Android实现购物车整体页面逻辑详解

public class MainActivity extends AppCompatActivity implements View.OnClickListener{  String url = "http://www.zhaoapi.cn/product/getCarts";  private ExpandableListView el_cart;  private CheckBox cb_cart_all_select;  private TextView tv_cart_total_price;  private Button btn_cart_pay;  MyAdapter adapter;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    initView();    initData();  }  private void initData() {    HashMap<String, String> map = new HashMap<>();    map.put("uid","71");    OkhtttpUtils.getInstance().doPost(url, map, new OkhtttpUtils.OkCallback() {      @Override      public void onFailure(Exception e) {      }      @Override      public void onResponse(String json) {        CartInfo cartInfo = new Gson().fromJson(json, CartInfo.class);        if ("0".equals(cartInfo.getCode())){          List<CartInfo.DataBean> data = cartInfo.getData();          adapter = new MyAdapter(data);          el_cart.setAdapter(adapter);          //展开二级列表          for(int x=0; x<data.size(); x++){            el_cart.expandGroup(x);          }          adapter.setOnCartListChangeListener(new MyAdapter.onCartListChangeListener() {            @Override            public void onSellerCheckedChange(int i) {              //商家被点击              boolean currentSellerAllProductSelected = adapter.isCurrentSellerAllProductSelected(i);              adapter.changeCurrentSellerAllProductsStatus(i, !currentSellerAllProductSelected);              adapter.notifyDataSetChanged();              //B.刷新底部数据              refreshSelectedAndTotalPriceAndTotalNumber();            }            @Override            public void onProductCheckedChange(int i, int i1) {              //点击商品得checkbox              adapter.changeCurrentProductStatus(i,i1);              adapter.notifyDataSetChanged();              //B.刷新底部数据              refreshSelectedAndTotalPriceAndTotalNumber();            }            @Override            public void onProducNumberChange(int i, int i1, int number) {              //当加减被点击              adapter.changeCurrentProductNumber(i,i1,number);              adapter.notifyDataSetChanged();              //B.刷新底部数据              refreshSelectedAndTotalPriceAndTotalNumber();            }          });        }      }    });  }  //B.刷新checkbox状态和总价和总数量  private void refreshSelectedAndTotalPriceAndTotalNumber() {    //去判断是否所有得商品都被选中    boolean allProductsSelected = adapter.isAllProductsSelected();    //设置给全选checkBox    cb_cart_all_select.setChecked(allProductsSelected);    //计算总价    float totalPrice = adapter.calculateTotalPrice();    tv_cart_total_price.setText("总价 " + totalPrice);    //计算总数量    int totalNumber = adapter.calculateTotalNumber();    btn_cart_pay.setText("去结算(" + totalNumber + ")");  }  //初始化的操作  private void initView() {    el_cart = (ExpandableListView) findViewById(R.id.el_cart);    cb_cart_all_select = (CheckBox) findViewById(R.id.cb_cart_all_select);    tv_cart_total_price = (TextView) findViewById(R.id.tv_cart_total_price);    btn_cart_pay = (Button) findViewById(R.id.btn_cart_pay);    cb_cart_all_select.setOnClickListener(this);  }  @Override  public void onClick(View view) {    switch (view.getId()){      case R.id.cb_cart_all_select:        //底部全选按钮        //时候所有得商品都被选中        boolean allProductsSelected = adapter.isAllProductsSelected();        adapter.changeAllProductStatus(!allProductsSelected);        adapter.notifyDataSetChanged();        //刷新底部数据        refreshSelectedAndTotalPriceAndTotalNumber();        break;    }  }}

