如何从 fire-base 检索数据到新活动中单击 RecyclerView
Posted
技术标签:
【中文标题】如何从 fire-base 检索数据到新活动中单击 RecyclerView【英文标题】：How to retrieve data from fire-base into a new activity On-click RecyclerView 【发布时间】：2020-06-02 00:23:11 【问题描述】：这是一个从 firebase 检索图书数据的应用，我想知道如何将特定数据检索到新活动中。就像，在单击 RecyclerView 时检索特定的图书数据。我能够在 RecyclerView 上获得 onclick 位置，但我不知道如何将它与 firebase 一起使用
这是我的代码：
public class SearchPage extends AppCompatActivity
EditText searchbar;
RecyclerView recyclerView;
DatabaseReference reference;
ArrayList <String> BookNameList;
ArrayList <String> AuthorNameList;
ArrayList <String> PicList;
ArrayList <String> PublisherList;
ArrayList <String> Shelfnols;
ArrayList <String> Desc;
SearchAdapter searchAdapter;
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search_page);
searchbar = (EditText) findViewById(R.id.searchbar);
reference = FirebaseDatabase.getInstance().getReference();
reference.keepSynced(true);
recyclerView = (RecyclerView) findViewById(R.id.rv);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.addItemDecoration(new DividerItemDecoration(this, LinearLayoutManager.VERTICAL));
BookNameList = new ArrayList <> ();
PublisherList = new ArrayList <> ();
AuthorNameList = new ArrayList <> ();
Shelfnols = new ArrayList <> ();
PicList = new ArrayList <> ();
Desc = new ArrayList <> ();
final ArrayList <String> uidlist = new ArrayList <String> ();
searchbar.addTextChangedListener(new TextWatcher()
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after)
@Override
public void onTextChanged(CharSequence s, int start, int before, int count)
@Override
public void afterTextChanged(Editable s)
if (!s.toString().isEmpty())
setAdapter(s.toString());
else
BookNameList.clear();
AuthorNameList.clear();
PicList.clear();
PublisherList.clear();
Shelfnols.clear();
Desc.clear();
uidlist.clear();
private void setAdapter(final String searchedString)
reference.child("books").addListenerForSingleValueEvent(new ValueEventListener()
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot)
BookNameList.clear();
AuthorNameList.clear();
PicList.clear();
PublisherList.clear();
Shelfnols.clear();
Desc.clear();
uidlist.clear();
int counter = 0;
for (DataSnapshot snapshot: dataSnapshot.getChildren())
String uid = snapshot.getKey();
String desc = snapshot.child("Desc").getValue(String.class);
String bookname = snapshot.child("bookname").getValue(String.class);
String author = snapshot.child("author").getValue(String.class);
String image = snapshot.child("image").getValue(String.class);
String publisher = snapshot.child("Publisher").getValue(String.class);
String shelfno = snapshot.child("Shelf_no").getValue(String.class);
try
if (bookname.toLowerCase().contains(searchedString.toLowerCase()))
BookNameList.add(bookname);
AuthorNameList.add(author);
PublisherList.add(publisher);
Shelfnols.add(shelfno);
PicList.add(image);
Desc.add(desc);
counter++;
else if (author.toLowerCase().contains(searchedString.toLowerCase()))
BookNameList.add(bookname);
AuthorNameList.add(author);
PublisherList.add(publisher);
Shelfnols.add(shelfno);
PicList.add(image);
Desc.add(desc);
counter++;
catch (Exception e)
Toast.makeText(getApplicationContext(), "not found", Toast.LENGTH_LONG).show();
if (counter == 15)
break;
SearchAdapter searchAdapter = new SearchAdapter(SearchPage.this, BookNameList, AuthorNameList, PicList, PublisherList, Shelfnols);
recyclerView.setAdapter(searchAdapter);
@Override
public void onCancelled(@NonNull DatabaseError databaseError)
);
);
这是我的适配器类
public class SearchAdapter extends RecyclerView.Adapter<SearchAdapter.SearchViewHolder>
public static final String id="key";
Context context;
ArrayList<String> BookNameList;
ArrayList<String> AuthorNameList;
ArrayList<String> PicList;
