我尝试关注如何使用自定义LinearLayoutManager的{{3}}，但我的嵌套RecyclerView根本没有显示。
RecyclerView detailsRecyclerView = (RecyclerView) dialog.findViewById(R.id.category_dish_dialog_recycler_view);
detailsRecyclerView.setHasFixedSize(true);
LinearLayoutManager layoutManager = new LinearLayoutManager(CategoryActivity.this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
detailsRecyclerView.setLayoutManager(layoutManager);
DishDetailsAdapter detailsAdapter = new DishDetailsAdapter(dish.getDishOptions(), CategoryActivity.this);
detailsRecyclerView.setAdapter(detailsAdapter);
detailsAdapter.notifyDataSetChanged();
请注意，子/嵌套的RecyclerView位于OptionsViewHolder：
public class DishDetailsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private List<DishOption> options;
private Context context;
private SharedData sharedData = SharedData.getInstance();
public DishDetailsAdapter(List<DishOption> detailsList, Context parentContext) {
options = detailsList;
context = parentContext;
sharedData.setMainFont(context);
sharedData.setSecondaryFont(context);
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View view = inflater.inflate(R.layout.category_dish_dialog_option, parent, false);
RecyclerView.ViewHolder viewHolder = new OptionsViewHolder(view);
return viewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
DishOption dishOption = options.get(position);
OptionsViewHolder vh = (OptionsViewHolder) holder;
vh.optionName.setText(dishOption.getTitle());
vh.optionName.setTypeface(sharedData.getSecondaryFont());
List<DishOptionItem> dishOptionItems = dishOption.getItems();
ItemsAdapter itemsAdapter = new ItemsAdapter(dishOptionItems, context);
//NOTICE CHILD/NESTED RECYCLER VIEW HERE!!!!!!!!!!!!!!!!!!!!!!!
vh.nestedRecyclerView.setAdapter(itemsAdapter);
itemsAdapter.notifyDataSetChanged();
LinearLayoutManager layoutManager = new NestedLinearLayoutManager(context, LinearLayoutManager.VERTICAL, false);
vh.nestedRecyclerView.setLayoutManager(layoutManager);
}
@Override
public int getItemCount() {
return options.size();
}
/**
* View holders for dish options Options
*/
public class OptionsViewHolder extends RecyclerView.ViewHolder {
private TextView optionName;
private RecyclerView nestedRecyclerView;
public OptionsViewHolder(View itemView) {
super(itemView);
optionName = (TextView) itemView.findViewById(R.id.dish_dialog_option_title);
nestedRecyclerView = (RecyclerView) itemView.findViewById(R.id.category_nested_recycler_view);
}
}
}
public class ItemsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private List<DishOptionItem> items;
private Context context;
private SharedData sharedData = SharedData.getInstance();
public ItemsAdapter(List<DishOptionItem> itemsList, Context parentParentContext) {
items = itemsList;
context = parentParentContext;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View view = inflater.inflate(R.layout.category_dish_dialog_item, parent, false);
RecyclerView.ViewHolder viewHolder = new ItemViewHolder(view);
return viewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
DishOptionItem item = items.get(position);
ItemViewHolder iVH = (ItemViewHolder) holder;
iVH.itemName.setText(item.getName());
}
@Override
public int getItemCount() {
return items.size();
}
/**
* View holders for dish options Items
*/
public class ItemViewHolder extends RecyclerView.ViewHolder {
private TextView itemName;
private TextView itemPrice;
public ItemViewHolder(View itemView) {
super(itemView);
itemName = (TextView) itemView.findViewById(R.id.dish_dialog_item_name);
//itemPrice = (TextView) itemView.findViewById(R.id.dish_dialog_item_price);
}
}
}
public class NestedLinearLayoutManager extends LinearLayoutManager {
public NestedLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
super(context, orientation, reverseLayout);
}
private int[] mMeasuredDimension = new int[2];
@Override
public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,
int widthSpec, int heightSpec) {
final int widthMode = View.MeasureSpec.getMode(widthSpec);
final int heightMode = View.MeasureSpec.getMode(heightSpec);
final int widthSize = View.MeasureSpec.getSize(widthSpec);
final int heightSize = View.MeasureSpec.getSize(heightSpec);
int width = 0;
int height = 0;
for (int i = 0; i < getItemCount(); i++) {
measureScrapChild(recycler, i,
View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
mMeasuredDimension);
if (getOrientation() == HORIZONTAL) {
width = width + mMeasuredDimension[0];
if (i == 0) {
height = mMeasuredDimension[1];
}
} else {
height = height + mMeasuredDimension[1];
if (i == 0) {
width = mMeasuredDimension[0];
}
}
}
// If child view is more than screen size, there is no need to make it wrap content. We can use original onMeasure() so we can scroll view.
if (height < heightSize && width < widthSize) {
switch (widthMode) {
case View.MeasureSpec.EXACTLY:
width = widthSize;
case View.MeasureSpec.AT_MOST:
case View.MeasureSpec.UNSPECIFIED:
}
switch (heightMode) {
case View.MeasureSpec.EXACTLY:
height = heightSize;
case View.MeasureSpec.AT_MOST:
case View.MeasureSpec.UNSPECIFIED:
}
setMeasuredDimension(width, height);
} else {
super.onMeasure(recycler, state, widthSpec, heightSpec);
}
}
private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
int heightSpec, int[] measuredDimension) {
View view = recycler.getViewForPosition(position);
// For adding Item Decor Insets to view
super.measureChildWithMargins(view, 0, 0);
if (view != null) {
RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
getPaddingLeft() + getPaddingRight() + getDecoratedLeft(view) + getDecoratedRight(view), p.width);
int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
getPaddingTop() + getPaddingBottom() + getPaddingBottom() + getDecoratedBottom(view) , p.height);
view.measure(childWidthSpec, childHeightSpec);
// Get decorated measurements
measuredDimension[0] = getDecoratedMeasuredWidth(view) + p.leftMargin + p.rightMargin;
measuredDimension[1] = getDecoratedMeasuredHeight(view) + p.bottomMargin + p.topMargin;
recycler.recycleView(view);
}
}
}
如果有人认为他们需要查看xml布局文件，我可以在这里发布。请帮助我不知道还有什么可以尝试。