Question

我试图用Mosby实现MVP Android View（不是活动或片段），但是当在Android适配器中使用视图并在onBindViewHolder中访问它时，此时不会初始化演示者。看起来onAttachWindow直到onBindViewHolder完成后才被调用，因为演示者是Null。这是我创建的抽象类。

public abstract class MvpImageView<V extends MvpView, P extends MvpPresenter<V>>
    extends AppCompatImageView implements MvpView, ViewGroupDelegateCallback<V, P> {

  protected P presenter;
  protected ViewGroupMvpDelegate<V, P> mvpDelegate;
  private boolean retainInstance = false;

  public MvpImageView(Context context) {
    super(context);
  }

  public MvpImageView(Context context, AttributeSet attrs) {
    super(context, attrs);
  }

  public MvpImageView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
  }

  /**
   * Get the mvp delegate. This is internally used for creating presenter, attaching and detaching
   * view from presenter etc.
   *
   * <p><b>Please note that only one instance of mvp delegate should be used per android.view.View
   * instance</b>.
   * </p>
   *
   * <p>
   * Only override this method if you really know what you are doing.
   * </p>
   *
   * @return {@link ViewGroupMvpDelegate}
   */
  @NonNull protected ViewGroupMvpDelegate<V, P> getMvpDelegate() {
    if (mvpDelegate == null) {
      mvpDelegate = new ViewGroupMvpDelegateImpl<>(this, this, true);
    }

    return mvpDelegate;
  }

  @Override protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    Log.d(getClass().getName(), "Attaching to Window");
    getMvpDelegate().onAttachedToWindow();
  }

  @Override protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    Log.d(getClass().getName(), "Detaching from Window");
    getMvpDelegate().onDetachedFromWindow();
  }

  @SuppressLint("MissingSuperCall") @Override protected Parcelable onSaveInstanceState() {
    return getMvpDelegate().onSaveInstanceState();
  }

  @SuppressLint("MissingSuperCall") @Override
  protected void onRestoreInstanceState(Parcelable state) {
    getMvpDelegate().onRestoreInstanceState(state);
  }

  /**
   * Instantiate a presenter instance
   *
   * @return The {@link MvpPresenter} for this view
   */
  public abstract P createPresenter();

  @Override public P getPresenter() {
    return presenter;
  }

  @Override public void setPresenter(P presenter) {
    this.presenter = presenter;
  }

  @Override public V getMvpView() {
    return (V) this;
  }

  @Override public final Parcelable superOnSaveInstanceState() {
    return super.onSaveInstanceState();
  }

  @Override public final void superOnRestoreInstanceState(Parcelable state) {
    super.onRestoreInstanceState(state);
  }
}

这是基于MvpLinearLayout实现。我过去使用过另一个名为Moxy的MVP库，它有onCreate和onAttachToWindow的委托方法。

我可以在构造函数中添加一个调用getMvpDelegate（）。onAttachWindow的初始化例程，但这看起来更像是一个hack而不是其他任何东西。在onBindViewHolder和RecyclerView中使用时如何使其工作的任何想法？

Answer 1

不要在适配器中使用MVP。它只会使事情变得复杂和繁琐。

示例：如果Presenter也可以回收，可以回收Views / ViewHolder吗？如果是，您如何实现这一点并确保内部Presenter是新鲜的？如何在滚动时重新连接Presenter进行查看？如果您的AdapterSet发生了变化怎么办？屏幕方向改变怎么样？

根本不要那样做。

使用Mosby实现非ViewGroup MVP Android视图

1 个答案: