c# - 为什么在 finally block 中不允许等待？

Question

为什么 await 不允许出现在 finally block 中？

public async void Fn()
{
    try
    {
    }
    finally
    {
        await Task.Delay(4000);
    }
}

知道可以手动获取Awaiter

public void Fn()
{
    try
    {
    }
    finally
    {
        var awaiter = Task.Delay(4000).GetAwaiter();
     }
}

Answer 1

取自:Where can’t I use “await”?

Inside of a catch or finally block. You can use “await” inside of a try block, regardless of whether it has associated catch or finally blocks, but you can’t use it inside of the catch or finally blocks. Doing so would disrupt the semantics of CLR exception handling.

这显然在 C# 6.0 中不再适用

取自:A C# 6.0 Language Preview

C# 6.0 does away with this deficiency, and now allows await calls within both catch and finally blocks (they were already supported in try blocks)