但是问题在于，它在等待之后仍然在UI线程中运行.

But the problem is that it still runs in the UI thread after the await.

是的，会的.这是 async / await 的全部内容的一半-您可以返回到正确的上下文.

Yes, it would. That's half the whole point of async/await - that you get to come back to the right context.

听起来好像您真的应该启动一个新线程(或者***使用 Task< T> )进行后台操作(如果无法避免)阻止IO.然后，您可以在异步方法中使用结果:

It sounds like you really should start a new thread (or preferably, use a Task<T>) for the background operation, if you can't avoid the blocking IO. Then you can use the result in an async method:

async Task Foo(...)
{
    string result = await Task.Run(...);
    // Now update the UI with the result
}