javascript - 单击链接时删除子组件

Question

我现在正在教自己使用react，我有一个查看状态的组件，当添加新项目时，它会将一个子组件附加到自身。我现在想做的是通过单击删除添加的子组件。但是，我似乎无法获得链接停止的自然事件，如果我执行e.preventDefault()，我会得到preventDefault is not a function of undefined。

下面是我的代码，

    import React, { Component } from 'react';
import InvoiceForm from './InvoiceForm';
import InvoiceItemForm from './InvoiceItemForm';

class GenerateInvoice extends Component {

  constructor(props) {
    super(props);
    this.state = {
      invoice: {
        items : []
      }
    };

    this.onAddChild = this.onAddChild.bind(this);
    this.removeItem = this.removeItem.bind(this);
  }

  render() {
    const children = [];
    for (var i = 0; i < this.state.invoice.items.length; i += 1) {
      children.push(
        <InvoiceItemForm 
          key={i} 
          number={i}
          remove={this.removeItem} />
      );
    }
    return(
      <div>
        <a href="" onClick={this.onAddChild}>Add New Item</a>
        {children}
      </div>
    )
  }

  removeItem = (e, itemIndex) => {
    e.stopPropagation();
    alert("..removing...");
    // let invoice = this.state.invoice;
    // let updatedItems = this.state.invoice.items.splice(index, 1); //remove element
    // let updateInvoice = { ...invoice, items:updatedItems}
    // this.setState({ invoice }); //update state
  }

  onAddChild = (e) => {
    e.preventDefault();
    let invoice = this.state.invoice;
    // creates an updated version of the items without changing the original value
    let updatedItems = invoice.items.push({ 'id': 'INV001' });
    // creates a new version of the invoice with the updated items
    let updateInvoice = { ...invoice, items: updatedItems };
    // update the invoice on the state to the new version
    this.setState({ invoice });
  }


}

导出默认GenerateInvoice；

子组件

    import React from 'react';

const InvoiceItemForm = (props) => {
  console.log(props);
  return(
    <div>
      <p>Hello {props.number}</p>
      <a href="" onClick={props.remove(props.number)}>Remove</a>
    </div>
  )
}

export default InvoiceItemForm;

以及我的沙箱的链接，

https://codesandbox.io/s/0qx9w1qrwv

Answer 1

在 InvoiceItemForm 组件上，onClick={props.remove(props.number)}，只有在这里您才可以引用事件对象。

您可以更改为:

onClick={(e) => {
  e.preventDefault();
  props.remove(props.number);
}}

编辑:

如果您想避免每次渲染都创建一个函数，您可以使用以下内容:

class InvoiceItemForm extends React.Component {
  handleClick = (e) => {
    e.preventDefault();
    this.props.remove(props.number);
  }

  render() {
    console.log(this.props);
    return(
      <div>
        <p>Hello {this.props.number}</p>
        <a href="" onClick={this.handleClick}>Remove</a>
      </div>
    )
  }
}