Android實現商品展示效果

2019-10-23 18:28:37

字體：大中小

來源：轉載

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一、創建手機界面布局

創建一個activity_main.xml文件代碼如下：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.bz0209.shopshowdemo.activity_main" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <EditText android:id="@+id/etName" android:layout_width="wrap_content" android:layout_height="wrap_content" android:hint="商品名稱" android:inputType="text" android:layout_weight="1" /> <EditText android:id="@+id/etAmount" android:layout_width="wrap_content" android:layout_height="wrap_content" android:hint="商品金額" android:inputType="number" android:layout_weight="1" /> <ImageView android:id="@+id/ivAdd" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="addGoods" android:inputType="text" android:src="@android:drawable/ic_input_add" /> </LinearLayout> <ListView android:id="@+id/lvGoods" android:layout_width="match_parent" android:layout_height="match_parent"> </ListView></LinearLayout>

效果圖如下：

Android,商品展示

二、創建一個存儲展示的xml文件

創建一個名為item.xml的布局文件，代碼如下：

<?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="match_parent"> <TextView android:text="1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tvId" android:textSize="20sp" android:layout_weight="2" /> <TextView android:text="商品名稱" android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tvName" android:textSize="20sp" android:layout_weight="2" /> <TextView android:text="金額" android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tvAmount" android:textSize="20sp" android:layout_weight="2" /> <ImageView  android:id="@+id/ivUP"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:src="@android:drawable/arrow_up_float"  /> <ImageView  android:id="@+id/ivDown"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:src="@android:drawable/arrow_down_float"  /> <ImageView  android:id="@+id/ivDelete"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:src="@android:drawable/arrow_down_float"  /></LinearLayout>

三、創建數據庫

在com.example.bz0209.shopshowdemo 的包下創建一個名為db的包，并在該包下定義一個dbHelper類繼承自SQLiteOpenHelper，創建數據庫代碼如下：

package com.example.bz0209.shopshowdemo.db;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;/** * Created by Administrator on 2017/4/28. */public class DBHelper extends SQLiteOpenHelper{ public static final String CREATE_GOODS="create table goods(_id integer primary key autoincrement,name varchar(20),amount integer)"; public DBHelper(Context context,int version){ super(context,"goods.db",null,version); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(CREATE_GOODS); } @Override public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion) { }}

四、創建GoodsAdapter類

為了操作數據庫方便，創建一個GoodsAdapter類。因此需要在com.example.bz0209.shopshowdemo 的包下創建一個名為entity的包，然后在com.example.bz0209.shopshowdemo.entityd的包下定義一個GoodsAdapter類，代碼如下：

package com.example.bz0209.shopshowdemo;import android.content.Context;import android.support.annotation.NonNull;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.ImageView;import android.widget.TextView;import com.example.bz0209.shopshowdemo.entity.Goods;import java.util.List;/** * Created by Administrator on 2017/4/27. */public class GoodsAdapter extends ArrayAdapter<Goods>{ private int resounceId; public GoodsAdapter(Context context, int resource, List<Goods> objects) { super(context, resource, objects); resounceId=resource; } @NonNull @Override public View getView(int position, View convertView, ViewGroup parent) { Goods goods=getItem(position); View view=null; ViewHolder viewHolder; if (convertView==null){  view = LayoutInflater.from(getContext()).inflate(resounceId,null);  viewHolder =new ViewHolder();  viewHolder.tvId=(TextView) view.findViewById(R.id.tvId);  viewHolder.tvName=(TextView) view.findViewById(R.id.tvName);  viewHolder.tvAmount=(TextView) view.findViewById(R.id.etAmount);  viewHolder.ivUp=(ImageView) view.findViewById(R.id.ivUP);  viewHolder.ivDown=(ImageView) view.findViewById(R.id.ivDown);  viewHolder.ivDelete=(ImageView) view.findViewById(R.id.ivDelete);  view.setTag(viewHolder); }else {  view=convertView;  viewHolder=(ViewHolder) view.getTag(); } viewHolder.tvId.setText(goods.getId()+""); viewHolder.tvName.setText(goods.getName()); viewHolder.tvAmount.setText(goods.getAmount()+""); return view; } class ViewHolder{ TextView tvId; TextView tvName; TextView tvAmount; ImageView ivUp; ImageView ivDown; ImageView ivDelete; }}

五、創建數據操作邏輯類

在com.example.bz0209.shopshowdemo 的包下創建一個名為dao的包，并創建一個名為GoodsDao的類，用于操作數據。代碼如下：

public class GoodsDao { private DBHelper dbHelper; public GoodsDao(Context context){ dbHelper=new DBHelper(context,1); } public void add(Goods goods){ SQLiteDatabase sqLiteDatabase=dbHelper.getWritableDatabase(); ContentValues values=new ContentValues(); values.put("name",goods.getName()); values.put("amount",goods.getAmount()); sqLiteDatabase.insert("goods",null,values); sqLiteDatabase.close(); } public int delete(long id){ SQLiteDatabase sqLiteDatabase=dbHelper.getWritableDatabase(); int count=sqLiteDatabase.delete("goods","id=?",new String[]{id+""}); sqLiteDatabase.close(); return count; } public int update(Goods goods){ SQLiteDatabase sqLiteDatabase=dbHelper.getWritableDatabase(); ContentValues values=new ContentValues(); values.put("name",goods.getName()); values.put("amount",goods.getAmount()); int count=sqLiteDatabase.update("goods",values,"id=?",new String[]{goods.getId()+""}); sqLiteDatabase.close(); return count; } public List<Goods> queryAll(){ List<Goods>goodsList=new ArrayList<>(); SQLiteDatabase sqLiteDatabase=dbHelper.getReadableDatabase(); Cursor cursor=sqLiteDatabase.query("goods",null,null,null,null,null,"amount desc"); while (cursor.moveToNext()){  long id=cursor.getLong(cursor.getColumnIndex("_id"));  String name=cursor.getString(cursor.getColumnIndex("name"));  int amount=cursor.getInt(cursor.getColumnIndex("amount"));  Goods goods=new Goods(name,amount);  goodsList.add(goods); } cursor.close(); sqLiteDatabase.close(); return goodsList; }}

六、編寫界面交互代碼

數據庫操作完成后，需要界面與數據庫進行交互，用于實現將數據庫中的數據以ListView的形式展現在界面上具體代碼如下：

package com.example.bz0209.shopshowdemo;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.EditText;import android.widget.ListView;import com.example.bz0209.shopshowdemo.dao.GoodsDao;import com.example.bz0209.shopshowdemo.entity.Goods;import java.util.List;public class activity_main extends AppCompatActivity { private EditText etName; private EditText etAmount; private ListView lvGoods; private GoodsAdapter goodsAdapter; private GoodsDao goodsDao; private List<Goods>goodsList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); etName=(EditText)findViewById(R.id.etName); etAmount=(EditText)findViewById(R.id.etAmount); lvGoods=(ListView)findViewById(R.id.lvGoods); goodsDao=new GoodsDao(this); goodsList=goodsDao.queryAll(); goodsAdapter=new GoodsAdapter(this,R.layout.item,goodsList); lvGoods.setAdapter(goodsAdapter); } public void addGoods(View view){ String name=etName.getText().toString(); String amount=etAmount.getText().toString(); Goods goods=new Goods(name,amount.equals("")?0:Integer.parseInt(amount)); goodsDao.add(goods); }}

七、完成后的結果展示

（1）創建起數據庫的圖為：

Android,商品展示