Asyncawait

请参阅下面的一个简单示例,了解如何使用 async / await 在后台进程中执行一些时间密集的操作,同时保持执行其他一些不需要等待时间密集的东西完成的东西的选项。

但是,如果以后需要使用时间密集型方法的结果,可以通过等待执行来完成此操作。

public async Task ProcessDataAsync()
{
    // Start the time intensive method
    Task<int> task = TimeintensiveMethod(@"PATH_TO_SOME_FILE");

    // Control returns here before TimeintensiveMethod returns
    Console.WriteLine("You can read this while TimeintensiveMethod is still running.");

    // Wait for TimeintensiveMethod to complete and get its result
    int x = await task;
    Console.WriteLine("Count: " + x);
}

private async Task<int> TimeintensiveMethod(object file)
{
    Console.WriteLine("Start TimeintensiveMethod.");

    // Do some time intensive calculations...
    using (StreamReader reader = new StreamReader(file.ToString()))
    {
        string s = await reader.ReadToEndAsync();

        for (int i = 0; i < 10000; i++)
            s.GetHashCode();
    }
    Console.WriteLine("End TimeintensiveMethod.");

    // return something as a "result"
    return new Random().Next(100);
}