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Java 运行特定活动时出现LogCat错误_Java_Android_Android Studio_Android Recyclerview - Fatal编程技术网

Java 运行特定活动时出现LogCat错误

Java 运行特定活动时出现LogCat错误,java,android,android-studio,android-recyclerview,Java,Android,Android Studio,Android Recyclerview,我的应用程序没有生成java文件中请求的信息。人们希望该应用程序能够生成一个信息回收器视图,该视图存储在phpMyAdmin数据库中 然而,我得到的只是一个空白/空的活动 < Log>正在产生一个与RealdReVIEW有关的错误,但是,我不知道如何绕过这个错误/知道这是否是导致空白活动的错误。 LogCat 02-07 11:28:55.936 5622-5622/com.example.xxxx.myapplication E/RecyclerView: No adapter attache

我的应用程序没有生成java文件中请求的信息。人们希望该应用程序能够生成一个信息回收器视图,该视图存储在phpMyAdmin数据库中

然而,我得到的只是一个空白/空的活动

< Log>正在产生一个与RealdReVIEW有关的错误,但是,我不知道如何绕过这个错误/知道这是否是导致空白活动的错误。 LogCat

02-07 11:28:55.936 5622-5622/com.example.xxxx.myapplication E/RecyclerView: No adapter attached; skipping layout
适配器

package com.example.benchalmers.myapplication;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ProductViewHolder> {


    private Context mCtx;
    private List<Product> productList;

    public ProductAdapter(Context mCtx, List<Product> productList) {
        this.mCtx = mCtx;
        this.productList = productList;
    }

    @Override
    public ProductViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        LayoutInflater inflater = LayoutInflater.from(mCtx);
        View view = inflater.inflate(R.layout.list_layout, null);
        return new ProductViewHolder(view);

    }

    @Override
    public void onBindViewHolder(ProductViewHolder holder, int position) {

        Product product = productList.get(position);

        holder.textViewType.setText(product.getType());
        holder.textViewProperty.setText(product.getProperty());
        holder.textViewMoreInfo.setText(String.valueOf(product.getMoreInfo()));
        holder.textViewDate.setText(String.valueOf(product.getDate()));

        //holder.imageView.setImageDrawable(mCtx.getResources().getDrawable(product.getImage()));
    }

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

    class ProductViewHolder extends RecyclerView.ViewHolder {

        ImageView imageView;
        TextView textViewType, textViewProperty, textViewMoreInfo, textViewDate;

        public ProductViewHolder(View itemView) {
            super(itemView);

            imageView = itemView.findViewById(R.id.imageView);
            textViewType = itemView.findViewById(R.id.textViewType);
            textViewProperty = itemView.findViewById(R.id.textViewProperty);
            textViewMoreInfo = itemView.findViewById(R.id.textViewMoreInfo);
            textViewDate = itemView.findViewById(R.id.textViewDate);

        }
    }
}
package com.example.benchalmers.myapplication;
导入android.content.Context;
导入android.support.v7.widget.RecyclerView;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.ImageView;
导入android.widget.TextView;
导入java.util.List;
公共类ProductAdapter扩展了RecyclerView.Adapter{
私有上下文mCtx;
私有列表产品列表;
公共产品适配器(上下文mCtx,列表productList){
this.mCtx=mCtx;
this.productList=productList;
}
@凌驾
公共产品ViewHolder onCreateViewHolder(视图组父级,int-viewType){
LayoutFlater充气机=LayoutFlater.from(mCtx);
视图=充气机。充气(R.layout.list\u布局,空);
返回新的ProductViewHolder(视图);
}
@凌驾
BindViewHolder上的公共无效(ProductViewHolder,int位置){
产品=产品列表。获取(位置);
holder.textViewType.setText(product.getType());
holder.textViewProperty.setText(product.getProperty());
holder.textViewMoreInfo.setText(String.valueOf(product.getMoreInfo());
holder.textViewDate.setText(String.valueOf(product.getDate());
//holder.imageView.setImageDrawable(mCtx.getResources().getDrawable(product.getImage());
}
@凌驾
public int getItemCount(){
返回productList.size();
}
类ProductViewHolder扩展了RecyclerView.ViewHolder{
图像视图图像视图;
TextView textViewType、textViewProperty、textViewMoreInfo、textViewDate;
公共产品视图持有者(视图项视图){
超级(项目视图);
imageView=itemView.findViewById(R.id.imageView);
textViewType=itemView.findViewById(R.id.textViewType);
textViewProperty=itemView.findViewById(R.id.textViewProperty);
textViewMoreInfo=itemView.findViewById(R.id.textViewMoreInfo);
textViewDate=itemView.findViewById(R.id.textViewDate);
}
}
}
活动

package com.example.benchalmers.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class Maintenance extends AppCompatActivity {

    private static final String PRODUCT_URL = "http://192.168.64.2/MyApi/api.php";

    RecyclerView recyclerView;
    private ProductAdapter adapter;

    List<Product> productList;

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

        productList = new ArrayList<>();

        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        this.adapter = new ProductAdapter(this, productList);
        recyclerView.setAdapter(adapter);

        loadProducts ();

    }

    private void loadProducts () {

        StringRequest stringRequest = new StringRequest(Request.Method.GET, PRODUCT_URL,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        try {
                            JSONArray products  =new JSONArray(response);

                            for (int i = 0; i<products.length(); i++){

                                JSONObject productObject = products.getJSONObject(i);

                                int maintenance_id = productObject.getInt("maintenance_id");
                                String type = productObject.getString("type");
                                String property = productObject.getString("property");
                                String more_info = productObject.getString("more_info");
                                Double date = productObject.getDouble("date");

                                Product product = new Product(maintenance_id, type, property, more_info, date);
                                productList.add(product);

                            }

                            adapter = new ProductAdapter(Maintenance.this, productList);
                            recyclerView.setAdapter(adapter);

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }

                    }
                },

                new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

                Toast.makeText(Maintenance.this, error.getMessage(), Toast.LENGTH_SHORT).show();

                    }
                });

        Volley.newRequestQueue(this).add(stringRequest);

    }
}
package com.example.benchalmers.myapplication;
导入android.support.v7.app.AppActivity;
导入android.os.Bundle;
导入android.support.v7.widget.LinearLayoutManager;
导入android.support.v7.widget.RecyclerView;
导入android.widget.Toast;
导入com.android.volley.Request;
导入com.android.volley.Response;
导入com.android.volley.VolleyError;
导入com.android.volley.toolbox.StringRequest;
导入com.android.volley.toolbox.volley;
导入org.json.JSONArray;
导入org.json.JSONException;
导入org.json.JSONObject;
导入java.util.ArrayList;
导入java.util.List;
公共类维护扩展了AppCompative活动{
私有静态最终字符串产品\u URL=”http://192.168.64.2/MyApi/api.php";
回收视图回收视图;
私有产品适配器;
列出产品清单;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maintenance);
productList=新的ArrayList();
recyclerView=(recyclerView)findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(新的LinearLayoutManager(本));
this.adapter=新产品适配器(this,productList);
recyclerView.setAdapter(适配器);
装载产品();
}
私有void loadProducts(){
StringRequest StringRequest=新的StringRequest(Request.Method.GET、PRODUCT\u URL、,
新的Response.Listener(){
@凌驾
公共void onResponse(字符串响应){
试一试{
JSONArray产品=新的JSONArray(响应);

对于(int i=0;i,如错误消息所述,您没有将任何
适配器
绑定到
回收视图
,因此它无法显示任何内容并“跳过布局”

当您使用
RecyclerView
创建一个应用程序,并且您已经编写了一个
适配器
,那么您还必须将该
适配器
附加到
RecyclerView
,这在您的代码中类似:

private ProductAdapter adapter;

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

    productList = new ArrayList<>();

    recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    this.adapter = new ProductAdapter(this, productList);
    recyclerView.setAdapter(adapter)

    loadProducts ();

}
私有产品适配器;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maintenance);
productList=新的ArrayList();
recyclerView=(recyclerView)findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(新的LinearLayoutManager(本));
this.adapter=新产品适配器(this,productList);
recyclerView.setAdapter(适配器)
装载产品();
}
有关RecyclerView的更多信息,请参阅Android开发者的页面


请注意,在
loadProducts();
中,请求完成后,您不能重新实例化适配器,而是调用
this.Adapter.notifyDataSetChanged();

你能像上面说的那样发布你的RecyclerView适配器和活动代码吗。你没有用
RecyclerView
附加适配器。你能在这里添加活动吗?添加适配器代码。在添加适配器的地方添加活动代码。这个错误不是来自适配器内部,你可以看到你是如何在中附加适配器的ode>StringRequest<