Java 如何将recyclerview连接到firebase数据库插入、更新和删除数据
我创建了一个包含Java 如何将recyclerview连接到firebase数据库插入、更新和删除数据,java,android,firebase,firebase-realtime-database,android-recyclerview,Java,Android,Firebase,Firebase Realtime Database,Android Recyclerview,我创建了一个包含recyclerview的应用程序，我从alertDilog在recyclerview数组列表中添加数据，并根据用户的点击编辑、删除alertDilog中的数据。它工作正常，但当我将我的应用程序连接到firebase数据库时，我的应用程序工作不正常 Recyclerview适配器： public class recyclerviewadapter extends RecyclerView.Adapter<recyclerviewadapter.Viewholder>
recyclerviewalertDilogrecyclerview数组列表中添加数据，并根据用户的点击编辑、删除alertDilog
中的数据。它工作正常，但当我将我的应用程序连接到firebase数据库时，我的应用程序工作不正常
Recyclerview适配器：
public class recyclerviewadapter extends RecyclerView.Adapter<recyclerviewadapter.Viewholder> {
ArrayList<customitem> datalist;
vonclick mclick;
@NonNull
@Override
public Viewholder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerviewexdesign,parent,false);
return new Viewholder(v,mclick);
}
public recyclerviewadapter(ArrayList<customitem> datalist) {
this.datalist = datalist;
}
@Override
public void onBindViewHolder(@NonNull Viewholder holder, int position) {
customitem n = datalist.get(position);
holder.productname.setText(n.getproductname());
}
@Override
public int getItemCount() {
return datalist.size();
}
public class Viewholder extends RecyclerView.ViewHolder {
TextView productname;
public Viewholder(@NonNull View itemView, final vonclick listener) {
super(itemView);
productname = itemView.findViewById(R.id.titleid);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (listener!=null){
int possition =getAdapterPosition();
if (possition !=RecyclerView.NO_POSITION){
listener.cclick(possition);
}
}
}
});
}
}
public interface vonclick{
void cclick(int possition);
}
public void recyclerviewonclicl(vonclick possition){
mclick=possition;
}
}
public class customitem {
String productname,size,price,box;
int kg;
public customitem(){
}
public customitem(String productname, String size,String price,String box,int kg) {
this.productname = productname;
this.size = size;
this.price = price;
this.box = box;
this.kg = kg;
}
public String getproductname() {
return productname;
}
public void setproductname(String productname) {
this.productname = productname;
}
public String getsize() {
return size;
}
public void setsize(String size) {
this.size = size;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
public String getBox() {
return box;
}
public void setBox(String box) {
this.box = box;
}
public int getKg() {
return kg;
}
public void setKg(int kg) {
this.kg = kg;
}
}
public class addproduct extends AppCompatActivity {
RecyclerView recyclerView;
ArrayList<customitem> datalist =new ArrayList<customitem>();
FirebaseDatabase mdatabase;
DatabaseReference mreference;
EditText productname,price,size,b2;
Spinner sizespinner;
Button okbutton;
View mview;
ImageView cancel;
AlertDialog d;
AlertDialog.Builder alert;
recyclerviewadapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_addproduct);
getSupportActionBar().setTitle("Add product");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mdatabase = FirebaseDatabase.getInstance();
//?????????????????????? my firebase referance ????????????
mreference = mdatabase.getReference().child("product");
mreference.keepSynced(true);
recyclerView = findViewById(R.id.recyclerviewid);
buildrecyclerview();
//mreference.child("product").setValue(datalist);
}
public void buildrecyclerview(){
adapter = new recyclerviewadapter(datalist);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new GridLayoutManager(this,4));
recyclerView.setAdapter(adapter);
mreference.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot dataSnapshot1:dataSnapshot.getChildren()){
customitem j =dataSnapshot1.getValue(customitem.class);
datalist.add(j);
}
adapter.notifyDataSetChanged();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
adapter.recyclerviewonclicl(new recyclerviewadapter.vonclick() {
@Override
public void cclick(final int possition) {
//?????????????? alert dilog two for delete and update data ????????????????
AlertDialog.Builder bl = new AlertDialog.Builder(addproduct.this);
View v = getLayoutInflater().inflate(R.layout.manageralertdilogtwo,null);
bl.setView(v);
d=bl.create();
d.show();
final EditText productname2 = v.findViewById(R.id.productname2);
final EditText size2 = v.findViewById(R.id.packsizeid2);
final EditText price2 = v.findViewById(R.id.priceid2);
final EditText box2 = v.findViewById(R.id.Box2);
Button okbtn = v.findViewById(R.id.okbuttonid2);
Button dltbtn = v.findViewById(R.id.deleteid);
ImageView cross =v.findViewById(R.id.cancelid2);
final Spinner sp =v.findViewById(R.id.spinnerid2);
//String pn = datalist.get(possition).getproductname();
productname2.setText(datalist.get(possition).getproductname());
size2.setText(datalist.get(possition).getsize());
price2.setText(datalist.get(possition).getPrice());
box2.setText(datalist.get(possition).getBox());
sp.setSelection(datalist.get(possition).getKg());
cross.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
}
});
okbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//?????????????? update data accroding user selectiong ??????????????
//datalist.get(possition).setproductname(productname2.getText().toString());
//datalist.get(possition).setPrice(price2.getText().toString());
//datalist.get(possition).setsize(size2.getText().toString());
//datalist.get(possition).setBox(box2.getText().toString());
//datalist.get(possition).setKg(sp.getSelectedItemPosition());
customitem m = new customitem(productname2.getText().toString(),size2.getText().toString()
,price2.getText().toString(),box2.getText().toString(),sp.getSelectedItemPosition());
mreference.child(String.valueOf(datalist.get(possition))).setValue(m);
d.dismiss();
}
});
dltbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//???????????????? delete data from recycler view accroding user selection ???????????
//datalist.remove(possition);
mreference.child(String.valueOf(datalist.get(possition))).removeValue();
// adapter.notifyDataSetChanged();
d.dismiss();
}
});
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.addproductmenu,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case R.id.addproduct:
buildalert();
break;
case R.id.seedetails:
Intent n = new Intent(addproduct.this,managermain.class);
startActivity(n);
break;
}
return super.onOptionsItemSelected(item);
}
public void buildalert(){
//?????? alert dilog one for take data ???????????????
alert = new AlertDialog.Builder(addproduct.this);
mview = getLayoutInflater().inflate(R.layout.manageralertalertdilog,null);
productname = mview.findViewById(R.id.productname);
price = mview.findViewById(R.id.priceid);
alert.setCancelable(true);
size = mview.findViewById(R.id.packsizeid);
cancel = mview.findViewById(R.id.cancelid);
sizespinner = mview.findViewById(R.id.spinnerid);
okbutton = mview.findViewById(R.id.okbuttonid);
b2 = mview.findViewById(R.id.Box);
alert.setView(mview);
final AlertDialog dl = alert.create();
dl.show();
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dl.dismiss();
}
});
okbutton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (productnamem() && sizem()){
//add data from alert dilog
String productnm = productname.getText().toString();
String pricec = price.getText().toString();
String sizee = size.getText().toString();
int kg = sizespinner.getSelectedItemPosition();
String box= b2.getText().toString();
//?? add data in recyclerview from alert dilog ???????????????
//datalist.add(new customitem(productnm,sizee,pricec,box,kg));
customitem n = new customitem(productnm,sizee,pricec,box,kg);
mreference.child(String.valueOf(datalist.size())).setValue(n);
//adapter.notifyDataSetChanged();
//mreference.setValue(datalist);
dl.dismiss();
}
}
});
}
public boolean productnamem(){
if (productname.getText().toString().trim().isEmpty()){
productname.setError("Please fill it");
productname.setFocusable(true);
return false;
}
else {
return true;
}
}
public boolean sizem(){
if (size.getText().toString().trim().isEmpty()){
size.setError("Please fill it");
size.setFocusable(true);
return false;
}
else {
return true;
}
}
}
最后一个主类：
public class recyclerviewadapter extends RecyclerView.Adapter<recyclerviewadapter.Viewholder> {
ArrayList<customitem> datalist;
vonclick mclick;
@NonNull
@Override
public Viewholder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerviewexdesign,parent,false);
return new Viewholder(v,mclick);
}
public recyclerviewadapter(ArrayList<customitem> datalist) {
this.datalist = datalist;
}
@Override
public void onBindViewHolder(@NonNull Viewholder holder, int position) {
customitem n = datalist.get(position);
holder.productname.setText(n.getproductname());
}
@Override
public int getItemCount() {
return datalist.size();
}
public class Viewholder extends RecyclerView.ViewHolder {
TextView productname;
public Viewholder(@NonNull View itemView, final vonclick listener) {
super(itemView);
productname = itemView.findViewById(R.id.titleid);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (listener!=null){
int possition =getAdapterPosition();
if (possition !=RecyclerView.NO_POSITION){
listener.cclick(possition);
}
}
}
});
}
}
public interface vonclick{
void cclick(int possition);
}
public void recyclerviewonclicl(vonclick possition){
mclick=possition;
}
}
public class customitem {
String productname,size,price,box;
int kg;
public customitem(){
}
public customitem(String productname, String size,String price,String box,int kg) {
this.productname = productname;
this.size = size;
this.price = price;
this.box = box;
this.kg = kg;
}
public String getproductname() {
return productname;
}
public void setproductname(String productname) {
this.productname = productname;
}
public String getsize() {
return size;
}
public void setsize(String size) {
this.size = size;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
public String getBox() {
return box;
}
public void setBox(String box) {
this.box = box;
}
public int getKg() {
return kg;
}
public void setKg(int kg) {
this.kg = kg;
}
}
public class addproduct extends AppCompatActivity {
RecyclerView recyclerView;
ArrayList<customitem> datalist =new ArrayList<customitem>();
FirebaseDatabase mdatabase;
DatabaseReference mreference;
EditText productname,price,size,b2;
Spinner sizespinner;
Button okbutton;
View mview;
ImageView cancel;
AlertDialog d;
AlertDialog.Builder alert;
recyclerviewadapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_addproduct);
getSupportActionBar().setTitle("Add product");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mdatabase = FirebaseDatabase.getInstance();
//?????????????????????? my firebase referance ????????????
mreference = mdatabase.getReference().child("product");
mreference.keepSynced(true);
recyclerView = findViewById(R.id.recyclerviewid);
buildrecyclerview();
//mreference.child("product").setValue(datalist);
}
public void buildrecyclerview(){
adapter = new recyclerviewadapter(datalist);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new GridLayoutManager(this,4));
recyclerView.setAdapter(adapter);
mreference.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot dataSnapshot1:dataSnapshot.getChildren()){
customitem j =dataSnapshot1.getValue(customitem.class);
datalist.add(j);
}
adapter.notifyDataSetChanged();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
adapter.recyclerviewonclicl(new recyclerviewadapter.vonclick() {
@Override
public void cclick(final int possition) {
//?????????????? alert dilog two for delete and update data ????????????????
AlertDialog.Builder bl = new AlertDialog.Builder(addproduct.this);
View v = getLayoutInflater().inflate(R.layout.manageralertdilogtwo,null);
bl.setView(v);
d=bl.create();
d.show();
final EditText productname2 = v.findViewById(R.id.productname2);
final EditText size2 = v.findViewById(R.id.packsizeid2);
final EditText price2 = v.findViewById(R.id.priceid2);
final EditText box2 = v.findViewById(R.id.Box2);
Button okbtn = v.findViewById(R.id.okbuttonid2);
Button dltbtn = v.findViewById(R.id.deleteid);
ImageView cross =v.findViewById(R.id.cancelid2);
final Spinner sp =v.findViewById(R.id.spinnerid2);
//String pn = datalist.get(possition).getproductname();
productname2.setText(datalist.get(possition).getproductname());
size2.setText(datalist.get(possition).getsize());
price2.setText(datalist.get(possition).getPrice());
box2.setText(datalist.get(possition).getBox());
sp.setSelection(datalist.get(possition).getKg());
cross.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
}
});
okbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//?????????????? update data accroding user selectiong ??????????????
//datalist.get(possition).setproductname(productname2.getText().toString());
//datalist.get(possition).setPrice(price2.getText().toString());
//datalist.get(possition).setsize(size2.getText().toString());
//datalist.get(possition).setBox(box2.getText().toString());
//datalist.get(possition).setKg(sp.getSelectedItemPosition());
customitem m = new customitem(productname2.getText().toString(),size2.getText().toString()
,price2.getText().toString(),box2.getText().toString(),sp.getSelectedItemPosition());
mreference.child(String.valueOf(datalist.get(possition))).setValue(m);
d.dismiss();
}
});
dltbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//???????????????? delete data from recycler view accroding user selection ???????????
//datalist.remove(possition);
mreference.child(String.valueOf(datalist.get(possition))).removeValue();
// adapter.notifyDataSetChanged();
d.dismiss();
}
});
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.addproductmenu,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case R.id.addproduct:
buildalert();
break;
case R.id.seedetails:
Intent n = new Intent(addproduct.this,managermain.class);
startActivity(n);
break;
}
return super.onOptionsItemSelected(item);
}
public void buildalert(){
//?????? alert dilog one for take data ???????????????
alert = new AlertDialog.Builder(addproduct.this);
mview = getLayoutInflater().inflate(R.layout.manageralertalertdilog,null);
productname = mview.findViewById(R.id.productname);
price = mview.findViewById(R.id.priceid);
alert.setCancelable(true);
size = mview.findViewById(R.id.packsizeid);
cancel = mview.findViewById(R.id.cancelid);
sizespinner = mview.findViewById(R.id.spinnerid);
okbutton = mview.findViewById(R.id.okbuttonid);
b2 = mview.findViewById(R.id.Box);
alert.setView(mview);
final AlertDialog dl = alert.create();
dl.show();
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dl.dismiss();
}
});
okbutton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (productnamem() && sizem()){
//add data from alert dilog
String productnm = productname.getText().toString();
String pricec = price.getText().toString();
String sizee = size.getText().toString();
int kg = sizespinner.getSelectedItemPosition();
String box= b2.getText().toString();
//?? add data in recyclerview from alert dilog ???????????????
//datalist.add(new customitem(productnm,sizee,pricec,box,kg));
customitem n = new customitem(productnm,sizee,pricec,box,kg);
mreference.child(String.valueOf(datalist.size())).setValue(n);
//adapter.notifyDataSetChanged();
//mreference.setValue(datalist);
dl.dismiss();
}
}
});
}
public boolean productnamem(){
if (productname.getText().toString().trim().isEmpty()){
productname.setError("Please fill it");
productname.setFocusable(true);
return false;
}
else {
return true;
}
}
public boolean sizem(){
if (size.getText().toString().trim().isEmpty()){
size.setError("Please fill it");
size.setFocusable(true);
return false;
}
else {
return true;
}
}
}
公共类addproduct扩展了AppCompatActivity{
回收视图回收视图；
ArrayList datalist=新的ArrayList（）；
Firebase数据库mdatabase；
数据库参考文献；
EditText产品名称、价格、大小、b2；
纺纱机；
按钮OK按钮；
视图视图；
图像视图取消；
警惕的对话；
AlertDialog.Builder警报；
循环水适配器；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u addproduct）；
getSupportActionBar（）.setTitle（“添加产品”）；
getSupportActionBar（）.setDisplayHomeAsUpEnabled（true）；
mdatabase=FirebaseDatabase.getInstance（）；
//我的火基参考资料？？？？？？？？？？？？
mrreference=mdatabase.getReference（）.child（“产品”）；
mreference.keepSynced（true）；
recyclerView=findViewById（R.id.recyclerviewid）；
buildrecyclerview（）；
//mreference.child（“产品”）.setValue（数据列表）；
}
公共void buildrecyclerview（）{
适配器=新的RecycleServiceAdapter（数据列表）；
recyclerView.setHasFixedSize（true）；
setLayoutManager（新的GridLayoutManager（this，4））；
recyclerView.setAdapter（适配器）；
mreference.addValueEventListener（新的ValueEventListener（）{
@凌驾
public void onDataChange（@NonNull DataSnapshot DataSnapshot）{
对于（DataSnapshot dataSnapshot1:DataSnapshot.getChildren（））{
customitem j=dataSnapshot1.getValue（customitem.class）；
数据表.添加（j）；
}
adapter.notifyDataSetChanged（）；
}
@凌驾
已取消的公共void（@NonNull DatabaseError DatabaseError）{
}
});
adapter.RecycleServiceOnClicl（新的RecycleServiceAdapter.vonclick（）{
@凌驾
公共无效点击（最终整数占有）{
//提醒dilog 2删除和更新数据？？？？？？？？？？？？？？？？
AlertDialog.Builder bl=新建AlertDialog.Builder（addproduct.this）；
视图v=getLayoutInflater（）.inflate（R.layout.manageralertdilogtwo，null）；
bl.setView（v）；
d=bl.create（）；
d、 show（）；
final EditText productname2=v.findViewById（R.id.productname2）；
最终编辑文本大小2=v.findviewbyd（R.id.packsizeid2）；
最终编辑文本价格2=v.findviewbyd（R.id.priceid2）；
最终编辑文本框2=v.findviewbyd（R.id.box2）；
按钮okbtn=v.findViewById（R.id.OKButonid2）；
按钮dltbtn=v.findViewById（R.id.deleteid）；
ImageView cross=v.findViewById（R.id.cancelid2）；
最终喷丝器sp=v.findViewById（R.id.喷丝器ID2）；
//字符串pn=datalist.get（position）.getproductname（）；
productname2.setText（datalist.get（position.getproductname（））；
setText（datalist.get（position.getsize（））；
price2.setText（datalist.get（position.getPrice（））；
setText（datalist.get（position.getBox（））；
sp.setSelection（datalist.get（position.getKg（））；
cross.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
d、 解雇（）；
}
});
okbtn.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
//根据用户选择更新数据？？？？？？？？？？？？？？
//datalist.get（position.setproductname（productname2.getText（）.toString（））；
//datalist.get（position.setPrice（price2.getText（）.toString（））；
//datalist.get（position）.setsize（size2.getText（）.toString（））；
//datalist.get（position.setBox（box2.getText（）.toString（））；
//get（position）.setKg（sp.getSelectedItemPosition（））；
customitem m=新的customitem（productname2.getText（）.toString（），size2.getText（）.toString（））
，price2.getText（）.toString（），box2.getText（）.toString（），sp.getSelectedItemPosition（））；
mrreference.child（String.valueOf（datalist.get（position）））.setValue（m）；
d、 解雇（）；
}
});
dltbtn.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
//根据用户选择从回收器视图中删除数据？？？？？？？？？？？
//数据列表。删除（占有）；
mrreference.child（String.valueOf（datalist.get（position）））.removeValue（）；
//adapter.notifyDataSetChanged（）；
d、 解雇（）；
}
});
}
});
}
@凌驾
公共布尔onCreateOptions菜单（菜单）{
getMenuInflater（）.充气（R.menu.addproductmenu，menu）；
返回true；
}
@凌驾
公共布尔值onOptionsItemSelected（菜单项项）{
开关（item.getItemId（））{