我正在为一个朋友检查一些代码，并说他在try-finally块中使用了return语句。即使try块的其余部分没有触发，Finally部分中的代码仍然会触发吗?
例子:
public bool someMethod()
{
try
{
return true;
throw new Exception("test"); // doesn't seem to get executed
}
finally
{
//code in question
}
}
当前回答
这里有一个小测试:
class Class1
{
[STAThread]
static void Main(string[] args)
{
Console.WriteLine("before");
Console.WriteLine(test());
Console.WriteLine("after");
}
static string test()
{
try
{
return "return";
}
finally
{
Console.WriteLine("finally");
}
}
}
结果是:
before
finally
return
after
其他回答
引用自MSDN
Finally用于保证执行语句代码块，而不管前面的try块是如何退出的。
它也不会触发未捕获的异常，并运行在Windows服务托管的线程中
Finally在运行在Windows服务中的线程中不执行
是的。这实际上是最后一个陈述的主要观点。除非发生了一些灾难性的事情(内存不足，计算机拔插等)，finally语句应该始终执行。
这里有一个小测试:
class Class1
{
[STAThread]
static void Main(string[] args)
{
Console.WriteLine("before");
Console.WriteLine(test());
Console.WriteLine("after");
}
static string test()
{
try
{
return "return";
}
finally
{
Console.WriteLine("finally");
}
}
}
结果是:
before
finally
return
after
我意识到我迟到了，但在确实抛出异常的场景(与OP的示例不同)中，MSDN声明(https://msdn.microsoft.com/en-us/library/zwc8s4fz.aspx):“如果没有捕获异常，finally块的执行取决于操作系统是否选择触发异常unwind操作。”
The finally block is only guaranteed to execute if some other function (such as Main) further up the call stack catches the exception. This detail is usually not a problem because all run time environments (CLR and OS) C# programs run on free most resources a process owns when it exits (file handles etc.). In some cases it may be crucial though: A database operation half underway which you want to commit resp. unwind; or some remote connection which may not be closed automatically by the OS and then blocks a server.
