Question

在我的应用程序中，我使用的是RecyclerView，当用户向下滚动时，应该继续加载图像。但这让我遇到了一个我无法解决的问题。基本上，我说

        loadPhotos.LoadMoreItems(3);

这意味着，首先加载3张照片。一旦到达某个点（通过滚动）继续加载另外3张图片（组成一行）：

        var onScrollListener = new XamarinRecyclerViewOnScrollListener(mLayoutManager);
        onScrollListener.LoadMoreEvent += (object sender, EventArgs e) => 
        {
            int oldCount = loadPhotos.pictures.Count;
            loadPhotos.LoadMoreItems(3);
            mAdapter.NotifyItemRangeChanged(oldCount - 1, loadPhotos.pictures.Count);
        };

如果我只加载3张照片，首先，手机会加载3张照片，然后是一瞬间，它会加载下一行，因为已达到位置。事实上，这确实有效，但如果我开始滚动，我会收到此错误：

 “cannot call this method while RecyclerView is computing a layout or scrolling”

在这一行：

mAdapter.NotifyItemRangeChanged(oldCount - 1, loadPhotos.pictures.Count);

另一个有趣的事实是，我可以在小型手机上使用它，但屏幕较大的手机（三星s8）会很快崩溃。

所以，我真的很困惑如何做到这一切。就像额外信息一样，这是我的整个活动：

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        SetContentView(Resource.Layout.Fragment_Gallery);


        galleryType = Intent.GetIntExtra("galleryType", 0);

        picturesinarow = Intent.GetIntExtra("picturesinarow", 1);

        recyclerLayout = Intent.GetIntExtra("recyclerLaoyut", (int)RecyclerLayout.Multiplepics);

        hasHeader = Intent.GetBooleanExtra("hasHeader", false);

        // Instantiate the photo album:
        loadPhotos = new BookOfLife.CustomRecyclerView.ReloadAdapter(this.galleryType);
        loadPhotos.LoadMoreItems(3);//(Constants.ITEMSPERPAGE);

        // Get our RecyclerView layout:
        mRecyclerView = FindViewById<RecyclerView>(Resource.Id.recyclerView);



        //............................................................
        // Layout Manager Setup:

        // Use the built-in linear layout manager:
        //mLayoutManager = new LinearLayoutManager(this);

        // Or use the built-in grid layout manager (two horizontal rows):
        mLayoutManager = new GridLayoutManager(this, this.picturesinarow, GridLayoutManager.Vertical, false);

        // Plug the layout manager into the RecyclerView:
        mRecyclerView.SetLayoutManager(mLayoutManager);

        //............................................................
        // Adapter Setup:

        // Create an adapter for the RecyclerView, and pass it the
        // data set (the photo album) to manage:
        mAdapter = new PhotoAlbumAdapter(loadPhotos, this.picturesinarow, (RecyclerLayout)this.recyclerLayout, this.hasHeader);

        // Register the item click handler (below) with the adapter:
        mAdapter.ItemClick += OnItemClick;

        // Plug the adapter into the RecyclerView:
        mRecyclerView.SetAdapter(mAdapter);
        //.........................................................................

        //Set Spanwidth for GridHeader
        mLayoutManager.SetSpanSizeLookup(new GridViewSpansizeLookup(mAdapter, mLayoutManager));


        // On Scroll Listener
        var onScrollListener = new XamarinRecyclerViewOnScrollListener(mLayoutManager);
        onScrollListener.LoadMoreEvent += (object sender, EventArgs e) => 
        {
            int oldCount = loadPhotos.pictures.Count;
            loadPhotos.LoadMoreItems(3);//(Constants.LOADNEXTITEMSTHRESHHOLD);


            mAdapter.NotifyItemRangeChanged(oldCount - 1, loadPhotos.pictures.Count);
        };

        mRecyclerView.AddOnScrollListener(onScrollListener);
    }

希望，你们可以帮助我在这里：）

Answer 1

好吧，我似乎找到了一个简单的解决办法：

           if(!mRecyclerView.IsComputingLayout)
            mAdapter.NotifyItemRangeChanged(oldCount - 1, loadPhotos.pictures.Count);

我只需要确保，我总是提供照片，以便recview会滚动。

当滚动和重新加载同时发生时，RecyclerView崩溃

1 个答案: