Question

我正在尝试制作图库应用。在显示图像时，我使用了GridLayoutManager来显示图像，并且在显示Header视图时我还增加了span列（通过使用setSpanSizeLookup）。但是当我滚动浏览大约500张图像的列表时，它滚动似乎有点滞后。如果我删除setSpanSizeookup代码比它顺利工作。请告诉我如何解决这个问题。

这是我的活动onCreate方法，

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_select_image);

    getImagesPath(this);

    send = findViewById(R.id.send);
    dialog = new ProgressDialog(this);
    recyclerView = findViewById(R.id.recycler);
    GridLayoutManager manager = new GridLayoutManager(this, 4, GridLayoutManager.VERTICAL, false);

    manager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {
            switch (adapter.getItemViewType(position)) {
                case GalleryAdapter.VIEW_TYPE_HEADER:
                    return 4;
                case GalleryAdapter.VIEW_TYPE_ITEM:
                    return 1;
                default:
                    return 1;
            }
        }
    });

    recyclerView.setLayoutManager(manager);
    recyclerView.addItemDecoration(new GridItemDecor(3));
    recyclerView.setHasFixedSize(true);
    recyclerView.setItemViewCacheSize(25);
    recyclerView.setDrawingCacheEnabled(true);
    recyclerView.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
    adapter = new GalleryAdapter(this, imageList);
    recyclerView.setAdapter(adapter);

    dialog.setCanceledOnTouchOutside(false);
    send.setOnClickListener(this);

    deviceName = getDeviceName();
}

这是我的适配器类，

public class GalleryAdapter extends RecyclerView.Adapter<GalleryAdapter.GalleryViewHolder> {

public static final int VIEW_TYPE_HEADER = 2;
public static final int VIEW_TYPE_ITEM = 1;
private Context context;
private ArrayList<String> imageList;
private ArrayList<String> uriList = new ArrayList<>();
private ArrayList<String> selectAllList = new ArrayList<>();
private ArrayList<String> videoList = new ArrayList<>();
private VideoThumbLoader thumbLoader = new VideoThumbLoader();

public GalleryAdapter(Context context, ArrayList<String> imageList) {
    this.context = context;
    this.imageList = imageList;
}

@NonNull
@Override
public GalleryViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view;
    if (viewType == 1)
        view = LayoutInflater.from(context).inflate(R.layout.ly_single_image, parent, false);
    else
        view = LayoutInflater.from(context).inflate(R.layout.ly_single_date, parent, false);

    return new GalleryViewHolder(view, viewType);
}

@Override
public void onBindViewHolder(@NonNull GalleryViewHolder holder, int position) {
    switch (holder.getItemViewType()) {
        case VIEW_TYPE_ITEM: {
            holder.overlay.setVisibility(uriList.contains(imageList.get(holder.getAdapterPosition())) ? View.VISIBLE : View.GONE);
            holder.video.setVisibility(videoList.contains(imageList.get(holder.getAdapterPosition())) ? View.VISIBLE : View.GONE);

            Glide.with(holder.image.getContext())
                    .clear(holder.image);

            File file = new File(imageList.get(holder.getAdapterPosition()));
            if (getMimeType(file).contains("video")) {
                holder.video.setVisibility(View.VISIBLE);
                videoList.add(imageList.get(holder.getAdapterPosition()));

                holder.image.setTag(imageList.get(holder.getAdapterPosition()));
                thumbLoader.showThumbByAsynctack(imageList.get(holder.getAdapterPosition()), holder.image);
            } else {
                Uri uri = Uri.parse(imageList.get(holder.getAdapterPosition()));
                Glide.with(holder.image.getContext())
                        .load(new File(uri.getPath()))
                        .apply(RequestOptions
                                .centerCropTransform())
                        .thumbnail(1f)
                        .into(holder.image);
            }
        }
        break;

        case VIEW_TYPE_HEADER: {
            holder.date.setText(imageList.get(holder.getAdapterPosition()));

            if (selectAllList.contains(imageList.get(position))) {
                holder.selectAll.setTag(R.drawable.ic_selectall_placeholder);
                holder.selectAll.setBackground(context.getDrawable(R.drawable.ic_selectall_placeholder));
            } else {
                holder.selectAll.setTag(R.drawable.ic_deselectall_placeholder);
                holder.selectAll.setBackground(context.getDrawable(R.drawable.ic_deselectall_placeholder));
            }
        }
        break;
    }
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public int getItemViewType(int position) {
    File file = new File(imageList.get(position));
    if (file.exists())
        return VIEW_TYPE_ITEM;
    else
        return VIEW_TYPE_HEADER;
}

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

这是我的活动布局代码，

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.pixelolio.pixelolio.ui.activity.SelectImageActivity">

<android.support.v7.widget.RecyclerView
    android:id="@+id/recycler"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_above="@+id/layout" />

这是我单张图片的布局，

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">

<ImageView
    android:id="@+id/image"
    android:layout_width="100dp"
    android:layout_height="100dp"/>

这是单个日期（标题）的布局代码，

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center_vertical"
android:layout_margin="10dp">
<TextView
    android:id="@+id/date"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="@dimen/extra_small_text_size"
    android:textColor="@android:color/black"
    android:text="21 Sept"
    android:textStyle="bold"/>

<View
    android:id="@+id/selectAll"
    android:layout_width="20dp"
    android:layout_height="20dp"
    android:background="@drawable/ic_deselectall_placeholder"
    android:padding="5dp"
    android:layout_marginStart="10dp"/>

Answer 1

尝试更改包含此表单中的RecyclerView的布局结构

<ScrollView >
<LinearLayout >
   <View > <!-- upper content -->
        <RecyclerView > <!-- with custom layoutmanager -->
</LinearLayout >

当滚动时出现一点延迟时，我会使用这种结构。

GridView中的标题视图与Reyclerview导致滞后

1 个答案: