今天记录一下购物车案例，实现购物车的全选，单选，数量加一减一，金额总数，以及清空购物车。

     
          
              
                   
                    
                         
                         
                         
         
          
                         
         
          {
   {item.title}}
                         
         
          ￥{
   {item.price}}
                         
                             
          
           -
                              
          
           { {item.num}}
                              
          
           +
                          
                         
         
          ×
                     
                
               
               
                    
                    
                    
        
         
                    
        
         全选
                    
                    
        
         ￥{
   {totalPrice}}
                
           
          
              
       
        购物车是空的哦~
           
      
     

// page/component/new-pages/cart/cart.jsPage({  data: {    carts:[],               // 购物车列表    hasList:false,          // 列表是否有数据    totalPrice:0,           // 总价，初始为0    selectAllStatus:true    // 全选状态，默认全选  },  onShow() {    this.setData({      hasList: true,      carts:[        {id:1,title:'白菜 半斤',image:'/image/s5.png',num:4,price:0.02,selected:true},        {id:2,title:'素米 500g',image:'/image/s6.png',num:1,price:0.05,selected:true}      ]    });    this.getTotalPrice();  },  /**   * 当前商品选中事件   */  selectList(e) {    const index = e.currentTarget.dataset.index;    let carts = this.data.carts;    const selected = carts[index].selected;    carts[index].selected = !selected;    this.setData({      carts: carts    });    this.getTotalPrice();  },  /**   * 删除购物车当前商品   */  deleteList(e) {    const index = e.currentTarget.dataset.index;    let carts = this.data.carts;    carts.splice(index,1);    this.setData({      carts: carts    });    if(!carts.length){      this.setData({        hasList: false      });    }else{      this.getTotalPrice();    }  },  /**   * 购物车全选事件   */  selectAll(e) {    let selectAllStatus = this.data.selectAllStatus;    selectAllStatus = !selectAllStatus;    let carts = this.data.carts;    for (let i = 0; i < carts.length; i++) {      carts[i].selected = selectAllStatus;    }    this.setData({      selectAllStatus: selectAllStatus,      carts: carts    });    this.getTotalPrice();  },  /**   * 绑定加数量事件   */  addCount(e) {    const index = e.currentTarget.dataset.index;    let carts = this.data.carts;    let num = carts[index].num;    num = num + 1;    carts[index].num = num;    this.setData({      carts: carts    });    this.getTotalPrice();  },  /**   * 绑定减数量事件   */  minusCount(e) {    const index = e.currentTarget.dataset.index;    let carts = this.data.carts;    let num = carts[index].num;    if(num <= 1){      return false;    }    num = num - 1;    carts[index].num = num;    this.setData({      carts: carts    });    this.getTotalPrice();  },  /**   * 计算总价   */  getTotalPrice() {    let carts = this.data.carts;                  // 获取购物车列表    let total = 0;    for(let i = 0; i