends CursorAdapter{

  private LayoutInflater mLayoutInflater;
  private Context ctx;
  private  Cursor miCursor;
  private int layout;
  private int casaIndex;
  private int tituloIndex;
  private int ubicacionIndex;

  private PropiedadDbAdapter dbAdapter =null;

  private  class ViewHolder {

    ImageView ivCasa;
    TextView tvTitulo;
    TextView tvUbicacion;

    ViewHolder(View v) {
      tvTitulo = (TextView) v.findViewById(R.id.tv_titulo);
      tvUbicacion = (TextView) v.findViewById(R.id.tv_ubicacion);
      ivCasa = (ImageView) v.findViewById(R.id.ivCasa);
    }
  }

  public PropiedadCursorAdapter(Context context, int layout, Cursor c){
    super(context, c);
    this.ctx = context;
    this.miCursor = c;

    mLayoutInflater = LayoutInflater.from(context);

  }

  @Override
  public void bindView(View v, Context context, Cursor c) {
    int icol_ivCasa = c.getColumnIndex(C_COLUMNA_IMAGENES);
    int icol_tvTitulo = c.getColumnIndex(PropiedadDbAdapter.C_COLUMNA_TITULO);
    int icol_tvUbicacion = c.getColumnIndex(PropiedadDbAdapter.C_COLUMNA_DIRECCION);

    String stxtCasa = c.getString(icol_ivCasa);
    String stxtTitulo = c.getString(icol_tvTitulo);
    String stxUbicacion = c.getString(icol_tvUbicacion);

    ViewHolder vh = (ViewHolder)v.getTag();

    Picasso.with(context).load(stxtCasa).into(vh.ivCasa);
    vh.tvTitulo.setText(stxtTitulo);
    vh.tvUbicacion.setText(stxUbicacion);

    Log.d("PropiedadCursor", stxtCasa);
  }

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

    View vView = mLayoutInflater.inflate(R.layout.layout_lista_propiedades, parent, false);
    vView.setTag( new ViewHolder(vView) );
    return vView;
  }    
}

这是我的dbAdapter

public class PropiedadDbAdapter {

public static final String C_TABLAp = "PROPIEDADES";

/**
 * TABLE  PROPIEDADES
 */
public static final String C_COLUMNA_ID = "_id";
public static final String C_COLUMNA_TITULO = "titulo";
public static final String C_COLUMNA_PROPIEDAD = "propiedad";
public static final String C_COLUMNA_CATEGORIA = "categoria";
public static final String C_COLUMNA_COLONIA = "colonia";
public static final String C_COLUMNA_DIRECCION = "direccion";
public static final String C_COLUMNA_COORDENADAS = "coordenadas";
public static final String C_COLUMNA_SUPERFICIE = "superficie";
public static final String C_COLUMNA_RECAMARAS = "recamaras";
public static final String C_COLUMNA_IMAGENES = "imagenes";
public static final String C_COLUMNA_PRECIO = "precio";
public static final String C_COLUMNA_ANTIGUEDAD = "antiguedad";
public static final String C_COLUMNA_FECHA = "fecha";
public static final String C_COLUMNA_ACTUALIZACION= "actualizacion";
public static final String C_COLUMNA_EDO_SYNC= "edo_sync";
public static final String C_COLUMNA_DESCRIPCION = "descripcion";
public static final String C_COLUMNA_USR_PROP_ID= "prop_id";

private Context contexto;
private BienesRaDbHeper mDbHelper;
private SQLiteDatabase mDb;