public class MyAdapter extends BaseExpandableListAdapter{  private List<CartInfo.DataBean> list;  public MyAdapter(List<CartInfo.DataBean> data) {    list=data;  }  @Override  public int getGroupCount() {    return list==null ? 0 : list.size();  }  @Override  public int getChildrenCount(int i) {    return list.get(i).getList()==null ? 0 :list.get(i).getList().size();  }  @Override  public View getGroupView(final int i, boolean b, View view, ViewGroup viewGroup) {    //先拿到Bean里组的数据,看hiJson    CartInfo.DataBean dataBean = list.get(i);    ParentViewHolder parentViewHolder;    if (view == null) {      view = View.inflate(viewGroup.getContext(), R.layout.item_cart_parent, null);      parentViewHolder = new ParentViewHolder(view);      view.setTag(parentViewHolder);    } else {      parentViewHolder = (ParentViewHolder) view.getTag();    }    parentViewHolder.seller_name_tv.setText(dataBean.getSellerName());    boolean currentSellerAllProductSelected = isCurrentSellerAllProductSelected(i);    parentViewHolder.seller_cb.setChecked(currentSellerAllProductSelected);    //D.设置点击CheckBox    parentViewHolder.seller_cb.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        if (mOnCartListChangeListener !=null){          mOnCartListChangeListener.onSellerCheckedChange(i);        }      }    });    return view;  }  @Override  public View getChildView(final int i, final int i1, boolean b, View view, ViewGroup viewGroup) {    CartInfo.DataBean dataBean = list.get(i);    List<CartInfo.DataBean.ListBean> list1 = dataBean.getList();    CartInfo.DataBean.ListBean listBean = list1.get(i1);    ChildViewHolder childViewHolder;    if (view == null) {      view = View.inflate(viewGroup.getContext(), R.layout.item_cart_child, null);      childViewHolder = new ChildViewHolder(view);      view.setTag(childViewHolder);    } else {      childViewHolder=(ChildViewHolder)view.getTag();    }    //设置商品名字    childViewHolder.product_title_name_tv.setText(listBean.getTitle());    //设置商品单价    childViewHolder.product_price_tv.setText(listBean.getPrice()+"");    //设置复选框是否选中    childViewHolder.child_cb.setChecked(listBean.getSelected() == 1);    //设置组合式自定义控件内部的数量    childViewHolder.add_remove_view.setNumber(listBean.getNum());    //D.设置商品CheckBox的点击事件,通过接口回调,暴露给外面    childViewHolder.child_cb.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        if (mOnCartListChangeListener != null){          mOnCartListChangeListener.onProductCheckedChange(i,i1);        }      }    });    //D.设置商品数量的点击事件,通过接口回调,暴露给外面    childViewHolder.add_remove_view.setOnNumberChangeListener(new AddSubView.OnNumberChangeListener() {      @Override      public void onNumberChange(int num) {        if (mOnCartListChangeListener !=null){          mOnCartListChangeListener.onProducNumberChange(i,i1,num);        }      }    });    return view;  }  public boolean isCurrentSellerAllProductSelected(int i){//根据商品改变商家--如果商品全部选中商家则选中--有一个商品没选中则商家不选中    CartInfo.DataBean dataBean = list.get(i);    List<CartInfo.DataBean.ListBean> beans = dataBean.getList();    for (CartInfo.DataBean.ListBean bean : beans){      if (bean.getSelected()==0){        return false;      }    }        return true;  }  public boolean isAllProductsSelected(){ //根据商品改变全选--如果商品全部选中全选则选中--有一个商品没选中则全选不选中    for (int x=0;x<list.size();x++){      CartInfo.DataBean dataBean = list.get(x);      List<CartInfo.DataBean.ListBean> list1 = dataBean.getList();      for (int j=0;j<list1.size();j++){        if (list1.get(j).getSelected()==0){          return false;        }      }    }    return true;  }  public int calculateTotalNumber(){ //计算总数量    int totalNumber=0;    for (int i=0;i<list.size();i++){      CartInfo.DataBean dataBean = list.get(i);      List<CartInfo.DataBean.ListBean> list1 = dataBean.getList();      for (int j=0;j<list1.size();j++){        if (list1.get(j).getSelected()==1){          int num = list1.get(j).getNum();          totalNumber+=num;        }      }    }    return totalNumber;  }  public float calculateTotalPrice(){ //获取总价    float totalPrice=0;    for (int i=0;i<list.size();i++){      CartInfo.DataBean dataBean = list.get(i);      List<CartInfo.DataBean.ListBean> list = dataBean.getList();      for (int j=0;j<list.size();j++){        if (list.get(j).getSelected()==1){          float price = list.get(j).getPrice();          int num = list.get(j).getNum();          totalPrice+=price*num;        }      }    }    return totalPrice;  }  //C.