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项目管理
HarmonyOS
问题
- 如何计算被选中商品的总价，当商品数量发生改变
情景：当超过一个以上的商品被选中时可以监听到所有选中商品的价格，但是如果修改其中一个商品数量时，只监听到了被修改商品的信息。图片描述
修改数量前勾选都可以监听到
只监听到修改的
我需要当check box 状态改变时，total 数量发生相应变换。如果一个选中的产品数量变化时total也发生相应改变
结构
ShopCart > CartRow
代码
parent component: ShopCart
class ShopCart extends Component{
constructor(...args){
super(...args);
var that = this;
this.state={
isChecked: false,
checkedCount: 0,
total: 0
};
this.item = Constant.productCart;
this.number = 0;
this.countChecked = (isChecked) => {
this.setState({isChecked: isChecked});
isChecked ?
this.setState({checkedCount: this.state.checkedCount + 1})
:
this.setState({checkedCount: this.state.checkedCount - 1})
}
this.totalCheckedPrice = (isChecked, totalPrice) => {
if(isChecked) {
console.log(totalPrice);
}
}
}
componentWillMount() {
}
componentDidMount(){
}
render(){
return(
<form className="shopCart contain">
<Table condensed hover>
<thead>
<tr>
<th className="hiddenColumn">
<label>
<input type="checkbox" className="check-all check"/>
</label>
</th>
<th colSpan="2">Product</th>
<th>Price</th>
<th>Quantity</th>
<th>Total</th>
<th>Remove</th>
</tr>
</thead>
<tbody>
{
this.item.length > 0 &&
this.item.map((item, index) => {
return(
<CartRow key={index}
rowItem={item}
countChecked = {this.countChecked}
totalCheckedPrice = {this.totalCheckedPrice}
/>
)
})
}
</tbody>
<tfoot>
<tr>
<th></th>
<th></th>
<th>
<span className="orangeButton">
Empty Cart
</span>
</th>
<th colSpan="2">
Selected
<span className="orangeText">
{this.state.checkedCount}
</span>
Items
</th>
<th>Total:
<span className="orangeText">
{this.state.total}
</span>
</th>
<th className="checkout">
<span>
Checkout
</span>
</th>
</tr>
</tfoot>
</Table>
</form >
)
}
}child component: CartRow
class CartRow extends Component{
constructor(...args){
super(...args);
var that = this;
this.state={
isChecked: false,
count: 1,
};
//input(text) value changed control
this.handleChange = (event) => {
this.setState({count: event.target.value });
}
this.increment = () => {
this.setState({count: this.state.count + 1});
}
this.decrement = () => {
if(this.state.count > 1) {
this.setState({count: this.state.count - 1});
}
}
//input checkbox value changed control
this.onChangedAction = (event) => {
this.setState({isChecked: event.target.checked})
event.target.checked ?
this.props.countChecked(true)
:
this.props.countChecked(false)
}
//subTotal price when input(text) value changed
this.subTotal = () => {
this.props.totalCheckedPrice(this.state.isChecked, Math.abs(this.state.count * this.props.rowItem.price))
return Math.abs(this.state.count * this.props.rowItem.price);
}
}
componentWillMount() {
}
componentDidMount(){
}
render(){
return(
<tr>
<td className="hiddenColumn">
<input type="checkbox"
checked={this.state.isChecked}
onChange={this.onChangedAction.bind(this)}/>
</td>
<td className="hiddenColumn">
<img src={this.props.rowItem.image} alt=""/>
</td>
<td data-column="Product">
{this.props.rowItem.title}
</td>
<td data-column="Price">
{this.props.rowItem.price}
</td>
<td className="count" data-column="Quality">
<span className='fa-stack reduce'
onClick={this.decrement.bind(this)}>
<Fontawesome name="minus" stack='1x'></Fontawesome>
</span>
<input type="text" className="count-input"
onChange={this.handleChange.bind(this)}
value={this.state.count}/>
<span className='fa-stack add'
onClick={this.increment.bind(this)}>
<Fontawesome name="plus" stack='1x'></Fontawesome>
</span>
</td>
<td className="subTotal" data-column="SubTotal">
{
this.subTotal()
}
</td>
<td data-column="Remover">
<span className='fa-stack'>
<Fontawesome name="trash-o" stack='1x'></Fontawesome>
</span>
</td>
</tr>
)
}
}数据结构
exports.productCart= [
{
title: 'Hello my demo2',
image: 'https://pbs.twimg.com/media/CwGgapPVUAA4u3Q.jpg',
price: 76
},
{
title: 'Hello my demo2',
image: 'http://i.imgur.com/RRUe0Mo.png',
price: 676
},
{
title: 'Pasifika Early Childhood CD (with printed lyrics)',
image: 'https://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2014/4/11/1397210130748/Spring-Lamb.-Image-shot-2-011.jpg',
price: 234
},
{
title: 'Hello my demo2',
image: 'http://mblogthumb1.phinf.naver.net/20121009_136/dogtalk__1349752474508pRuyE_JPEG/Puppy-Love-29817_large.jpg?type=w2',
price: 788
},
{
title: 'Hello my demo2',
image: 'https://www.codeproject.com/KB/GDI-plus/ImageProcessing2/flip.jpg',
price: 96
},
{
title: 'Hello my demo2',
image: 'https://amazingslider.com/wp-content/uploads/2012/12/dandelion.jpg',
price: 67
},
];
代码有点多，大概看了一下，说一下我的思路吧。
首先的你数据结构，每一项至少应该有商品的id吧，再加上一个是否选中和当前数量
父组件维护两个state，一个是包含被勾选商品的数组，另一个是总价（总价遍历数组算出来就可以了）
对于子组件来说有两个动作，勾选和改变数量，无论哪个动作发生都把当前这条数据传给父组件
父组件拿到数据后遍历被勾选商品的数组，对比id
1.如果没有找到相同id,再看是否选中，没有选中不做操作，选中了就加到数组里
2.有相同id,看是否选中，没有选中就把这条从数组里去除，选中了的就更新商品数量
就是这样~ 若可行望采纳