private String[] columnasP = new String[]{C_COLUMNA_ID, C_COLUMNA_TITULO, C_COLUMNA_PROPIEDAD, C_COLUMNA_CATEGORIA, C_COLUMNA_COLONIA, C_COLUMNA_DIRECCION, C_COLUMNA_COORDENADAS, C_COLUMNA_SUPERFICIE, C_COLUMNA_RECAMARAS, C_COLUMNA_IMAGENES, C_COLUMNA_PRECIO, C_COLUMNA_ANTIGUEDAD, C_COLUMNA_FECHA, C_COLUMNA_ACTUALIZACION, C_COLUMNA_EDO_SYNC, C_COLUMNA_DESCRIPCION, C_COLUMNA_USR_PROP_ID};
private String[] columnaUserPropID = new String[]{C_COLUMNA_USR_PROP_ID};


public PropiedadDbAdapter(Context context)
{
    this.contexto = context;
}

public PropiedadDbAdapter abrir() throws SQLException
{
    mDbHelper = new BienesRaDbHeper(contexto);
    mDb = mDbHelper.getWritableDatabase();
    return this;
}

public void cerrar()
{
    mDbHelper.close();
}

public Cursor getCursor() throws SQLException
{
    Cursor cursor = mDb.query(true, C_TABLAp, columnasP, null, null, null, null, null, null);


    return cursor;
}

public Cursor getRegistro(long id) throws SQLException
{
    Cursor c = mDb.query(true, C_TABLAp, columnasP, C_COLUMNA_ID + "=" + id, null, null, null, null, null);


    if (c != null) {
        c.moveToFirst();
    }
    return c;
}

public long insertPropiedad(ContentValues reg)
{
    if (mDb == null)
        abrir();

    return mDb.insert(C_TABLAp, null, reg);
}

public long update(ContentValues reg)
{
    long result = 0;

    if (mDb == null)
        abrir();

    if (reg.containsKey(C_COLUMNA_ID))
    {
        long id = reg.getAsLong(C_COLUMNA_ID);

        reg.remove(C_COLUMNA_ID);

        result = mDb.update(C_TABLAp, reg, "_id=" + id, null);
    }
    return result;
}
public Cursor getCursor(String filtro) throws SQLException
{
    Cursor c = mDb.query(true, C_TABLAp, columnasP, filtro, null, null, null, null, null);

    return c;   }

public Cursor getIdProp(long id) throws SQLException {

    Cursor c = mDb.query(true, C_TABLAp, columnasP, C_COLUMNA_USR_PROP_ID + "=" + id, null, null,null,null,null );
    if (c != null) {
        c.moveToFirst();
        Log.d("PROPIEDAD", String.valueOf(c));
    }
    return c;
}

public long delete(long id)
{
    if (mDb == null)
        abrir();

    return mDb.delete(C_TABLAp, "_id=" + id, null);
}}

Answer 1

不幸的是我无法评论，但就像你在评论中被告知的那样，你应该使用RecyclerView（除非你的要求包括ListView）。

这是一个RecyclerView适配器的示例，您应该可以很容易地自定义它，因为它与您现有的相似：

public class PropiedadCursorAdapter extends RecyclerView.Adapter<PropiedadCursorAdapter.ViewHolder> {

private Context context;

public SearchAdapter(Context context) {
    super();
    this.context = context;
}

public static class ViewHolder extends RecyclerView.ViewHolder {

    private ImageView ivProfilePic;
    private TextView tvUsername;

    public ViewHolder(View itemView) {
        super(itemView);

        ivProfilePic = (ImageView) itemView.findViewById(R.id.ivProfilePic);
        tvUsername = (TextView) itemView.findViewById(R.id.tvUsername);
    }

}

@Override
public SearchAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

    View v = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.item_search_user, parent, false);

    return new ViewHolder(v);
}

@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
    final User user = users.get(position);

    Glide.with(context)
            .load(user.getProfilePicUrl())
            .centerCrop()
            .crossFade()
            .diskCacheStrategy(DiskCacheStrategy.RESULT)
            .into(holder.ivProfilePic);

    holder.tvUsername.setText(user.getUsername());

}

@Override
public int getItemCount() {
    return users.size();
}
}

带有照片的ListView变慢

1 个答案: