Question

请查看我的代码和所需的快照，我创建了一个新活动，可以在其中更新我的产品详细信息（注意：我将在稍后的活动中添加图片上传功能）。但是从我的代码中，我得到的结果就像附上快照的快照一样，该快照用红色标记了我想要的内容。我以管理员身份添加产品，并尝试以管理员身份进行更新，但是从另一个活动中我想更新我的数据。请帮助我

这是我正在尝试的活动代码

package com.commerce.daily.dailycommerce;

import android.app.ProgressDialog;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.TextView;
import com.commerce.daily.dailycommerce.ViewHolder.ProductViewHolder;
import com.commerce.daily.dailycommerce.model.Products;
import com.commerce.daily.dailycommerce.prevalent.prevalent;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import java.util.HashMap;

public class AdminUpdatingProductsActivity extends AppCompatActivity {

    private String UpdateDescription, updatePrice, updatePName;
    private TextView updateTxtBtn, changeImageTxt, closeTxtBtn;
    private EditText productUpdateName, productUpdateDescription, productUpdatePrice;

    private DatabaseReference updateProductRef;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_admin_updating_products);

        updateProductRef = FirebaseDatabase.getInstance().getReference().child("Products");

        updateTxtBtn = (TextView) findViewById(R.id.update_product_details_btn2);
        changeImageTxt = (TextView) findViewById(R.id.product_image_update_txt);
        closeTxtBtn = (TextView) findViewById(R.id.close_update_product_btn);
        productUpdateName = (EditText) findViewById(R.id.update_product_name);
        productUpdateDescription = (EditText) findViewById(R.id.update_product_description);
        productUpdatePrice = (EditText) findViewById(R.id.update_product_price);


        updateTxtBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v)
            {
                updateinformation();
            }
        });

    }

    private void updateinformation() {

        updatePName = productUpdateName.getText().toString();
        UpdateDescription = productUpdateDescription.getText().toString();
        updatePrice = productUpdatePrice.getText().toString();

        HashMap<String, Object> ProductMap = new HashMap<>();
        ProductMap.put("pname", updatePName);
        ProductMap.put("price", updatePrice);
        ProductMap.put("description", UpdateDescription);

        updateProductRef.updateChildren(ProductMap);

    }
   }

这是xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.commerce.daily.dailycommerce.AdminUpdatingProductsActivity">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar_update_product"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/colorPrimary">

        <android.support.v7.widget.Toolbar
            android:id="@+id/tollbar_update_product"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent">

                <TextView
                    android:id="@+id/close_update_product_btn"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Close"
                    android:textColor="@android:color/white"
                    android:textSize="17sp"
                    android:textStyle="bold"
                    android:layout_alignParentStart="true"
                    android:layout_alignParentLeft="true"/>

                <TextView
                    android:id="@+id/update_product_details_btn2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Update"
                    android:textColor="@android:color/white"
                    android:textSize="17sp"
                    android:textStyle="bold"
                    android:layout_marginRight="10dp"
                    android:layout_alignParentEnd="true"
                    android:layout_alignParentRight="true"/>

            </RelativeLayout>

        </android.support.v7.widget.Toolbar>

    </android.support.design.widget.AppBarLayout>

    <ImageView
        android:id="@+id/product_image_update"
        android:layout_below="@+id/app_bar_update_product"
        android:layout_width="250dp"
        android:layout_height="150dp"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp"
        android:src="@drawable/ic_menu_camera"/>

    <TextView
        android:id="@+id/product_image_update_txt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/product_image_update"
        android:text="Change Image"
        android:layout_marginTop="4dp"
        android:textColor="@android:color/black"
        android:textSize="17sp"
        android:textStyle="bold"
        android:layout_marginRight="10dp"
        android:layout_centerHorizontal="true"/>

    <EditText
        android:id="@+id/update_product_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/product_image_update_txt"
        android:inputType="textMultiLine"
        android:layout_marginTop="30dp"
        android:padding="20dp"
        android:hint="Product Name..."
        android:layout_marginLeft="45dp"
        android:layout_marginRight="45dp"
        android:background="@drawable/input_design"/>

    <EditText
        android:id="@+id/update_product_description"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/update_product_name"
        android:inputType="textMultiLine"
        android:layout_marginTop="6dp"
        android:padding="20dp"
        android:hint="Product Description..."
        android:layout_marginLeft="45dp"
        android:layout_marginRight="45dp"
        android:background="@drawable/input_design"/>

    <EditText
        android:id="@+id/update_product_price"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/update_product_description"
        android:inputType="textMultiLine"
        android:layout_marginTop="6dp"
        android:padding="20dp"
        android:hint="Product Price..."
        android:layout_marginLeft="45dp"
        android:layout_marginRight="45dp"
        android:background="@drawable/input_design"/>

</RelativeLayout>

package com.commerce.daily.dailycommerce;

import android.content.DialogInterface;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Toast;

import com.commerce.daily.dailycommerce.Interface.ItemClickListner;
import com.commerce.daily.dailycommerce.ViewHolder.ProductViewHolder;
import com.commerce.daily.dailycommerce.model.Products;
import com.commerce.daily.dailycommerce.prevalent.prevalent;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.squareup.picasso.Picasso;

import java.util.HashMap;

public class AdminListedProductActivity extends AppCompatActivity
{
    private DatabaseReference AdminProductsRef;
    private RecyclerView recyclerView;
    RecyclerView.LayoutManager layoutManager;




    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_admin_listed_product);




        AdminProductsRef = FirebaseDatabase.getInstance().getReference().child("Products");

        recyclerView = findViewById(R.id.productlist_recycler);
        recyclerView.setHasFixedSize(true);
        layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
    }

    @Override
    protected void onStart() {
        super.onStart();

        FirebaseRecyclerOptions<Products> options =
                new FirebaseRecyclerOptions.Builder<Products>()
                        .setQuery(AdminProductsRef, Products.class)
                        .build();




        final FirebaseRecyclerAdapter<Products, ProductViewHolder> adapter =
                new FirebaseRecyclerAdapter<Products, ProductViewHolder>(options)
                {
                    @Override
                    protected void onBindViewHolder(@NonNull ProductViewHolder holder, final int position, @NonNull final Products model)
                    {

                        holder.txtProductName.setText(model.getPname());
                        holder.txtProductDescription.setText(model.getDescription());
                        holder.txtProductPrice.setText("Price = "+ model.getPrice());
                        Picasso.get().load(model.getImage()).into(holder.imageView);


                        holder.itemView.setOnClickListener(new View.OnClickListener() {
                            @Override
                            public void onClick(View v)
                            {
                                CharSequence options[] = new CharSequence[]
                                        {
                                                "Edit",
                                                "Remove"
                                        };

                                AlertDialog.Builder builder = new AlertDialog.Builder(AdminListedProductActivity.this);
                                builder.setTitle("Edit/Delete");
                                builder.setItems(options, new DialogInterface.OnClickListener() {
                                    @Override
                                    public void onClick(DialogInterface dialog, int which)
                                    {


                                        if(which == 0)
                                        {
                                            
                                          updateProducts();

                                        }

                                        if(which == 1)
                                        {
                                            FirebaseDatabase.getInstance().getReference().child("Products")
                                                    .child(model.getDate() + model.getTime())
                                                    .removeValue()
                                                    .addOnCompleteListener(new OnCompleteListener<Void>() {
                                                        @Override
                                                        public void onComplete(@NonNull Task<Void> task)
                                                        {
                                                            if(task.isSuccessful())
                                                            {
                                                                Toast.makeText(AdminListedProductActivity.this, "Item Removed Successfully.", Toast.LENGTH_SHORT).show();

                                                                Intent intent = new Intent(AdminListedProductActivity.this, AdminCategoryActivity.class);
                                                                startActivity(intent);

                                                            }
                                                        }
                                                    });
                                        }
                                    }
                                });

                                builder.show();

                            }
                        });

                    }

                    @NonNull
                    @Override
                    public ProductViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.product_items_layout, parent, false);
                        ProductViewHolder holder = new ProductViewHolder(view);
                        return  holder;

                    }
                };

        recyclerView.setAdapter(adapter);
        adapter.startListening();


    }

    private void updateProducts()
    {

        finish();



    }

    @Override
    public void onBackPressed()
    {
         super.onBackPressed();
    }

}

这是我的产品类，位于名为model的程序包下

package com.commerce.daily.dailycommerce.model;

/**
 * Created by Romen on 2/10/2019.
 */

public class Products
{
    private String pname, description, price,image, category, pid, date, time;

    public Products()
    {

    }

    public Products(String pname, String description, String price, String image, String category, String pid, String date, String time)
    {
        this.pname = pname;
        this.description = description;
        this.price = price;
        this.image = image;
        this.category = category;
        this.pid = pid;
        this.date = date;
        this.time = time;
    }

    public String getPname() {
        return pname;
    }

    public void setPname(String pname) {
        this.pname = pname;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }

    public String getCategory() {
        return category;
    }

    public void setCategory(String category) {
        this.category = category;
    }

    public String getPid() {
        return pid;
    }

    public void setPid(String pid) {
        this.pid = pid;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }
}

Answer 1

您无法以这种方式更新所需的特定节点，因为未指定要更新其数据的节点。在updateProductRef.updateChildren(ProductMap);行中，您指定“产品”节点，然后在其中添加数据，而不是应指定要更新它的节点。

要实现此目的，您应该为每个节点放置一个唯一的ID（例如数据库中的“ pid”属性），然后将其与当前活动中的“ pid”进行比较。

在您的类“产品”中为“ pid”属性添加getter和setter方法。
从列表中单击包含所有“产品”的特殊产品时，将获得该商品的位置并从中获取“ pid”，如下所示：
获取当前的“ pid”项目后，通过对新活动使用intent对象上的putExtra()方法，将其有意图地发送。
捕获先前活动发送的字符串，并将其与数据库中的所有pid属性进行比较，然后获取该产品的密钥并将其设置为子级。

修改

实际上，我无法正确理解您的代码，或者这是一个错误，因此，我构建了另一个完全不同的代码。

为显示产品创建适配器类：

public class AdapterProducts extends RecyclerView.Adapter<AdapterProducts.HolderProuducts> { Context context; List<products> listProuducts;

private AdapterProducts.OnItemClickListener mListener;

//This interface for handle clicked on an item in recyclerview
public interface OnItemClickListener {
    void onItemClick(int position);
}

public void setOnItemClickListener(AdapterProducts.OnItemClickListener listener) {
    mListener = listener;
}

//constrouctor
public AdapterProducts(Context context,List<products> listProuducts)
{
    this.listProuducts = listProuducts;
    this.context = context;

}

@Override
public AdapterProducts.HolderProuducts onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    View row = LayoutInflater.from(viewGroup.getContext())
            .inflate(R.layout.row_item_products, viewGroup, false);
    AdapterProducts.HolderProuducts holder = new AdapterProducts.HolderProuducts(row, mListener);
    return holder;
}

@Override
public void onBindViewHolder(@NonNull AdapterProducts.HolderProuducts holderProuducts, int i) {

    holderProuducts.txtProductName.setText(model.getPname());
    holderProuducts.txtProductDescription.setText(model.getDescription());
    holderProuducts.txtProductPrice.setText("Price = "+ model.getPrice());
    Picasso.get().load(model.getImage()).into(holderProuducts.imageView);
}

@Override
public int getItemCount() {
    return listProuducts.size();
}

public class HolderProuducts extends RecyclerView.ViewHolder{
    TextView txtProductName,txtProductDescription,txtProductPrice;
    ImageView imageView;

    public HolderProuducts(@NonNull View itemView, final AdapterProducts.OnItemClickListener listener) {
        super(itemView);

        txtProductName = (TextView) itemView.findViewById(R.id.name_product);
        txtProductDescription = (TextView) itemView.findViewById(R.id.description_product);
        txtProductPrice = (TextView) itemView.findViewById(R.id.price_product);

        imageView = (ImageView) itemView.findViewById(R.id.image_view);

        itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (listener != null) {
                    int position = getAdapterPosition();
                    if (position != RecyclerView.NO_POSITION) {
                        listener.onItemClick(position);
                    }
                }
            }

        });
    }
}

}

在您的AdminListedProductActivity中：

`

公共类AdminListedProductActivity扩展了AppCompatActivity {

RecyclerView mRecyclerProducts;
List<Products> listProducts;
LinearLayoutManager layoutManager;
AdapterProducts mAdapterProducts;

DatabaseReference AdminProductsRef;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_admin_listed_product);

    AdminProductsRef = FirebaseDatabase.getInstance().getReference().child("Products");


    listProducts = new ArrayList();
    mRecyclerProducts = findViewById(R.id.productlist_recycler);
    mRecyclerProducts.setHasFixedSize(true);
    layoutManager = new LinearLayoutManager(this);
    mRecyclerProducts.setLayoutManager(layoutManager);

    listProducts = displayProuductsInList();

    mAdapterProducts.setOnItemClickListener(new AdapterProducts.OnItemClickListener() {
        @Override
        public void onItemClick(int position) {
            Products productsClicked = listProducts.get(position);

            //This pid for the item that clicked on it
            String pid = productsClicked.getPid();

            Intent intent = new Intent(AdminListedProductActivity .this,AdminUpdatingProductsActivity.class);

            //send it with intent to activity update
            intent.putExtra("pid",pid);
            startActivity(intent);
        }
    });
}

//This method for get all products from database
private List<Products> displayProuductsInList() {
    List<Products> list = new ArrayList();

    AdminProductsRef.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            for (DataSnapshot data : dataSnapshot.getChildren()) {
                Products products = data.getValue(Products.class);
                list.add(products);
            }
            mRecyclerProducts.setLayoutManager(new LinearLayoutManager(AdminListedProductActivity .this));
            mAdapterProducts.notifyDataSetChanged();
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });

}

} `

在您的AdminUpdatingProductsActivity中：

public class AdminUpdatingProductsActivity extends AppCompatActivity {

private String UpdateDescription, updatePrice, updatePName;
private TextView updateTxtBtn, changeImageTxt, closeTxtBtn;
private EditText productUpdateName, productUpdateDescription, productUpdatePrice;

DatabaseReference updateProductRef;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_admin_listed_product);

    updateProductRef = FirebaseDatabase.getInstance().getReference().child("Products");

    updateTxtBtn = (TextView) findViewById(R.id.update_product_details_btn2);
    changeImageTxt = (TextView) findViewById(R.id.product_image_update_txt);
    closeTxtBtn = (TextView) findViewById(R.id.close_update_product_btn);
    productUpdateName = (EditText) findViewById(R.id.update_product_name);
    productUpdateDescription = (EditText) findViewById(R.id.update_product_description);
    productUpdatePrice = (EditText) findViewById(R.id.update_product_price);


    updateTxtBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v)
        {
            updateinformation();
        }
    });
}


private void updateinformation() {

    Intent intent = getIntent();
    String pidFromPriveosActivity = intent.getStringExtra("pid");

    updatePName = productUpdateName.getText().toString();
    UpdateDescription = productUpdateDescription.getText().toString();
    updatePrice = productUpdatePrice.getText().toString();

    HashMap<String, Object> ProductMap = new HashMap<>();
    ProductMap.put("pname", updatePName);
    ProductMap.put("price", updatePrice);
    ProductMap.put("description", UpdateDescription);

    updateProductRef.addListenerForSingleValueEvent(new ValueEventListener() {
        String currentKey;

        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            for (DataSnapshot data : dataSnapshot.getChildren())
            {
                //get each "pid" in database for all products
                String pidsInDataBase = data.child("pid").getValue(String.class);

                //compare "pid" from previous activity with each "pid" in database
                if (pidFromPriveosActivity.equals(pidsInDataBase)){

                    //get key for product that clicke on it in recyclerview
                    currentKey = data.getKey();
                }
            }

            //update data for this item
            updateProductRef.child(currentKey).updateChildren(ProductMap);
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });

}}

当子代是由当前日期和当前时间生成的随机密钥时，如何从新活动更新Firebase数据节点

1 个答案: