如何从遇到错误但需要类型的方法返回

Question

假设我有一个返回 a 的方法，List<int>并且在获取它的过程中List<int>发生错误，因此无法收集数据。在方法中处理此异常的最佳方法是什么？该程序期望该方法返回一个列表，但由于无论出于何种原因发生了错误，它无法再执行此操作。我应该从方法返回什么？是否是调用代码捕获的自定义异常？

private List<int> GetData()

{

  List<in> theData = new List<int>();

  theData = ProcessThatGetsData(); //Error occurs in here

  return theData;  //What should be returned here?

}

Answer 1

如果你想捕获异常并处理它，一种方法是使用像这样的返回对象：&nbsp; &nbsp; &nbsp; &nbsp; private OperationResult GetData()&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; List<int> theData = new List<int>();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; try&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; theData = ProcessThatGetsData(); //Error occurs in here&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return new OperationResult { Success = true, Data = theData };&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; catch (Exception exc)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return new OperationResult { Success = false };&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return theData;&nbsp; //What should be returned here?&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; public class OperationResult&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; public bool Success { get; set; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; public IList<int> Data { get; set; }&nbsp; &nbsp; &nbsp; &nbsp; }这是一个选项，但是我的偏好是不将 try catch 语句放在此处，只放在您真正需要它的层……在这种情况下，您的代码不需要更改或担心返回类型。无论您在何处调用 GetData 方法，都将调用放在 try/catch 语句中，您应该没问题。请记住，始终在必须处理异常的级别处理异常，不要过度处理。

Answer 2

是否是调用代码捕获的自定义异常是的，只是让异常发生，调用方法负责处理异常（通过 try-catch 块）。