方法在前面的方法完成之前运行，未来异步Dart

Question

我的方法processData()是在pullAllData()完成之前执行的，但是我需要processData()在运行之前等待pullAllData()完全完成。当运行isDownloadSuccessful ()时，这将导致我的processData bool为空。

Future getCoinData() async {
    calculateNumberOfDataPoints();
    pullTimesAndPrices();
    return timesAndPrices;
  }

Future pullTimesAndPrices() async {
    for (String cryptoCurrency in cryptoAbbreviation) {
      pullAllData(cryptoCurrency);
      processData(cryptoCurrency);
    }
  }

Future pullAllData(cryptoCurrency) async {
    String historicalRequestURL =
        '$cryptoAPIURL$cryptoCurrency$currency/ohlc?periods=$periodValue&apikey=$apiKey';
    http.Response historicalResponse = await http.get(historicalRequestURL);
    isPullSuccessful = (historicalResponse.statusCode == 200);
  }

void processData(cryptoCurrency) {
    if (isPullSuccessful) {
      ...
    } else {
      throw 'Problem pulling data';
    }
  }

Answer 1

您正在将函数pullTimesAndPrices标记为async，但不使用await。在调用await函数之前使用pullAllData关键字。