非通用TaskCompletionSource或替代 [英] Non-Generic TaskCompletionSource or alternative

问题描述

我正与一个警告窗口（WPF的Telerik），它通常异步显示（code继续运行时，它是开放的），我希望把它同步使用异步/等待。

I'm working with an alert window (Telerik WPF) that is normally displayed asynchronously ( code continues running while it is open) and I want to make it synchronous by using async/await.

我有这个与 TaskCompletionSource 工作，但这个类是通用的，返回一个对象如任务＆LT;布尔＆GT; 时，所有我想要的是一个普通的工作没有返回值。

I have this working with TaskCompletionSource but that class is generic and returns an object like Task<bool> when all I want is a plain Task with no return value.

public Task<bool> ShowAlert(object message, string windowTitle)
{
    var dialogParameters = new DialogParameters { Content = message };

    var tcs = new TaskCompletionSource<bool>();
    dialogParameters.Closed += (s, e) => tcs.TrySetResult(true);

    RadWindow.Alert(dialogParameters);

    return tcs.Task;
}

在code调用该方法

The code that calls that method is

await MessageBoxService.ShowAlert("The alert text.")

我怎样才能返回一个非一般的任务，其功能类似于在那里我可以等待，直到 dialogParameters.Closed 事件触发？我明白，我可以忽略布尔是本code返回。我要寻找不同的解决方案比。

How can I return a non-generic Task that functions similarly where I can await it until dialogParameters.Closed event fires? I understand that I could just ignore the bool that is being returned in this code. I am looking for a different solution than that.

推荐答案

该方法可改为：

public Task ShowAlert(object message, string windowTitle)

任务＆LT;布尔＆GT; 从任务继承这样你就可以返回任务＆LT;布尔＆GT; ，而只露出工作给调用者

Task<bool> inherits from Task so you can return Task<bool> while only exposing Task to the caller

编辑：

我找到了微软的文档，<一个href="http://www.microsoft.com/en-us/download/details.aspx?id=19957">http://www.microsoft.com/en-us/download/details.aspx?id=19957,斯蒂芬Toub题为基于任务的异步模式'，它有以下摘录建议同样的模式。

I found a Microsoft document, http://www.microsoft.com/en-us/download/details.aspx?id=19957, by Stephen Toub titled 'The Task-based Asynchronous pattern' and it has the following excerpt that recommends this same pattern.

有没有非泛型对口TaskCompletionSource＆LT; TResult>。然而，任务和LT; TResult>源于任务，因此，一般TaskCompletionSource＆LT; TResult>可用于I / O密集​​型的，仅仅通过利用源与虚拟TResult返回任务的方法（布尔是一个不错的缺省选择，和如果一个开发人员关注的任务的消费者它向下转换到一个任务＆LT; TResult>，私人TResult类型都可以使用）

There is no non-generic counterpart to TaskCompletionSource<TResult>. However, Task<TResult> derives from Task, and thus the generic TaskCompletionSource<TResult> can be used for I/O-bound methods that simply return a Task by utilizing a source with a dummy TResult (Boolean is a good default choice, and if a developer is concerned about a consumer of the Task downcasting it to a Task<TResult>, a private TResult type may be used)

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