我正在使用firebase数据库ui 3.0.0。它工作正常并加载数据，但问题是，当我滚动recylerview时，它显示空行。
这是我的firebase回收器适配器..
FirebaseRecyclerOptions<PostData> options =
new FirebaseRecyclerOptions.Builder<PostData>()
.setQuery(boardref.child("posts"), PostData.class)
.setLifecycleOwner(this)
.build();
adapter = new FirebaseRecyclerAdapter<PostData, blogviewholder>(options){
@Override
public blogviewholder onCreateViewHolder(ViewGroup parent, int viewType) {
switch (viewType) {
case R.layout.post_row1:
return new blogviewholder(LayoutInflater.from(parent.getContext())
.inflate(R.layout.post_row1, parent, false));
case R.layout.post_row2:
return new blogviewholder(LayoutInflater.from(parent.getContext())
.inflate(R.layout.post_row2, parent, false));
case R.layout.post_row3:
return new blogviewholder(LayoutInflater.from(parent.getContext())
.inflate(R.layout.post_row3, parent, false));
default:
throw new IllegalStateException();
}
}
@Override
protected void onBindViewHolder(blogviewholder viewHolder, int position, PostData model) {
int view=viewHolder.getItemViewType();
switch (view) {
case R.layout.post_row1:
viewHolder.setUser(model.getUid(),getApplicationContext(),model.getTimestamp());
viewHolder.setDesc(model.getDesc());
break;
case R.layout.post_row2:
viewHolder.setUser(model.getUid(),getApplicationContext(),model.getTimestamp());
viewHolder.setDesc(model.getDesc());
viewHolder.setImage(getApplicationContext(),model.getData());
break;
case R.layout.post_row3:
viewHolder.setUser(model.getUid(),getApplicationContext(),model.getTimestamp());
viewHolder.setDesc(model.getDesc());
viewHolder.setFile(model.getData(),model.getName(),getApplicationContext());
break;
}
}
@Override
public int getItemViewType(int position) {
PostData postData=getItem(position);
String str=postData.getType();
switch (str) {
case "text":
return R.layout.post_row1;
case "file":
return R.layout.post_row3;
case "image":
return R.layout.post_row2;
}
return position;
}
@Override
public void onDataChanged() {
super.onDataChanged();
adapter.notifyDataSetChanged();
}
};
recyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(BoardDetail.this);
mLayoutManager.setReverseLayout(true);
mLayoutManager.setStackFromEnd(true);
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.addItemDecoration(
new DividerItemDecoration(ContextCompat.getDrawable(getApplicationContext(),
R.drawable.item_decorator)));
recyclerView.setAdapter(adapter);
这是我的博客视图持有者类
private static class blogviewholder extends RecyclerView.ViewHolder{
View mView;
public blogviewholder(View itemView) {
super(itemView);
mView=itemView;
}
public void setUser(String uid, final Context ctx, long timestamp) {
final TextView textView=(TextView) mView.findViewById(R.id.user_name);
final TextView date=(TextView) mView.findViewById(R.id.date);
final ImageView user_image=(ImageView) mView.findViewById(R.id.user_img);
String str=convertTime(timestamp);
date.setText(str);
DatabaseReference mref=FirebaseDatabase.getInstance().getReference("users/"+uid);
mref.keepSynced(true);
mref.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()){
String name=dataSnapshot.child("name").getValue().toString();
textView.setText(name);
final String image=dataSnapshot.child("profile_image").getValue().toString();
Picasso.with(ctx)
.load(image)
.networkPolicy(NetworkPolicy.OFFLINE)
.into(user_image,new Callback() {
@Override
public void onSuccess() {
}
@Override
public void onError() {
//Try again online if cache failed
Picasso.with(ctx).load(image).into((user_image));
}
});
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
public void setDesc(String desc) {
TextView mdesc=(TextView) mView.findViewById(R.id.desc);
mdesc.setText(desc);
}
public void setFile(final String data, String name, final Context ctx) {
TextView file_name= (TextView) mView.findViewById(R.id.file_name);
ImageView file_image= (ImageView) mView.findViewById(R.id.file_bt);
file_name.setText(name);
file_image.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Uri intentUri = Uri.parse(data);
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
intent.setData(intentUri);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
ctx.startActivity(intent);
}
});
}
public void setImage(final Context ctx, final String data) {
final ImageView imageView=(ImageView) mView.findViewById(R.id.post_img);
Picasso.with(ctx)
.load(data)
.networkPolicy(NetworkPolicy.OFFLINE)
.into(imageView,new Callback() {
@Override
public void onSuccess() {
}
@Override
public void onError() {
//Try again online if cache failed
Picasso.with(ctx).load(data).into((imageView));
}
});
}
}
这是我的模特课
public class PostData {
private String name;
private String data;
private String uid;
private String desc;
private String type;
private long timestamp;
public PostData() {
}
public PostData(String name, String data, String uid, String desc, String type, long timestamp) {
this.name = name;
this.data = data;
this.uid = uid;
this.desc = desc;
this.type = type;
this.timestamp = timestamp;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getData() {
return data;
}
public void setData(String data) {
this.data = data;
}
public String getUid() {
return uid;
}
public void setUid(String uid) {
this.uid = uid;
}
public String getDesc() {
return desc;
}
public void setDesc(String desc) {
this.desc = desc;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public long getTimestamp() {
return timestamp;
}
public void setTimestamp(long timestamp) {
this.timestamp = timestamp;
}
}
我的数据库结构有类型字段，它可以是图像，文件或文本，根据它，有三种布局。 这是应用程序的截图..
如果我找不到解决方案，我的项目将无法完成。请帮助!!这是我的日志..
10-09 09:45:56.720 8702-441/com.yashnagda.kkb D/FA: Logging event (FE): screen_view(_vs), Bundle[{firebase_event_origin(_o)=auto, firebase_previous_class(_pc)=MainActivity, firebase_previous_id(_pi)=7800829491751886780, firebase_screen_class(_sc)=BoardDetail, firebase_screen_id(_si)=7800829491751886794}]
10-09 09:45:56.728 8702-8702/com.yashnagda.kkb D/ActivityThreadInjector: clearCachedDrawables.
10-09 09:45:56.797 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:56.809 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:56.823 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:56.835 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:56.846 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:56.858 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:56.904 8702-9067/com.yashnagda.kkb D/OpenGLRenderer: endAllStagingAnimators on 0x55922c46e0 (RippleDrawable) with handle 0x5592cd6e50
10-09 09:45:56.905 8702-9067/com.yashnagda.kkb D/OpenGLRenderer: endAllStagingAnimators on 0x5592789e00 (LinearLayout) with handle 0x5592f7a610
10-09 09:45:58.808 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:58.897 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:59.132 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:45:59.382 8702-8702/com.yashnagda.kkb W/ClassMapper: No setter/field for key found on class com.yashnagda.kkb.PostData
10-09 09:46:01.780 8702-441/com.yashnagda.kkb V/FA: Inactivity, disconnecting from the service
答案 0 :(得分：0)
我认为您的值为空，请尝试此操作以确认您的数据Log.i("DataSnapTest",""+dataSnapshot.toString());
这将帮助您查看所有即将到来的数据，检查所有值是否正确。
希望这会对你有所帮助。