Question

我正在尝试创建字典应用程序，但是当我运行该应用程序运行时，却收到“复制失败”吐司，并且在日志中，我发现此错误“ E / RecyclerView：未连接适配器；跳过布局” 。请在我的代码下方找到此处，并提供屏幕截图。我已经放置了SQLite file in the assets folder。您能帮我解决这个问题吗？

最好的问候，拉明

这是我的Word_Adapter类代码

package com.example.androiddictionarywithsqlite.adapters;

import android.content.Context;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.example.androiddictionarywithsqlite.DictionaryModel;
import com.example.androiddictionarywithsqlite.R;

import java.util.List;

public class Word_Adapter extends RecyclerView.Adapter<Word_Adapter.ViewHolder> {

    public List<DictionaryModel> data;

    public Word_Adapter(){}
    public void setData(List<DictionaryModel>data) {
        this.data = data;
    }
    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {

        Context context = viewGroup.getContext();
        LayoutInflater inflater = LayoutInflater.from(context);
        View wordView = inflater.inflate(R.layout.word_item,viewGroup,false);
        ViewHolder viewHolder = new ViewHolder(wordView,context);
        return viewHolder;
    }

    public void onBindViewHolder(@NonNull ViewHolder viewHolder, int position) {
        DictionaryModel dictionaryModel = data.get(position);
        viewHolder.wordText.setText(dictionaryModel.getWord());

    }

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

    public class ViewHolder extends RecyclerView.ViewHolder{
        public Context context;
        public TextView wordText;

        public ViewHolder(View itemView, final Context context) {
            super(itemView);
            this.context = context;
            wordText = (TextView) itemView.findViewById(R.id.wordtext);
        }
    }
}

这是我的MainActivity类代码

public class MainActivity extends AppCompatActivity {
    private RecyclerView rvWord;
    private Word_Adapter word_adapter;
    private List<DictionaryModel> dictionaryModelList;
    private DatabaseHelper mDBHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        rvWord = (RecyclerView) findViewById(R.id.rvWord);
        rvWord.setLayoutManager(new LinearLayoutManager(getApplicationContext()));

        mDBHelper = new DatabaseHelper(this);
        File database=getApplicationContext().getDatabasePath(DatabaseHelper.DBNAME);
        if (database.exists()== false){
            mDBHelper.getReadableDatabase();
            if(copyDatabase(this)){
                Toast.makeText(getApplicationContext(),"copy successful",Toast.LENGTH_LONG).show();
            }else {
                Toast.makeText(getApplicationContext(),"copy failed",Toast.LENGTH_LONG).show();
                return;
            }
        }

        dictionaryModelList=mDBHelper.getlistWord("");
        word_adapter = new Word_Adapter();
        word_adapter.setData(dictionaryModelList);
        rvWord.setAdapter(word_adapter);

    }

    private boolean copyDatabase(Context context) {
        try{
            InputStream inputStream = context.getAssets().open(DatabaseHelper.DBNAME);
            String outFileName=DatabaseHelper.DBLOCATION + DatabaseHelper.DBNAME;
            OutputStream outputStream = new FileOutputStream(outFileName);
            byte[]buff= new byte[1024];
            int length = 0;
            while ((length=inputStream.read(buff))>0){
                outputStream.write(buff,0,0);
            }
            outputStream.flush();
            outputStream.close();
            Log.w("Database","copy successfully");
            return true;


        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }

}

这是我的DatabaseHelper calss代码

public class DatabaseHelper extends SQLiteOpenHelper {
    public static final String DBNAME = "mydictionary.sqlite";
    public static final String DBLOCATION = "/data/data/com.example.androiddictionarywithsqlite/database/";
    private Context mcontext;
    private SQLiteDatabase mDatabase;

    public DatabaseHelper(Context context){
        super(context,DBNAME,null,1);
        this.mcontext=context;


    }

    @Override
    public void onCreate(SQLiteDatabase db) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }

    public void openDatabase(){
        String dbPath=mcontext.getDatabasePath(DBNAME).getPath();
        if (mcontext!=null && mDatabase.isOpen()){
            return;
        }
        mDatabase=SQLiteDatabase.openDatabase(dbPath,null,SQLiteDatabase.OPEN_READWRITE);
    }
    public void closeDatabase(){
        if(mDatabase!=null){
            mDatabase.close();
        }
    }
    public List<DictionaryModel> getlistWord(String wordSearch){
        DictionaryModel dictionaryModel = null;
        List<DictionaryModel> dictionaryModelList = new ArrayList<>();
        openDatabase();
        String[] args={"%"+wordSearch+"%"};

        Cursor cursor= mDatabase.rawQuery("Select * From tblWord Where word Like ?",args);
        cursor.moveToFirst();
        while(!cursor.isAfterLast()){
           dictionaryModel = new DictionaryModel(cursor.getString(0),cursor.getString(1),cursor.getString(2));
           dictionaryModelList.add(dictionaryModel);
           cursor.moveToNext();
        }
        cursor.close();
        closeDatabase();
        return dictionaryModelList;
    }
}

这是我的DictionaryModel类的代码

package com.example.androiddictionarywithsqlite;

public class DictionaryModel {
    private String id;
    private String word;
    private String definition;

    public DictionaryModel(String id, String word, String definition) {
        this.id = id;
        this.word = word;
        this.definition = definition;
    }

    public String getId() {
        return id;
    }

    public String getWord() {
        return word;
    }

    public String getDefinition() {
        return definition;
    }

    public void setId(String id) {
        this.id = id;
    }

    public void setWord(String word) {
        this.word = word;
    }

    public void setDefinition(String definition) {
        this.definition = definition;
    }

}

这是activity_main的Xlm代码

<?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=".MainActivity">


    <android.support.v7.widget.SearchView
        android:id="@+id/searchView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:iconifiedByDefault="false"
        app:queryHint="Search"
        />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rvWord"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/searchView"
        />
</RelativeLayout>

这是word_item的xml代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="8dp"
    android:background="@android:color/transparent"
    android:foreground="?android:attr/selectableItemBackground"
    >

    <TextView
        android:id="@+id/wordText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="40sp"
        />

</LinearLayout>

screen shot

复制数据库失败，祝酒/ RecyclerView：未连接适配器；跳过布局”

0 个答案: