Question

我的回收卡中有一个按钮，需要显示popupMenu

但是，只要用户点击此按钮，就不会显示popupMenu。即使我在menuOptionsButton.Click动作中设置了一个断点，它也没有击中。

XML中的ImageButton

<ImageButton
    android:id="@+id/MoreSettings"
    android:layout_width="40dp"
    android:layout_height="40dp"
    android:layout_alignParentRight="true"
    android:src="@drawable/ic_more_black_24dp" />

RecyclerViewAdapter.cs

public class RecyclerAdapter : MvxRecyclerAdapter
{
  private readonly FragmentActivity _activity;

  public RecyclerAdapter(IMvxAndroidBindingContext bindingContext, FragmentActivity activity)
        : base(bindingContext)
  {
    _activity = activity;
  }

  public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
  {
    base.OnBindViewHolder(holder, position);
    var view = holder.ItemView;
    var menuOptionsButton = view.FindViewById<ImageButton>(Resource.Id.MoreSettings);
    menuOptionsButton.Click += (s, e) =>
     {
         var popup = new PopupMenu(_activity, menuOptionsButton );
         popup.MenuInflater.Inflate(Resource.Menu.menu,popup.Menu);
         popup.Show();
     };
  }
}

如果我没有将popupMenu放入点击操作中，则recyclerview中的每个项目都会显示popupMenu，但我希望点击操作以显示popUpMenu。

public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
    base.OnBindViewHolder(holder, position);
    var view = holder.ItemView;
    var menuOptionsButton = view.FindViewById<ImageButton>(Resource.Id.MoreSettings);
    var popup = new PopupMenu(_activity, menuOptionsButton );
    popup.MenuInflater.Inflate(Resource.Menu.menu,popup.Menu);
    popup.Show();
}

更新：

Activity.cs

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
    var ignored = base.OnCreateView(inflater, container, savedInstanceState);
    var view = this.BindingInflate(Resource.Layout.AView, null);   
    HasOptionsMenu = true;
    toolbar = ((MainView)Activity).SupportActionBar;   
    var recyclerView = view.FindViewById<MvxRecyclerView>(Resource.Id.ARecyclerView);
    if (recyclerView != null)
    {
        recyclerView.HasFixedSize = true;
        recyclerView.Adapter = new RecyclerAdapter((IMvxAndroidBindingContext)BindingContext, Activity);
        var layoutManager = new LinearLayoutManager(Activity);
        recyclerView.SetLayoutManager(layoutManager);
      }
    return view;
}

Answer 1

在RecyclerView.Adapter代码中，在OnBindViewHolder方法中添加Click委托时应该小心。如果您添加为C＃匿名函数，则每次View都显示新的委托时，将添加，而不是设置。

首先，您应该将此行放在ViewHolder构造函数方法中：

this.menuOptionsButton = view.FindViewById<ImageButton>(Resource.Id.MoreSettings);

然后，

public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
    base.OnBindViewHolder(holder, position);
    var optionsButton = ((YourHolder)holder).menuOptionsButton;

    // This avoids adding a Click event more than once
    optionsButton.Click -= this.PopupShow;
    optionsButton.Click += this.PopupShow;
}

private void PopupShow(object sender, EventArgs e)
{
    Toast.MakeText(this.context, "Button clicked", ToastLength.Short).Show();
    var popup = new PopupMenu(_activity, menuOptionsButton );
    popup.MenuInflater.Inflate(Resource.Menu.menu,popup.Menu);
    popup.Show();
}

RecylerView按钮不会触发

1 个答案: