课后listview作业

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">

    <ListView
        android:id="@+id/good"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        tools:ignore="MissingConstraints"></ListView>

</androidx.constraintlayout.widget.ConstraintLayout>

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/imgood"
        android:layout_width="150dp"
        android:layout_height="131dp"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginStart="2dp"
        android:layout_marginTop="4dp"
        android:layout_weight="2"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="2dp"></ImageView>

    <TextView
        android:id="@+id/name"
        android:layout_width="255dp"
        android:layout_height="57dp"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginStart="157dp"
        android:layout_marginLeft="157dp"
        android:layout_marginTop="28dp"
        android:layout_marginEnd="-2dp"
        android:layout_marginRight="-2dp"
        android:layout_weight="3"
        android:text="TextView"
        android:textSize="20dp" />

    <TextView
        android:id="@+id/price"
        android:layout_width="253dp"
        android:layout_height="69dp"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginTop="95dp"
        android:layout_marginEnd="-5dp"
        android:layout_marginRight="-5dp"
        android:text="TextView"
        android:textSize="12dp" />

</RelativeLayout>

Goods

package com.example.listview;

public class Goods {
    private int id;
    private String name;
    private int price;
    private int imageId;

    public Goods() {
    }

    public Goods(String name, int price, int imageId) {
        this.name = name;
        this.price = price;
        this.imageId = imageId;
    }

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getImageId() {
        return imageId;
    }

    public void setImageId(int imageId) {
        this.imageId = imageId;
    }
}

MainActivity.java

package com.example.listview;

import androidx.appcompat.app.AppCompatActivity;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

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

public class MainActivity extends AppCompatActivity {
    List<Goods> list=new ArrayList<Goods>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ShopHelper shopHelper=new ShopHelper(this);
        SQLiteDatabase db = shopHelper.getReadableDatabase();
        Cursor cursor = db.rawQuery("select * from goodinfo", null);
        if (cursor.getCount() != 0) {
            while (cursor.moveToNext()) {
//                s += cursor.getInt(0) + "   " + cursor.getString(1) + "   "
//                        + cursor.getInt(2) + "\n";
                Goods goods=new Goods();
                goods.setId(cursor.getInt(0));
                goods.setName(cursor.getString(1));
                goods.setPrice(cursor.getInt(2));
                goods.setImageId(R.drawable.good);
                list.add(goods);
                ListView lv=(ListView) findViewById(R.id.good);
                lv.setAdapter(new myadapter());
            }
        }

    }
    private class myadapter extends BaseAdapter{

        @Override
        public int getCount() {
            return list.size();
        }

        @Override
        public Object getItem(int i) {
            return null;
        }

        @Override
        public long getItemId(int i) {
            return 0;
        }

        @Override
        public View getView(int i, View view, ViewGroup viewGroup) {
            View view2 = View.inflate(MainActivity.this, R.layout.list_item, null);
            TextView name=(TextView)view2.findViewById(R.id.name);
            TextView price=(TextView)view2.findViewById(R.id.price);
            ImageView image = (ImageView) view2.findViewById(R.id.imgood);
            name.setText(list.get(i).getName());
            price.setText(list.get(i).getPrice()+"");
            image.setImageResource(R.drawable.good);
            return view2;
        }
    }
}

ShopHelper

package com.example.listview;

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

import androidx.annotation.Nullable;

public class ShopHelper extends SQLiteOpenHelper {
    public ShopHelper(@Nullable Context context) {
        super(context, "Goods.db", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        sqLiteDatabase.execSQL("create table goodinfo(_id integer primary key autoincrement,name varchar(20),price integer)");
        sqLiteDatabase.execSQL("insert into goodinfo (name,price) values('香蕉',10)");
        sqLiteDatabase.execSQL("insert into goodinfo (name,price) values('苹果',20)");
        sqLiteDatabase.execSQL("insert into goodinfo (name,price) values('西瓜',30)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }
}