'getPastEvents'没有响应

Question

interactions.js

export const loadAllOrders = async (exchange, dispatch) => {
  // Fetch cancelled orders with the "Cancel" event stream
  const cancelStream = await exchange.getPastEvents('Cancel', { fromBlock: 0, toBlock: 'latest' })
  console.log(cancelStream)
}

但是这样的错误

我不知道问题是什么

如果您知道，请帮助

对不起，加上Content.js

import React, { Component } from 'react'
import { connect } from 'react-redux'
import { exchangeSelector } from '../store/selectors'
import { loadAllOrders } from '../store/interactions'

class Content extends Component {
  componentWillMount() {
    this.loadBlockchainData(this.props.dispatch)
  }

  async loadBlockchainData(dispatch) {
    await loadAllOrders(this.props.exchange, dispatch)
  }
 ~~~

function mapStateToProps(state) {
  return {
    exchange: state.exchangeSelector
  }
}

export default connect(mapStateToProps)(Content)

加上新代码

Answer 1

无法读取未定义的属性“ getPastEvents”。这意味着当您调用函数x时exchange是undefined。

loadAllOrders

因此，您必须像这样将参数传递到async loadBlockchainData(dispatch) { await loadAllOrders(this.props.exchange, dispatch) // You can not direct access to this.props with function in Class // this.props just direct shaft access only in life cycle and render } 中：

loadBlockchainData

在渲染器中调用此函数：

async loadBlockchainData(exchange, dispatch) {
    await loadAllOrders(exchange, dispatch)
}

Answer 2

可能你已经解决了或者放弃了，;) 但是对于未来的读者，请检查您的选择器文件并确保您的 exchangeSelector 如下所示：

const exchange = state => get(state, 'exchange.contract')
export const exchangeSelector = createSelector(exchange, e => e)

我忘了把 get，它确实在 undefined 中解决了交换....