Question

我试图在智能合约上调用一个函数。这是我的CarService.ts代码：

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import { fromPromise } from 'rxjs/observable/fromPromise';
import { Web3Service } from './web3.service'

declare var require: any;
const carArtifacts = require('../../../build/contracts/Car.json');
const contract = require('truffle-contract');



@Injectable()
export class CarServiceService {


CarContract = contract(carArtifacts);

constructor(private web3ser: Web3Service) {

this.CarContract.setProvider(web3ser.web3.currentProvider)

}



getCarDetail():Observable<any>{
return Observable.create(observer =>{
  this.CarContract
    .deployed()
    .then(instance =>{
      console.log('instaaance', instance)
      return instance.model.call()

  })
    .then(value =>{
    observer.next(value)
    observer.complete()
  })
    .catch(err =>{
    console.log('errrrrrrrrrr', err)
  })
  })
  }

  }

这是我的appComponent.ts代码：

import { Component, HostListener, NgZone } from '@angular/core';
import { canBeNumber } from './util/validation';

import { Web3Service } from './services/web3.service'
import { CarServiceService} from "./services/car-service.service"

@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'app';
accounts: any;
account: any;
carRes: any;

constructor(
private _ngZone: NgZone,
private web3Service: Web3Service,
private carser: CarServiceService
) {
this.onReady();
}


 onReady = () => {

  // Get the initial account balance so it can be displayed.
  this.web3Service.getAccounts().subscribe(accs => {
  this.accounts = accs;
  this.account = this.accounts[0];
  console.log('accccccouuuuntsss', this.accounts)

  this.CarDetail()

  }, err => alert(err))

  }


 CarDetail= ()=>{
  this.carser.getCarDetail()
  .subscribe(val=>{
  this.carRes = val;
  console.log('caaaar moddeeel', this.carRes)
  }, err => alert(err))
  }
 }

我只是不明白为什么我在尝试获取汽车细节时仍然遇到错误：TypeError：无法读取未定义的属性'apply' 在Provider.sendAsync

如果有人能帮助我，我会非常感激，谢谢，

Answer 1

这是web3 @ 1＆amp; amp;的兼容性问题。 truffle-contract@3.0.4。尝试在创建web3实例之前添加此行：

Web3.providers.HttpProvider.prototype.sendAsync = Web3.providers.HttpProvider.prototype.send;

Answer 2

可以this帮助你。看起来你有不兼容的依赖关系vesions

TypeError：无法在Provider.sendAsync中读取未定义的属性“apply”

2 个答案: