我的自定义适配器中的 onCreateViewHolder 函数出现了一个奇怪的异常。可能是因为 getItemViewType 函数按预期返回不同的值。
这是 getItemViewType 函数的样子:
private static final int TYPE_HEADER = 0;
private static final int TYPE_ITEM = 1;
@Override
public int getItemViewType(int position) {
if (position == 0)
return TYPE_HEADER;
return TYPE_ITEM;
}
这是 onCreateViewHolder 函数的样子:
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_HEADER) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_groups, null);
return new HeaderHolder(view);
} else if(viewType == TYPE_ITEM) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.explore_group_row, null);
return new ItemHolder(view);
}
throw new RuntimeException("there is no type that matches the type " + viewType + " make sure your using types correctly");
}
另外，我无法重现这个问题，不知道它是怎么发生的。
我在 this thread 中看到了类似的问题，但没有解决方案。
在这里您可以看到 crashlytics 的异常:
Fatal Exception: java.lang.RuntimeException: there is no type that matches the type 6 make sure your using types correctly
at com.example.eliran.forum.GroupsFragment$GroupsAdapter.onCreateViewHolder(GroupsFragment.java:72)
at androidx.recyclerview.widget.RecyclerView$Adapter.createViewHolder(RecyclerView.java:5)
at androidx.recyclerview.widget.RecyclerView$Recycler.a(RecyclerView.java:295)
at androidx.recyclerview.widget.GapWorker.prefetchPositionWithDeadline(GapWorker.java:14)
at androidx.recyclerview.widget.GapWorker.flushTaskWithDeadline(GapWorker.java:15)
at androidx.recyclerview.widget.GapWorker.flushTasksWithDeadline(GapWorker.java:22)
at androidx.recyclerview.widget.GapWorker.a(GapWorker.java:3)
at androidx.recyclerview.widget.GapWorker.run(GapWorker.java:71)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7078)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965)
private class GroupsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static final int TYPE_HEADER = 0;
private static final int TYPE_ITEM = 1;
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_HEADER) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_groups, null);
return new HeaderHolder(view);
} else if(viewType == TYPE_ITEM) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.explore_group_row, null);
return new ItemHolder(view);
}
throw new RuntimeException("there is no type that matches the type " + viewType + " make sure your using types correctly");
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int i) {
if (holder instanceof ItemHolder) {
ItemHolder theHolder = (ItemHolder) holder;
Group group = groups.get(i - 1);
theHolder.title.setText(group.getTitle());
theHolder.description.setText(group.getDescription());
if(group.getImage() != null) {
Picasso.get()
.load(group.getImage())
.fit()
.into(theHolder.image);
} else {
Picasso.get()
.load(R.drawable.profile_picture_holder)
.fit()
.into(theHolder.image);
}
} else if (holder instanceof HeaderHolder){
HeaderHolder theHolder = (HeaderHolder) holder;
if (showMyGroupsPb) {
theHolder.myGroupsPb.setVisibility(View.VISIBLE);
theHolder.myGroupSectionHeader.setOnBtnListener(null);
} else {
theHolder.myGroupsPb.setVisibility(View.GONE);
theHolder.myGroupSectionHeader.setOnBtnListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(rootView.getContext(), MyGroupsActivity.class);
intent.putExtra("groups", myGroups);
startActivityForResult(intent, TheFinals.JOIN_LEAVE_GROUP_CODE);
}
});
}
}
}
@Override
public int getItemViewType(int position) {
if (position == 0)
return TYPE_HEADER;
return TYPE_ITEM;
}
@Override
public int getItemCount() {
return groups.size() + 1;
}
class HeaderHolder extends RecyclerView.ViewHolder {
private ProgressBar myGroupsPb;
private SectionHeader myGroupSectionHeader;
public HeaderHolder(View view) {
super(view);
myGroupsRv = view.findViewById(R.id.groupsRecyclerView);
myGroupsPb = view.findViewById(R.id.pb);
LinearLayoutManager horizontalLayoutManager
= new LinearLayoutManager(rootView.getContext(), LinearLayoutManager.HORIZONTAL, false);
myGroupsRv.setLayoutManager(horizontalLayoutManager);
myGroupsRv.setAdapter(myGroupAdapter);
myGroupSectionHeader = view.findViewById(R.id.myGroupSectionHeader);
}
}
class ItemHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
protected TextView title;
protected ImageView image;
protected TextView description;
public ItemHolder(View view) {
super(view);
this.title = view.findViewById(R.id.title);
this.image = view.findViewById(R.id.image);
this.description = view.findViewById(R.id.description);
view.setOnClickListener(this);
}
@Override
public void onClick(View view) {
int itemPosition = groupsRecyclerView.getChildLayoutPosition(view) - 1;
selectedGroupIndex = itemPosition;
Intent intent = new Intent(rootView.getContext(), GroupActivity.class);
intent.putExtra("group", groups.get(itemPosition));
startActivityForResult(intent, TheFinals.JOIN_LEAVE_GROUP_CODE);
}
}
}
最佳答案
你把 if 条件写错了。您需要完成 if 条件，如下所示:
private static final int TYPE_HEADER = 0;
private static final int TYPE_ITEM = 1;
@Override
public int getItemViewType(int position) {
if (position == 0){
return TYPE_HEADER;
}
return TYPE_ITEM;
}
关于java - RecyclerView 适配器 - onCreateViewHolder 接收未知的 viewType，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/63518500/