SQLite 辞典实例

image.png image.png

<?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">

    <TextView
        android:textSize="80sp"
        android:layout_marginTop="20dp"
        android:text="       辞典"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <EditText
        android:textSize="14sp"
        android:id="@+id/editText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="30dp"
        android:layout_marginRight="30dp"
        android:layout_marginTop="160dp"
        />

    <Button
        android:text="翻译"
        android:id="@+id/btn_fanyi"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/editText"
        android:layout_marginTop="90dp"
        android:layout_marginRight="30dp"
        android:layout_alignParentRight="true"
        />
    
    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="10dp"
        android:layout_below="@id/btn_fanyi"
        android:layout_marginTop="40dp"
        >
    </ListView>

    <Button
        android:text="添加新词"
        android:id="@+id/btn_tianjia"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/listView"
        android:layout_marginRight="30dp"
        android:layout_alignParentRight="true"
        android:layout_marginTop="20dp"
        />
    <TextView
        android:textSize="20dp"
        android:layout_marginTop="20dp"
        android:id="@+id/xianshi"
        android:layout_width="150dp"
        android:layout_height="wrap_content"
        android:layout_below="@id/listView"
        />
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".addActivity"
    android:layout_marginRight="20dp"
    android:layout_marginLeft="20dp"
    >

    <EditText
        android:layout_marginTop="150dp"
        android:id="@+id/ed_danci"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <EditText
        android:id="@+id/ed_jiexi"
        android:layout_marginTop="100dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:textSize="30sp"
        android:text="确定"
        android:layout_marginTop="200dp"
        android:id="@+id/btn_ok"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <Button
        android:layout_marginTop="20dp"
        android:textSize="30sp"
        android:text="取消"
        android:id="@+id/btn_cancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

import android.content.Intent;
import android.database.Cursor;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

public class MainActivity extends AppCompatActivity {

    private DBOpenHelper dbOpenHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //实例化DBOpenHelper对象用来创建数据库
        dbOpenHelper=new DBOpenHelper(MainActivity.this,"db_dict",null,1);
        
        final ListView listView=findViewById(R.id.listView);
        final EditText editText=findViewById(R.id.editText);
        Button btn_fanyi=findViewById(R.id.btn_fanyi);
        Button btn_tianjia=findViewById(R.id.btn_tianjia);
        final TextView xianshi=findViewById(R.id.xianshi);
        
        btn_fanyi.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                String key=editText.getText().toString();//获取要查询的单词
                //执行查询操作
                Cursor cursor=dbOpenHelper.getReadableDatabase().query("tb_dict",null,"word=?"
                        ,new String[]{key},null,null,null);

                //创建ArrayList对象用于保存查询结果
                ArrayList<Map<String,String>> resultList=new ArrayList<Map<String, String>>();
                while(cursor.moveToNext()){
                    Map<String,String>map=new HashMap<String, String>();
                    map.put("word",cursor.getString(1));
                    map.put("interpret",cursor.getString(2));
                    resultList.add(map);
                }

                if(resultList==null||resultList.size()==0){
                    //提示没有相关信息
                    Toast.makeText(MainActivity.this, "没有相关信息", Toast.LENGTH_SHORT).show();
                }else{
//                    SimpleAdapter simpleAdapter=new SimpleAdapter(MainActivity.this,resultList,
//                            R.id.result_main,R.id.result_interpret);
                    String result=resultList.toString();
                    xianshi.setText(result);
                }
            }
        });
        //跳转到添加页面
        btn_tianjia.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(MainActivity.this,addActivity.class);
                startActivity(intent);
            }
        });
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if(dbOpenHelper!=null){
            dbOpenHelper.close();//关闭数据库连接
        }
    }
}

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DBOpenHelper extends SQLiteOpenHelper {
    //创建数据表的SQL语句
    final String CREATE_TABLE_SQL="create table tb_dict (_id integer primary key autoincrement,word,detail)";

    public DBOpenHelper(Context context, String name,  SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, null, version);


    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        //创建单词的数据表
        db.execSQL(CREATE_TABLE_SQL);

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        //数据库版本更新
        Log.i("辞典","--版本更新"+oldVersion+"-->"+newVersion);
    }
}

import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class addActivity extends AppCompatActivity {

    private DBOpenHelper dbOpenHelper;

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

        Button btn_ok=findViewById(R.id.btn_ok);
        Button btn_cancel=findViewById(R.id.btn_cancel);
        final EditText ed_danci=findViewById(R.id.ed_danci);
        final EditText ed_jiexi=findViewById(R.id.ed_jiexi);
        //实例化DBOpenHelper对象
        dbOpenHelper=new DBOpenHelper(addActivity.this,"db_dict",null,1);
        
        btn_ok.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String danci=ed_danci.getText().toString();//获取单词
                String jiexi=ed_jiexi.getText().toString();
                if(danci.equals("")||jiexi.equals("")){
                    Toast.makeText(addActivity.this, "生词或解析为空，请重新输入", Toast.LENGTH_SHORT).show();
                }else {
                    insertData(dbOpenHelper.getReadableDatabase(),danci,jiexi);
                    Toast.makeText(addActivity.this, "添加成功", Toast.LENGTH_SHORT).show();
                }
            }
        });

        btn_cancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //实现由副页面跳转回主页面
                Intent intent=new Intent(addActivity.this,MainActivity.class);
                startActivity(intent);
            }
        });
    }
    //插入数据的方法
    private void insertData(SQLiteDatabase sqLiteDatabase,String word,String interpret){

        ContentValues values=new ContentValues();
        values.put("word",word);
        values.put("detail",interpret);
        sqLiteDatabase.insert("tb_dict",null,values);
    }
    @Override
    protected void onDestroy() {
        if(dbOpenHelper!=null){
            dbOpenHelper.close();
        }
        super.onDestroy();
    }
}