参考在异步任务 [英] Ref in async Task

问题描述

我怎样才能通过参考在Windows Store应用的参数，异步方法？结果我正在寻找这样的事情：

How I can to pass a reference as a parameter to Async method in Windows Store App ?
I'm looking for something like this:

var a = DoThis(ref obj.value);

public async Task DoThis(ref int value)
{
    value = 10;
}

但是，错误：

异步方法不能有ref或out参数

Async methods cannot have ref or out parameters

有什么法子？

请注意：结果我需要传递准确obj.value。该方法通过将不同类型的对象，也可用于由同一类型的对象，一个对象，但我会把obj.val_1，obj.val_2或obj.val_10。所有的值将相同类型（前字符串）

Note:
I need to pass exactly obj.value. This method would be used by different types of objects, by same type of objects, by one object, but I will pass obj.val_1, obj.val_2 or obj.val_10. All values will be same type (for ex string)

推荐答案

如果你不计较一点点开销和你的对象的可能长寿命化，你可以通过传递setter和getter方法​​来模拟裁判的行为功能，像这样：

If you don't care about a little overhead and possibly prolonged lifetime of your objects, you could emulate the ref behavior by passing a setter and a getter method to the function, like this:

public async Task DoStuff(Func<int> getter, Action<int> setter)
{
    var value1 = getter();
    await DoSomeOtherAsyncStuff();
    setter(value1 * value1);
}

和调用它是这样的：

await DoStuff(() => obj.Value, x => obj.Value = x);

这篇关于参考在异步任务的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！