当商品组的全选框点击时,更新所有商品的状态  public void changeCurrentSellerAllProductsStatus(int i,boolean isSelected){    CartInfo.DataBean dataBean = list.get(i);    List<CartInfo.DataBean.ListBean> beans = dataBean.getList();    for (int j=0;j<beans.size();j++){      CartInfo.DataBean.ListBean bean = beans.get(j);      bean.setSelected(isSelected ?1 :0);    }  }  //C.当商家子条目的全选框选中时,更新其状态  public void changeCurrentProductStatus(int i , int i1){    CartInfo.DataBean dataBean = list.get(i);    List<CartInfo.DataBean.ListBean> list = dataBean.getList();    CartInfo.DataBean.ListBean listBean = list.get(i1);    listBean.setSelected(listBean.getSelected() == 0 ? 1 : 0 );  }  //C.设置所有商品的状态  public void changeAllProductStatus(boolean selected){    for(int x=0; x<list.size() ; x++){      CartInfo.DataBean dataBean = list.get(x);      List<CartInfo.DataBean.ListBean> list = dataBean.getList();      for(int j=0; j<list.size(); j++){        list.get(j).setSelected(selected ? 1 : 0);      }    }  }  //C.当加减器被点击时,调用,改变里面当前商品的数量 参数1定位那个商家  参数2定位哪个商品 参数3定位改变具体的数量是多少  public void changeCurrentProductNumber(int i,int i1,int number){    CartInfo.DataBean dataBean = list.get(i);    List<CartInfo.DataBean.ListBean> list = dataBean.getList();    CartInfo.DataBean.ListBean listBean = list.get(i1);    listBean.setNum(number);  }  public interface onCartListChangeListener{    /**     * 当商家的checkBox点击时回调     */    void onSellerCheckedChange(int i);    /**     * 当点击子条目商品的CheckBox回调     */    void onProductCheckedChange(int i ,int i1);    /**     * 当点击加减按钮的回调     */    void onProducNumberChange(int i , int i1 , int number);  }  //D.  onCartListChangeListener mOnCartListChangeListener;  //D.  public void setOnCartListChangeListener(onCartListChangeListener onCartListChangeListener){    mOnCartListChangeListener = onCartListChangeListener ;  }  public static class ParentViewHolder {    public CheckBox seller_cb;    public TextView seller_name_tv;    public ParentViewHolder(View rootView) {      this.seller_cb = (CheckBox) rootView.findViewById(R.id.seller_cb);      this.seller_name_tv = (TextView) rootView.findViewById(R.id.seller_name_tv);    }  }  public static class ChildViewHolder {    public CheckBox child_cb;    public ImageView product_icon_iv;    public TextView product_title_name_tv;    public TextView product_price_tv;    public AddSubView add_remove_view;    public ChildViewHolder(View rootView) {      this.child_cb = (CheckBox) rootView.findViewById(R.id.child_cb);      this.product_icon_iv = (ImageView) rootView.findViewById(R.id.product_icon_iv);      this.product_title_name_tv = (TextView) rootView.findViewById(R.id.product_title_name_tv);      this.product_price_tv = (TextView) rootView.findViewById(R.id.product_price_tv);      this.add_remove_view = (AddSubView) rootView.findViewById(R.id.add_remove_view);    }  }  @Override  public Object getGroup(int i) {    return null;  }  @Override  public Object getChild(int i, int i1) {    return null;  }  @Override  public long getGroupId(int i) {    return 0;  }  @Override  public long getChildId(int i, int i1) {    return 0;  }  @Override  public boolean hasStableIds() {    return false;  }  @Override  public boolean isChildSelectable(int i, int i1) {    return false;  }}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent">  <ExpandableListView    android:id="@+id/el_cart"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:layout_marginBottom="60dp" />  <LinearLayout    android:layout_width="match_parent"    android:layout_height="60dp"    android:layout_alignParentBottom="true"    android:background="#eeeeee"    android:gravity="center_vertical">    <CheckBox      android:id="@+id/cb_cart_all_select"      android:layout_width="wrap_content"      android:layout_height="wrap_content" />    <TextView      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="全选" />    <TextView      android:id="@+id/tv_cart_total_price"      android:layout_width="0dp"      android:layout_height="wrap_content"      android:layout_weight="1"      android:paddingLeft="20dp"      android:text="合计:¥0.00" />    <Button      android:id="@+id/btn_cart_pay"      android:layout_width="100dp"      android:layout_height="match_parent"      android:text="去结算(0)" />  </LinearLayout></RelativeLayout>

public class AddSubView extends LinearLayout implements View.OnClickListener{  //组合式控件  private int number = 1;  private TextView sub_tv;  private TextView product_number_tv;  private TextView add_tv;  public AddSubView(Context context) {    this(context,null);  }  public AddSubView(Context context, @Nullable AttributeSet attrs) {    this(context, attrs,0);  }  public AddSubView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {    super(context, attrs, defStyleAttr);    View view = inflate(context, R.layout.add_remove, this);    sub_tv=view.findViewById(R.id.sub_tv);    product_number_tv=view.findViewById(R.id.product_number_tv);    add_tv=view.findViewById(R.id.add_tv);    sub_tv.setOnClickListener(this);    add_tv.setOnClickListener(this);  }  @Override  public void onClick(View view) {    switch (view.getId()){      case R.id.sub_tv:        if (number>1){          --number;          product_number_tv.setText(number+"");          if (onNumberChangeListener!=null){            onNumberChangeListener.onNumberChange(number);          }        }else {          Toast.makeText(getContext(), "不能再少了", Toast.LENGTH_SHORT).show();        }        break;      case R.id.add_tv:        if (number<8){          ++number;          product_number_tv.setText(number+"");          if (onNumberChangeListener!=null){            onNumberChangeListener.onNumberChange(number);          }        }else {          Toast.makeText(getContext(), "不能再多了", Toast.LENGTH_SHORT).show();        }        break;    }  }  public int getNumber() {    return number;  }  public void setNumber(int number) {    this.number = number;    product_number_tv.setText(number + "");  }  OnNumberChangeListener onNumberChangeListener;  public void setOnNumberChangeListener(OnNumberChangeListener onNumberChangeListener) {    this.onNumberChangeListener = onNumberChangeListener;  }  interface OnNumberChangeListener {    void onNumberChange(int num);  }}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:padding="2dp"  android:layout_marginLeft="10dp"  android:layout_width="60dp"  android:layout_height="30dp"  android:layout_gravity="center_vertical"  android:background="#99000000"  android:gravity="center_vertical">  <TextView    android:background="#ffffff"    android:layout_weight="1"    android:id="@+id/sub_tv"    android:layout_width="0dp"    android:layout_height="match_parent"    android:gravity="center"    android:text="-"    android:textSize="16sp" />  <TextView    android:text="1"    android:layout_marginLeft="2dp"    android:background="#ffffff"    android:layout_weight="1"    android:id="@+id/product_number_tv"    android:layout_width="0dp"    android:layout_height="match_parent"    android:gravity="center"    />  <TextView    android:layout_marginLeft="2dp"    android:background="#ffffff"    android:layout_weight="1"    android:id="@+id/add_tv"    android:layout_width="0dp"    android:layout_height="match_parent"    android:gravity="center"    android:text="+"    android:textSize="16sp" /></LinearLayout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"   //商家条目  android:layout_width="match_parent"  android:layout_height="60dp"  android:gravity="center_vertical"  >  <CheckBox    android:id="@+id/seller_cb"    android:layout_width="wrap_content"    android:layout_height="wrap_content" />  <TextView    android:id="@+id/seller_name_tv"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_marginLeft="20dp" /></LinearLayout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="120dp"  android:gravity="center_vertical">  <CheckBox    android:id="@+id/child_cb"    android:layout_width="wrap_content"    android:layout_height="wrap_content" />  <ImageView    android:id="@+id/product_icon_iv"    android:layout_width="80dp"    android:layout_height="80dp"    android:layout_marginLeft="20dp"    android:scaleType="centerCrop"    android:src="@color/colorPrimary" />  <LinearLayout    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_weight="1"    android:orientation="vertical">    <TextView      android:id="@+id/product_title_name_tv"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:ellipsize="end"      android:maxLines="2"      android:text="商品标题" />    <TextView      android:id="@+id/product_price_tv"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:layout_marginTop="10dp"      android:text="¥0.0" />  </LinearLayout>  <fanruiqi.bwie.com.shopcat.AddSubView    android:id="@+id/add_remove_view"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_marginRight="10dp" /></LinearLayout>

public class OkhtttpUtils {  private static OkhtttpUtils mOkhtttpUtils;  private OkHttpClient mOkHttpClien;  private final Handler mHandler;  private OkhtttpUtils() {    //创建一个主线程的handler    mHandler = new Handler(Looper.getMainLooper());    mOkHttpClien = new OkHttpClient.Builder()        .connectTimeout(5000, TimeUnit.MILLISECONDS)        .readTimeout(5000, TimeUnit.MILLISECONDS)        .writeTimeout(5000, TimeUnit.MILLISECONDS)        .build();  }  //单例模式  public static OkhtttpUtils getInstance() {    if (mOkhtttpUtils == null) {      synchronized (OkhtttpUtils.class) {        if (mOkhtttpUtils == null) {          return mOkhtttpUtils = new OkhtttpUtils();        }      }    }    return mOkhtttpUtils;  }  public interface OkCallback {    void onFailure(Exception e);    void onResponse(String json);  }  public void doPost(String url, Map<String, String> map, final OkCallback okCallback) {    //创建FormBody的对象,把表单添加到formBody中    FormBody.Builder builder = new FormBody.Builder();    if (map != null) {      for (String key : map.keySet()) {        builder.add(key, map.get(key));      }    }    FormBody formBody = builder.build();    //创建Request对象    Request request = new Request.Builder()        .post(formBody)        .url(url)        .build();    //创建Call对象    final Call call = mOkHttpClien.newCall(request);    call.enqueue(new Callback() {      @Override      public void onFailure(Call call, final IOException e) {        if (okCallback != null) {          //切换到主线程          mHandler.post(new Runnable() {            @Override            public void run() {              okCallback.onFailure(e);            }          });        }      }      @Override      public void onResponse(Call call, final Response response) throws IOException {        try {          if (response != null && response.isSuccessful()) {            final String json = response.body().string();            mHandler.post(new Runnable() {              @Override              public void run() {                if (okCallback != null) {                  okCallback.onResponse(json);                  return;                }              }            });          }        } catch (IOException e) {          e.printStackTrace();        }        if (okCallback != null) {          okCallback.onFailure(new Exception("网络异常"));        }      }    });  }  //封装doGet的网络请求  public void doGet(String url, final OkCallback okCallback) {    Request request = new Request.Builder()        .get()        .url(url)        .build();    final Call call = mOkHttpClien.newCall(request);    call.enqueue(new Callback() {      @Override      public void onFailure(Call call, final IOException e) {        if (okCallback != null) {          //切换到主线程          mHandler.post(new Runnable() {            @Override            public void run() {              okCallback.onFailure(e);            }          });        }      }      @Override      public void onResponse(Call call, final Response response) throws IOException {        try {          if (response != null && response.isSuccessful()) {            final String json = response.body().string();            mHandler.post(new Runnable() {              @Override              public void run() {                if (okCallback != null) {                  okCallback.onResponse(json);                  return;                }              }            });          }        } catch (IOException e) {          e.printStackTrace();        }      }    });  }}