android - 我正在尝试将 header 设置为 staggardGridLayoutManeger

Question

我正在尝试将 header 设置为 staggardGridLayoutManeger 我有来自此网址的代码 https://github.com/willblaschko/header-footer-recycler-view .此代码包含所有类型布局的页眉和页脚。任何人都可以帮助只为 staggardGridLayout 设置适配器这是示例中的代码

enter code here
public class RecyclerViewHeaderFooterAdapter extends RecyclerView.Adapter {

public static final int TYPE_MANAGER_OTHER = 0;
public static final int TYPE_MANAGER_LINEAR = 1;
public static final int TYPE_MANAGER_GRID = 2;
public static final int TYPE_MANAGER_STAGGERED_GRID = 3;


public static final int TYPE_HEADER = 7898;
public static final int TYPE_FOOTER = 7899;

private List<View> mHeaders = new ArrayList<>();
private List<View> mFooters = new ArrayList<>();

private int mManagerType;
private RecyclerView.LayoutManager mManager;
private IRecyclerViewIntermediary mIntermediary;


public RecyclerViewHeaderFooterAdapter(RecyclerView.LayoutManager manager, IRecyclerViewIntermediary intermediary){
    setManager(manager);
    this.mIntermediary = intermediary;
}

public void setLayoutManager(RecyclerView.LayoutManager manager){
    setManager(manager);
}

private void setManager(RecyclerView.LayoutManager manager){
    mManager = manager;
    if(mManager instanceof GridLayoutManager){
        mManagerType = TYPE_MANAGER_GRID;
        ((GridLayoutManager) mManager).setSpanSizeLookup(mSpanSizeLookup);
    }else if(mManager instanceof LinearLayoutManager){
        mManagerType = TYPE_MANAGER_LINEAR;
    }else if(mManager instanceof StaggeredGridLayoutManager){
        mManagerType = TYPE_MANAGER_STAGGERED_GRID;
        ((StaggeredGridLayoutManager) mManager).setGapStrategy(StaggeredGridLayoutManager.GAP_HANDLING_MOVE_ITEMS_BETWEEN_SPANS);
    }else{
        mManagerType = TYPE_MANAGER_OTHER;
    }
}

public int getManagerType(){
    return mManagerType;
}

public int getGridSpan(int position){
    if(isHeader(position) || isFooter(position)){
        return getSpan();
    }
    position -= mHeaders.size();
    if(mIntermediary.getItem(position) instanceof IGridItem){
        return ((IGridItem) mIntermediary.getItem(position)).getGridSpan();
    }
    return 1;
}

private int getSpan(){
    if(mManager instanceof GridLayoutManager){
        return ((GridLayoutManager) mManager).getSpanCount();
    }else if(mManager instanceof StaggeredGridLayoutManager){
        return ((StaggeredGridLayoutManager) mManager).getSpanCount();
    }
    return 1;
}

private GridLayoutManager.SpanSizeLookup mSpanSizeLookup = new GridLayoutManager.SpanSizeLookup(){
    @Override
    public int getSpanSize(int position) {
        return getGridSpan(position);
    }
};


@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int type) {
    //if our position is one of our items (this comes from getItemViewType(int position) below)
    if(type !=  TYPE_HEADER && type != TYPE_FOOTER) {
        return mIntermediary.getViewHolder(viewGroup, type);
        //else we have a header/footer
    }else{
        //create a new framelayout, or inflate from a resource
        FrameLayout frameLayout = new FrameLayout(viewGroup.getContext());
        //make sure it fills the space
        frameLayout.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
        return new HeaderFooterViewHolder(frameLayout);
    }
}

@Override
public void onBindViewHolder(final RecyclerView.ViewHolder vh, int position) {
    //check what type of view our position is
    if(isHeader(position)){
        View v = mHeaders.get(position);
        //add our view to a header view and display it
        prepareHeaderFooter((HeaderFooterViewHolder) vh, v);
    }else if(isFooter(position)){
        View v = mFooters.get(position-mIntermediary.getItemCount()-mHeaders.size());
        //add our view to a footer view and display it
        prepareHeaderFooter((HeaderFooterViewHolder) vh, v);
    }else {
        //it's one of our items, display as required
        mIntermediary.populateViewHolder(vh, position-mHeaders.size());
    }
}

private void prepareHeaderFooter(HeaderFooterViewHolder vh, View view){

    //if it's a staggered grid, span the whole layout
    if(mManagerType == TYPE_MANAGER_STAGGERED_GRID){
        StaggeredGridLayoutManager.LayoutParams layoutParams = new StaggeredGridLayoutManager.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        layoutParams.setFullSpan(true);
        vh.itemView.setLayoutParams(layoutParams);
    }

    //if the view already belongs to another layout, remove it
    if(view.getParent() != null){
        ((ViewGroup)view.getParent()).removeView(view);
    }

    //empty out our FrameLayout and replace with our header/footer
    vh.base.removeAllViews();
    vh.base.addView(view);

}

private boolean isHeader(int position){
    return(position < mHeaders.size());
}
private boolean isFooter(int position){
    return(position >= mHeaders.size() + mIntermediary.getItemCount());
}



@Override
public int getItemCount() {
    return mHeaders.size() + mIntermediary.getItemCount() + mFooters.size();
}

@Override
public int getItemViewType(int position) {
    //check what type our position is, based on the assumption that the order is headers > items > footers
    if(isHeader(position)){
        return TYPE_HEADER;
    }else if(isFooter(position)){
        return TYPE_FOOTER;
    }
    int type = mIntermediary.getItemViewType(position);
    if(type == TYPE_HEADER || type == TYPE_FOOTER){
        throw new IllegalArgumentException("Item type cannot equal "+TYPE_HEADER+" or "+TYPE_FOOTER);
    }
    return type;
}

//add a header to the adapter
public void addHeader(View header){
    if(!mHeaders.contains(header)){
        mHeaders.add(header);
        //animate
        notifyItemInserted(mHeaders.size()-1);
    }
}

//remove a header from the adapter
public void removeHeader(View header){
    if(mHeaders.contains(header)){
        //animate
        notifyItemRemoved(mHeaders.indexOf(header));
        mHeaders.remove(header);
    }
}

//add a footer to the adapter
public void addFooter(View footer){
    if(!mFooters.contains(footer)){
        mFooters.add(footer);
        //animate
        notifyItemInserted(mHeaders.size()+mIntermediary.getItemCount()+mFooters.size()-1);
    }
}

//remove a footer from the adapter
public void removeFooter(View footer){
    if(mFooters.contains(footer)) {
        //animate
        notifyItemRemoved(mHeaders.size()+mIntermediary.getItemCount()+mFooters.indexOf(footer));
        mFooters.remove(footer);
    }
}

//our header/footer RecyclerView.ViewHolder is just a FrameLayout
public static class HeaderFooterViewHolder extends RecyclerView.ViewHolder{
    FrameLayout base;
    public HeaderFooterViewHolder(View itemView) {
        super(itemView);
        base = (FrameLayout) itemView;
    }
}

Answer 1

我解决了这个问题，为我的 header 适配器添加了一个新类型。看这个例子:https://stackoverflow.com/a/26573338/1949163 .

之后，为了使标题跨越所有列，我创建了一个新的 LayoutParams 并在适配器实现中将 full span 设置为 true:

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    if (holder instanceof CommonItemViewHolder) {
        ...
    } else if (holder instanceof HeaderViewHolder) {
        ...
        StaggeredGridLayoutManager.LayoutParams layoutParams = new StaggeredGridLayoutManager.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        layoutParams.setFullSpan(true);
        holder.itemView.setLayoutParams(layoutParams);
    }
}