c# - 在 ASP.NET C# 中引发异常

Question

throw;只是说和throw ex;假设ex是你正在捕捉的例外有区别吗？

Answer 1

throw ex;将擦除您的堆栈跟踪。除非您要清除堆栈跟踪，否则不要这样做。只需使用throw;

Answer 2

这是一个简单的代码片段，有助于说明差异。不同之处在于 throw ex 将重置堆栈跟踪，就好像“ throw ex;”行是异常的来源一样。

代码：

using System;

namespace StackOverflowMess
{
    class Program
    {
        static void TestMethod()
        {
            throw new NotImplementedException();
        }

        static void Main(string[] args)
        {
            try
            {
                //example showing the output of throw ex
                try
                {
                    TestMethod();
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }

            Console.WriteLine();
            Console.WriteLine();

            try
            {
                //example showing the output of throw
                try
                {
                    TestMethod();
                }
                catch (Exception ex)
                {
                    throw;
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }

            Console.ReadLine();
        }
    }
}

输出（注意不同的堆栈跟踪）：

System.NotImplementedException: The method or operation is not implemented.
at StackOverflowMess.Program.Main(String[] args) in Program.cs:line 23

System.NotImplementedException: The method or operation is not implemented.
at StackOverflowMess.Program.TestMethod() in Program.cs:line 9
at StackOverflowMess.Program.Main(String[] args) in Program.cs:line 43

Answer 3

你有两个选择抛出；或将原始异常作为新异常的内部异常抛出。取决于你需要什么。