ArrayList<String> PublisherList;
ArrayList<String> Shelfnols;
LinearLayout booklayout;
class SearchViewHolder extends RecyclerView.ViewHolder
ImageView bookimage;
TextView bookname, authorname,publisher,shelfno;
public SearchViewHolder(@NonNull View itemView)
super(itemView);
bookimage = itemView.findViewById(R.id.Bookimg);
bookname = itemView.findViewById(R.id.BookName);
authorname = itemView.findViewById(R.id.AuthorName);
publisher = itemView.findViewById(R.id.Publications);
shelfno = itemView.findViewById(R.id.Shelfno);
booklayout=itemView.findViewById(R.id.LinLayout);
public SearchAdapter(Context context, ArrayList<String> bookNameList, ArrayList<String> authorNameList, ArrayList<String> picList,ArrayList<String> publisherList,ArrayList<String> shelfnols)
this.context = context;
BookNameList = bookNameList;
AuthorNameList = authorNameList;
PicList = picList;
PublisherList=publisherList;
Shelfnols=shelfnols;
@NonNull
@Override
public SearchAdapter.SearchViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType)
View view = LayoutInflater.from(context).inflate(R.layout.activity_search_layout,parent,false);
return new SearchAdapter.SearchViewHolder(view);
@Override
public void onBindViewHolder(@NonNull SearchViewHolder holder, final int position)
holder.bookname.setText(BookNameList.get(position));
holder.authorname.setText(AuthorNameList.get(position));
holder.publisher.setText(PublisherList.get(position));
holder.shelfno.setText(Shelfnols.get(position));
holder.itemView.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)
String t=String.valueOf(position);
Toast.makeText(v.getContext(), "Item is clicked" + t, Toast.LENGTH_SHORT).show();
);
booklayout.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)
);
这是我希望显示图书详细信息的新活动
public class Bookdetailslayout extends SearchPage
DatabaseReference reference;
TextView bookname,author,publisher,desc,location;
ImageView image;
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bookdetailslayout);
bookname = (TextView)findViewById(R.id.bkname);
author = (TextView) findViewById(R.id.aname);
publisher = (TextView) findViewById(R.id.pname);
desc = (TextView) findViewById(R.id.bkdescription);
location = (TextView) findViewById(R.id.bklocation);
String s = getIntent().getStringExtra("key");
DatabaseReference databaseReference=FirebaseDatabase.getInstance().getReference().child("books");
databaseReference.addValueEventListener(new ValueEventListener()
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot)
Bookdeets bookdeets=dataSnapshot.getValue(Bookdeets.class);
bookname.setText(bookdeets.getBookname());
@Override
public void onCancelled(@NonNull DatabaseError databaseError)
);
Glide.with(context).asBitmap().load(PicList.get(position)).placeholder(R.mipmap.ic_launcher_round).into(holder.bookimage);
@Override
public int getItemCount()
return BookNameList.size();
【问题讨论】：
看起来您在 Firebase 上获取数据，然后通过ArrayList<Object> 传递到适配器。您可以使用position 获取您的数据onClick：BookNameList.get(position).. 等
您需要将uid 传递给您的适配器，该适配器可用于从 Firebase 检索单个值
共享代码有什么问题？
请发布数据库结构以及您要发送意图的活动
@AlexMamo 此代码工作正常，但我一直在尝试将 onclick 侦听器设置为回收站视图，以转到将显示特定书籍详细信息的新活动
【参考方案1】：
holder.itemView.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)
Intent i = new Intent(context,BookdetailsActivity.class);
i.putExtra("bookname",bookname);
context.startActivity(i);
);
上面的代码启动新活动以显示有关新活动的详细信息，同时传递唯一键以从 firebase 检索数据。
在 BookDetailsActivity 内 使用
获取键值字符串名称 = getIntent().getStringExtra("bookname");
然后做你的事情以从 firebase 获取数据。
【讨论】：
我无法使用 bookname 它抛出一个错误，无法解决..我在我的适配器类的 onBindviewholder 下定义了它以上是关于如何从 fire-base 检索数据到新活动中单击 RecyclerView的主要内容，如果未能解决你的问题，请参考以下文章
单击 Listview 中的项目时，如何在新活动中从 Firebase 检索数据？
如何从 fire-base 为不同的产品风格 Android 生成不同的 json 文件