Question

我想让回调在执行下一行代码之前等待响应。我确实尝试过先进行回调async，然后进行await的响应，但这没用。

async signup(parent, args, ctx, info) {

    const email = args.email;
    let res;
    verifier.verify(email, function(err, response) {
      if (err) console.log(err);
      else {
        res = response.success;
        console.log('before', res); // true or false
      }
    });
    console.log('after', res); // undefined
}

Answer 1

async function signup (parent, args) {
  return new Promise(function(resolve, reject) {
    verifier.verify(args.email, function(err, response) {
      if (err) { 
        reject(err);
      }
      else {
        resolve(response.success);
      }
    });
  });
}

Answer 2

创建一个函数并在获得响应后执行它

async signup(parent, args, ctx, info) {

const email = args.email;
let res;
verifier.verify(email, function(err, response) {
  if (err) console.log(err);
  else {
    res = response.success;
    console.log('before', res); // true or false
    nextfun(res)
  }
});
}


function nextfun(res) {
 console.log(res)
}

Answer 3

 async signup(parent, args, ctx, info) {

    let res = await new Promise(function(resolve, reject) {
      verifier.verify(args.email, function(err, response) {
        if (err) {
          reject(err);
        } else {
          resolve(response.success);
        }
      });
    });

    console.log('after', res); // response.success

}

我想让回调在执行下一行代码之前等待响应

3 个答案: