React-Native使用Mobx实现购物车功能

在工作中，购物车场景非常常见。本文实现基于React-Native和Mobx实现两种购物车例子。

其中，后期会加入动画等其他。本期先实现基础功能。

二：基于State实现购物车

1-：ShoppingCarPage.js

export default class ShoppingCarPage extends Component {
  static navigationOptions = {
    headerTitle : '基于State购物车',
  };

  constructor(props) {
    super(props);
    this.state = {
      allSelecte : data.isAllSelect,
      totalMoney : data.totalMoney,
    }

  };

  getMoney = (m) => {
    this.state.totalMoney=this.state.totalMoney+m;
    //this.state.totalMoney += m;
    data.totalMoney = this.state.totalMoney;
    this.setState({
      totalMoney : this.state.totalMoney
    });

    let i = 0;
    data.datas.map((item) => {
      if (item.isSelect != true) {
 i += 1;
      }
    });
    if (i == 0) {
      data.isAllSelect = true;
      this.setState({ allSelecte : true })
    }
    else {
      data.isAllSelect = false;
      this.setState({ allSelecte : false })
    }
  };

  renderItem = (item) => {
    return (
      
    )
  };

  allSelect = () => {
    data.totalMoney = 0;
    data.isAllSelect = !data.isAllSelect;
    this.state.totalMoney = 0;
    DeviceEventEmitter.emit('allSelect', !this.state.allSelecte);
    this.setState({ allSelecte : !this.state.allSelecte })
  };

  separatorView = () => {
    return (
      
    )
  };

  keyExtractor = (item) => item.name;

  render() {
    let { allSelecte, totalMoney } = this.state;
    return (
      
  this.renderItem(item)}
      keyExtractor={ this.keyExtractor }
 />
 
   
     

全选
     
     
￥{this.state.totalMoney}
     
   
   
     去结算
   
 


      
    );
  }
}

2-：ShoppingItemComponent.js

export default class ShoppingItemComponent extends Component {

  static propTypes = {
    itemdata: PropTypes.object.isRequired,
    money : PropTypes.func,
  };

  static defaultProps = {
    money : () => null,
  };

  componentDidMount() {
    this.subscription = DeviceEventEmitter.addListener('allSelect', (isSelAll) => {
      this.props.itemData.isSelect = isSelAll;
      this.setState({ isSel : isSelAll });
      if (isSelAll) {
 this.setMoney(this.state.money * this.state.selNum);
      }

    })
  };

  componentWillUnmount() {
    this.subscription && this.subscription.remove();
  };

  constructor(props) {
    super(props);
    this.state = {
      isSel : this.props.itemData.isSelect,
      selNum : this.props.itemData.count,
      money : this.props.itemData.money,
      name : this.props.itemData.name,
      description : this.props.itemData.description,
      img : this.props.itemData.img,
    }
  };

  itemSelect = (item) => {
    this.setState({isSel :!this.state.isSel},()=>{
      if (this.state.isSel) {
 this.setMoney(this.state.money * this.state.selNum)
      }
      else {
 this.setMoney(-this.state.money * this.state.selNum)
      }
    });
  };

  itemIncrease = (i) => {
    i++;
    this.setState({selNum : i},()=>{
      if (this.state.isSel) {
 this.setMoney(this.state.money)
      }else{
 this.setState({isSel :true});
 this.setMoney(this.state.money * this.state.selNum);
      }
      this.props.itemData.count = i;
    });
  };

  itemReduce = (i) => {
    if (i <= 1) {
      if(this.state.isSel){
 this.setState({isSel :!this.state.isSel});
 this.setMoney(-this.state.money)
      }
      return;
    }
    i--;
    this.setState({ selNum : i },()=>{
      if (this.state.isSel) {
 this.setMoney(-this.state.money)
      }else{
 this.setState({isSel :true});
 this.setMoney(this.state.money * this.state.selNum);
      }
      this.props.itemData.count = i;
    });

  };

  setMoney = (money) => {
    if (this.props.money) {
      this.props.money(money);
    }
  };

  render() {
    let { itemData } = this.props;
    let { isSel, selNum, money, name, description, img } = this.state;
    return (
      
  this.itemSelect(itemData)}>
   
 
 
 
   { name }
   { description }
   
     < Text style={ styles.moneyStyle }>￥{ money }
     

 this.itemReduce(selNum)}>
  -


  { selNum }

 this.itemIncrease(selNum)}>
  +

     
   
 
      
    );
  }
}

三：基于Mobx实现购物车

1-：MobxShoppingCarPage.js

@observer
export default class MobxShoppingCarPage extends Component {
  static navigationOptions = {
    headerTitle : '基于MobX购物车',
  };

  constructor(props) {
    super(props);
    this.data = new MobxStore();
  };

  componentDidMount() {
    this.data.replace(jsonData)
  };

  @action
  allSelect = () => {
    DeviceEventEmitter.emit('allSelect', !this.data.itemData.isAllSelect);
    this.data.selectAll();
  };

  renderItem = (item) => {
    return (
      
    )
  };

  separatorView = () => {
    return (
      
    )
  };

  keyExtractor = (item) => item.name;

  render() {
    return (
      
  this.renderItem(item) }
      keyExtractor={ this.keyExtractor }
 />
 
   
     

全选
     
     
￥{ this.data.itemData.totalMoney }
     
   
   
     去结算
   
 
      
    );
  }
}

2-：MobxShopItemComponent.js

@observer
export default class MobxShopItemComponent extends Component {

  static propTypes = {
    itemdata: PropTypes.object.isRequired,
    data: PropTypes.object.isRequired,
  };

  constructor(props) {
    super(props);
    this.itemData = this.props.itemData;
  }

  componentDidMount() {
    this.subscription = DeviceEventEmitter.addListener('allSelect', (isSelAll) => {
      this.itemData.isSelect = isSelAll;
    })
  };

  componentWillUnmount() {
    this.subscription && this.subscription.remove();
  };

  @action
  selectPress = () => {
    this.itemData.isSelect = !this.itemData.isSelect;
    let money = this.itemData.money * this.itemData.count;
    if (this.itemData.isSelect) {
      this.props.data.increase(money);
    }
    else {
      this.props.data.reduce(money)
    }
    this.props.data.itemPress();
  };

  @action
  increase = () => {
    this.itemData.count += 1;
    if (this.itemData.isSelect) {
      this.props.data.increase(this.itemData.money);
    }else{
      this.itemData.isSelect = !this.itemData.isSelect;
      this.props.data.increase(this.itemData.money * this.itemData.count);
    }

  };

  @action
  reduce = () => {
    if (this.itemData.count <= 1) {
      if(this.itemData.isSelect){
 this.itemData.isSelect = !this.itemData.isSelect;
 this.props.data.reduce(this.itemData.money);
      }
      return;
    }
    this.itemData.count -= 1;
    if (this.itemData.isSelect) {
      this.props.data.reduce(this.itemData.money);
    }
  };

  render() {
    return (
      
 
   
 
 
 
   { this.itemData.name }
    { this.itemData.description }
   
     < Text style={ styles.moneyStyle }>￥{ this.itemData.money }
     

  -


  { this.itemData.count }


  +

     
   
 
      
    );
  }
};

3-：MobxStore.js

import { observable, action, computed, autorun } from 'mobx';

export default class MobxStore {
  @observable
  itemData = {}

  //设置数据
  replace = (data) => {
    this.itemData = data;
  }

  //按下的反选
  itemPress = () => {
    let i = 0;
    this.itemData.datas.map((item) => {
      if (item.isSelect != true) {
 i += 1;
      }
    });
    if (i == 0) {
      this.itemData.isAllSelect = true;
    }
    else {
      this.itemData.isAllSelect = false;
    }
  }

  //加
  increase = (money) => {
    this.itemData.totalMoney += money;
  }

  //减
  reduce = (money) => {
    this.itemData.totalMoney -= money;
  }

  //全选
  selectAll = () => {
    this.itemData.isAllSelect = !this.itemData.isAllSelect;
    this.itemData.totalMoney = 0;
    if (this.itemData.isAllSelect) {
      for (let i = 0;
 i < this.itemData.datas.length;
 i++) {
 this.itemData.totalMoney += this.itemData.datas[ i ].money * this.itemData.datas[ i ].count;
      }
    }
  }
}

四：

1-：代码github地址：https://github.com/erhutime/React-Navigation-All/tree/master/All/jscode/shoppingcar/src

2-：下载完成后，修改index.ios.js:入口文件如下：

运行效果如下：

import App from './jscode/shoppingcar/src/App'
AppRegistry.registerComponent('All', () => App);

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。