Android基础知识【项目实训】【五】

Android基础知识【项目实训】【5】

【该项目实训是Android基础知识的一个综合练习，特别提示：项目中会用到一些图片素材，都是随意整理的，稍后会上传一个资源，包含该事项项目的基本功能，也含有图片素材】

【目标】

主界面中包含两个二级子界面，分别是活动界面和账单界面，下面介绍它们的实现代码和布局文件。

1、下面这个是 活动界面的Activity代码，因为这个界面加载时需要 读取数据库中数据了，所有功能的实现上会涉及到 db那个包中一些类。

注意这个Activity也是继承 ActivityGroup的

public class DiscountFoodActivity extends ActivityGroup implements OnItemClickListener {	TabHost innerTab;	ListView promotionFoodList,discountFoodList;	//促销列表数据，	List<FoodInfo> pdata;	//折扣列表数据	List<FoodInfo> ddata;	@Override	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_discount_food);		promotionFoodList=(ListView) findViewById(R.id.promotionFoodList);		discountFoodList=(ListView) findViewById(R.id.discountFoodList);		innerTab=(TabHost) findViewById(R.id.innerTab_discount);		//初始化的内部Tab		initInnerTabHost();		initListView();	//初始化列表数据		//添加监听器，监听列表项的点击		promotionFoodList.setOnItemClickListener(this);		discountFoodList.setOnItemClickListener(this);	}	//初始化活动食品列表 和 折扣食品列表	private void initListView() {		//获取数据库		EatDbHelper dbh=new EatDbHelper(this,"fooddb.db3",null,1);		SQLiteDatabase db =dbh.getReadableDatabase(); 		pdata =new FoodDao().queryFood(db, 				"ispromotion=?", new String[]{"1"}, "price DESC");		FoodListAdapter fla =new FoodListAdapter(				this,pdata,R.layout.foodlist_item); 		promotionFoodList.setAdapter(fla);				ddata =new FoodDao().queryFood(db, 				"discount<?", new String[]{"1"}, "price DESC");		fla =new FoodListAdapter(				this,ddata,R.layout.foodlist_item); 		discountFoodList.setAdapter(fla);			}	private void initInnerTabHost() {		innerTab.setup(getLocalActivityManager());		TabSpec t1=innerTab.newTabSpec("inner_dis_t1");		t1.setIndicator("今日活动", getResources().getDrawable(R.drawable.ic_launcher));		t1.setContent(R.id.innerTab_discount_tab1);				TabSpec t2=innerTab.newTabSpec("inner_dis_t2");		t2.setIndicator("今日折扣", getResources().getDrawable(R.drawable.ic_launcher));		t2.setContent(R.id.innerTab_discount_tab2);				innerTab.addTab(t1);		innerTab.addTab(t2);	}	@Override	public boolean onCreateOptionsMenu(Menu menu) {		// Inflate the menu; this adds items to the action bar if it is present.		getMenuInflater().inflate(R.menu.discount_food, menu);		return true;	}	@Override	public void onItemClick(AdapterView<?> lv, View view, int index, long arg3) {		Intent intent =new Intent(this,FoodDetailActivity.class);		Bundle bd =new Bundle();		//Log.i("Msg", "当前点击列表"+lv + "  "+lv.getId());		if(lv.getId()==R.id.promotionFoodList){			bd.putSerializable("food",pdata.get(index));			//Log.i("Msg", "当前选择："+pdata.get(index).getFoodName());		}else if(lv.getId()==R.id.discountFoodList){			bd.putSerializable("food",ddata.get(index));			//Log.i("Msg", "当前选择："+ddata.get(index).getFoodName());		}		intent.putExtras(bd);		startActivity(intent);	}}

2、布局界面，项目中用到很多资源，现在把这些资源的结果 展示一下。

活动Activity使用的界面是activity_discount_food.xml，代码是：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".DiscountFoodActivity" >    <TabHost        android:id="@+id/innerTab_discount"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true" >        <LinearLayout            android:layout_width="match_parent"            android:layout_height="match_parent"            android:orientation="vertical" >            <TabWidget                android:id="@android:id/tabs"                android:layout_width="match_parent"                android:layout_height="wrap_content" >            </TabWidget>            <FrameLayout                android:id="@android:id/tabcontent"                android:layout_width="match_parent"                android:layout_height="match_parent" >                <LinearLayout                    android:id="@+id/innerTab_discount_tab1"                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:orientation="vertical"                     >                     <ListView                         android:id="@+id/promotionFoodList"                         android:layout_width="match_parent"                         android:layout_height="match_parent"                         >                     </ListView>                </LinearLayout>                <LinearLayout                    android:id="@+id/innerTab_discount_tab2"                    android:layout_width="match_parent"                    android:orientation="vertical"                    android:layout_height="match_parent" >                    <ListView                         android:id="@+id/discountFoodList"                         android:layout_width="match_parent"                         android:layout_height="match_parent"                         >                     </ListView>                </LinearLayout>            </FrameLayout>        </LinearLayout>    </TabHost></RelativeLayout>

其实这也是一个tab导航，只是它的标签导航在上面。
3、因为要读取活动和折扣 食物数据，因此准备了两个集合

//促销列表数据，	List<FoodInfo> pdata;	//折扣列表数据	List<FoodInfo> ddata;

这里的FoodInf是一个实体类，请留意对属性的注释。

package com.example.entity;import java.io.Serializable;import android.graphics.Bitmap;public class FoodInfo implements Serializable {	private String _id,foodName;	private String price;	private String isPromotion;	//菜品是否促销活动 1 有活动， 0 没有活动	private String discount="1";	//折扣	private String category;	//食物所属类别，主食、配菜、饮料，其他四类	private String type;	//菜系，酸甜苦辣咸等，鲁粤川苏等	private String score;	//菜品累计得分	private int shopId;	//餐馆ID	private ShopInfo shop;	//食物所属餐馆	private Bitmap img;		private String imgId;	private String description;	//关于食物的描述		public String getFoodName() {		return foodName;	}	public void setFoodName(String foodName) {		this.foodName = foodName;	}	public String getPrice() {		return price;	}	public void setPrice(String price) {		this.price = price;	}	public String getCategory() {		return category;	}	public void setCategory(String category) {		this.category = category;	}	public String getType() {		return type;	}	public void setType(String type) {		this.type = type;	}	public String getScore() {		return score;	}	public void setScore(String score) {		this.score = score;	}	public ShopInfo getShop() {		return shop;	}	public void setShop(ShopInfo shop) {		this.shop = shop;	}	public String get_id() {		return _id;	}	public void set_id(String _id) {		this._id = _id;	}	public int getShopId() {		return shopId;	}	public void setShopId(int shopId) {		this.shopId = shopId;	}	public String getIsPromotion() {		return isPromotion;	}	public void setIsPromotion(String isPromotion) {		this.isPromotion = isPromotion;	}	public String getDiscount() {		return discount;	}	public void setDiscount(String discount) {		this.discount = discount;	}	public Bitmap getImg() {		return img;	}	public void setImg(Bitmap img) {		this.img = img;	}	public String getImgId() {		return imgId;	}	public void setImgId(String imgId) {		this.imgId = imgId;	}	public String getDescription() {		return description;	}	public void setDescription(String description) {		this.description = description;	}	@Override	public String toString() {		return "FoodInfo [_id=" + _id + ", foodName=" + foodName + ", price="				+ price + ", isPromotion=" + isPromotion + ", discount="				+ discount + ", category=" + category + ", type=" + type				+ ", score=" + score + ", shopId=" + shopId + ", shop=" + shop				+ ", img=" + img + ", imgId=" + imgId + "]";	}	}

4、上面的俩集合中的数据是靠 db中的类给填充的。

pdata =new FoodDao().queryFood(db, 				"ispromotion=?", new String[]{"1"}, "price DESC");

FoodDao就是一个专门读取 食物数据的类，其代码如下：

public class FoodDao {	public List<FoodInfo> queryFood(SQLiteDatabase db,String sel,String []selArg,String order){		List<FoodInfo> fs=new ArrayList<FoodInfo>();		Cursor c=db.query("tb_foodInfo",				new String[]{"_id","foodName","category","type","price",				"score","imgId","shopId","discount","isPromotion"}, 				sel,selArg,null,null,order);		Log.i("Msg", "读取记录条数 ："+c.getCount());		c.moveToFirst();		while(!c.isAfterLast()){			FoodInfo f =new FoodInfo();			f.set_id(c.getString(0));			f.setFoodName(c.getString(1));			f.setCategory(c.getString(2));			f.setType(c.getString(3));			f.setPrice(c.getString(4));			f.setScore(c.getString(5));			String imgId=c.getString(6);			f.setImgId(Integer.parseInt(imgId.substring(2),16)+"");			f.setShopId(c.getInt(7));			f.setDiscount(c.getString(8));			f.setIsPromotion(c.getString(9));			//Log.i("Msg", f.toString());			fs.add(f);			c.moveToNext();		}		c.close();		return fs;	}	}

