dart 中使用 stdin 输出数字的问题

Question

带有数字的输出不起作用，我只能写第一个数字，之后应用程序将关闭。

void main(List<String> args) {
  print("Escreva o numero de carros vendidos pelo funcionario ");
  int nuyCar = stdin.readByteSync().toInt();

  print("Escreva o salario fixo do funcionario: ");
  double fixSalary = stdin.readByteSync().toDouble();

  print("Escreva o valor arrecadado das vendas do funcionario: ");
  double priceCollected = stdin.readByteSync().toDouble();

  print(nuyCar);
  print(fixSalary);
  print(priceCollected);
}

Answer 1

嗯，Dart 是严重依赖空检查的语言之一。在这里阅读更多相关信息 -> https://dart.dev/null-safety

您应该养成检查这些的习惯。此外，您还可以使用 readLineSync()，而不是 readBytes()。

你的程序可以这样写：

import 'dart:io';

void main(List<String> args) {

  int? nuyCar = 0;
  double? fixSalary = 0.0;
  double? priceCollected = 0.0;

  print("Escreva o numero de carros vendidos pelo funcionario ");
  var line = stdin.readLineSync();
  if (line != null) {
    nuyCar = int.parse(line);
  }

  print("Escreva o salario fixo do funcionario: ");
  line = stdin.readLineSync();
  if (line != null) {
    fixSalary = double.parse(line);
  }

  print("Escreva o valor arrecadado das vendas do funcionario: ");
  line = stdin.readLineSync();
  if (line != null) {
    priceCollected = double.parse(line);
  }

  print(nuyCar);
  print(fixSalary);
  print(priceCollected);
}