如何使用ethersjs和metamask与angular服务签署sendTransaction

Question

我正在使用angular 9，当我尝试运行以下代码时，我得到了以下错误。如何签署交易？

错误：发送交易需要签名人(操作="sendTransaction"，版本=4.0.47(

onSubmit(form: NgForm) {
console.log(form);
this.submitted = true;
// TODO: This is where we connect to the solidity contract to create client.
this.clientService.createClient(form.controls['accountAddress'].value, form.controls['name'].value).subscribe(
(model: Client) =>
{
this.model = model;
console.log('MODEL='+model);
}, error => {
console.log("error"+error);
});
}

export class ClientServiceService {
//mweb3 = new Web3(new Web3.providers.HttpProvider('http://localhost:7545')); // keeping this for future reference.
// Attempting to use the example from MI4-exercise7 to use metamask
provider = new ethers.providers.EtherscanProvider('ropsten')
contractAddress = "0xe6482f6554074c666593b5f38fe5357828a1fbd7";
contractABI = [...];
contract = new ethers.Contract(this.contractAddress, this.contractABI, this.provider);
//constructor(private http: HttpClient) { }
constructor() { }
// getInvoiceTracker(): ethers.Contract {
//   return this.contract.new();
// }
createClient(clientID: string, clientName: string): Observable<any> {
return from(this.contract.addClient(clientID, clientName));
}
}

Answer 1

要发送事务，需要使用带有签名者的提供程序。

const wallet = new ethers.Wallet(privateKey, provider)

然后将您的合同实例连接到签名者。

contract.connect(wallet)

如果您正在连接MetaMask，则从窗口web3提供程序创建一个ethers提供程序：

provider = new ethers.providers.Web3Provider(window.ethereum)