5、读取完数据了，就可以采用适配器 把数据绑定到 列表上了。

FoodListAdapter fla =new FoodListAdapter(
this,pdata,R.layout.foodlist_item); 

FoodListAdapter是一个继承了BaseAdapter的适配器。（   容易理解期间，这个适配器写的并不通用，但应该容易理解了）

代码如下：

public class FoodListAdapter extends BaseAdapter {	private Context context;	private List<FoodInfo> data;	private int layout;		public FoodListAdapter(Context context, List<FoodInfo> data, int layout) {		super();		this.context = context;		this.data = data;		this.layout = layout;	}	@Override	public int getCount() {		return data.size();	}	@Override	public Object getItem(int arg0) {		// TODO Auto-generated method stub		return data.get(arg0);	}	@Override	public long getItemId(int arg0) {		// TODO Auto-generated method stub		return arg0;	}	@Override	public View getView(int index, View arg1, ViewGroup arg2) {		LayoutInflater inflater =LayoutInflater.from(context);		View v =inflater.inflate(layout, null);		ImageView iv =(ImageView) v.findViewById(R.id.foodlist_item_img);		iv.setImageResource(Integer.parseInt(data.get(index).getImgId()));		TextView name=(TextView) v.findViewById(R.id.foodlist_item_name);		name.setText(data.get(index).getFoodName());		TextView category=(TextView) v.findViewById(R.id.foodlist_item_category);		category.setText(data.get(index).getCategory());		TextView type=(TextView) v.findViewById(R.id.foodlist_item_type);		type.setText(data.get(index).getType());		TextView price=(TextView) v.findViewById(R.id.foodlist_item_price);		price.setText("￥"+data.get(index).getPrice());		float zk =Float.parseFloat(data.get(index).getDiscount());		if(zk<1){			TextView discount=(TextView) v.findViewById(R.id.foodlist_item_discount);			discount.setText("折扣:"+(zk*10)+"折");		}		TextView score=(TextView) v.findViewById(R.id.foodlist_item_score);		score.setText("百米分:"+data.get(index).getScore()+"米");		return v;	}}

6、其中 列表

ListView promotionFoodList,discountFoodList;

它们的列表项布局是一样的，统一采用布局文件：

<pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent" >    <ImageView        android:id="@+id/foodlist_item_img"        android:layout_width="60dp"        android:layout_height="60dp"        android:background="@drawable/imgbg"        android:src="@drawable/food_02" />    <TextView        android:id="@+id/foodlist_item_name"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@id/foodlist_item_img"        android:layout_marginLeft="8dp"        android:text="菜品"        android:textAppearance="?android:attr/textAppearanceLarge" />    <TextView        android:id="@+id/foodlist_item_category"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@id/foodlist_item_name"        android:layout_marginLeft="8dp"        android:text="中餐"        android:textAppearance="?android:attr/textAppearanceMedium" />    <TextView        android:id="@+id/foodlist_item_type"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@id/foodlist_item_category"        android:layout_marginLeft="8dp"        android:text="酸辣"        android:textAppearance="?android:attr/textAppearanceMedium" />    <TextView        android:id="@+id/foodlist_item_price"        android:layout_width="wrap_content"        android:layout_height="wrap_content"		android:layout_below="@id/foodlist_item_name"		android:layout_alignLeft="@id/foodlist_item_name"        android:layout_marginTop="8dp"        android:text="￥10.00"        android:textAppearance="?android:attr/textAppearanceSmall" />    <TextView        android:id="@+id/foodlist_item_discount"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@id/foodlist_item_price"        android:layout_alignBottom="@id/foodlist_item_price"        android:layout_marginLeft="8dp"        android:text=""        android:textAppearance="?android:attr/textAppearanceSmall" />    <TextView        android:id="@+id/foodlist_item_score"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@id/foodlist_item_discount"        android:layout_alignBottom="@id/foodlist_item_discount"		android:layout_alignParentRight="true"		android:layout_marginRight="8dp"		android:gravity="right"                android:text="评分：122"        android:textAppearance="?android:attr/textAppearanceSmall" />	</RelativeLayout>

折扣界面说完，下一篇说 账单界面。