c# - 跳出 finally block

Question

我正在寻找关键字或干净的方式来不使用选择语句退出finally block 。考虑以下示例:

private bool AtteptToDoSomething()
{
    try
    {
        MethodThatCouldFail();
        return true;
    }
    catch
    {
        return false;
    }
    finally
    {
        //Jump out of function here?            

        //... to avoid executing this under certain conditions
        DoSomethingFinalizing();
    }
}

失败的尝试:

finally
{
    return;
    break;
    continue;
    goto ExitSymbol;
    //This works, but would require a second try-catch block
    throw new Exception();
}

上述示例的编译器错误包括:

Control cannot leave the body of a finally clause

和

Cannot jump out of the finally block

现在很清楚，finally block 不能通过任何常规 方式转移控制。

有a pretty good explanation why this won't work with continue ，但不幸的是，这不是为什么在任何其他情况下都不能这样做。

是否有任何(基于 CLR 或 C# 的)不允许/不可能这样做的原因？

除 throw 外，此限制是否有任何异常(exception)情况？

Answer 1

你不能。

这是设计使然，并在 C# 规范中进行了描述:8.10 The try statement.

It is a compile-time error for a break, continue, or goto statement to transfer control out of a finally block. When a break, continue, or goto statement occurs in a finally block, the target of the statement must be within the same finally block, or otherwise a compile-time error occurs.

It is a compile-time error for a return statement to occur in a finally block.

要制作你想要的东西，你可以这样做:

try {}
catch {}
finally
{
    Magic();
}

然后

  void Magic()
  {     
        if (x == y)
           return;
        else
           a = b;    
  }