相关疑难解决方法(0)

在metro应用程序中,我需要执行许多WCF调用.有大量的调用,所以我需要在并行循环中进行调用.问题是并行循环在WCF调用完成之前退出.

你会如何重构这个按预期工作？

var ids = new List<string>() { "1", "2", "3", "4", "5", "6", "7", "8", "9", "10" };
var customers = new  System.Collections.Concurrent.BlockingCollection<Customer>();

Parallel.ForEach(ids, async i =>
{
    ICustomerRepo repo = new CustomerRepo();
    var cust = await repo.GetCustomer(i);
    customers.Add(cust);
});

foreach ( var customer in customers )
{
    Console.WriteLine(customer.ID);
}

Console.ReadKey();

让我们说我有几个任务:

void Sample(IEnumerable<int> someInts)
{
    var taskList = someInts.Select(x => DownloadSomeString(x));
}

async Task<string> DownloadSomeString(int x) {...}

我想得到第一个成功任务的结果.所以,基本的解决方案是写下这样的东西:

var taskList = someInts.Select(x => DownloadSomeString(x));
string content = string.Empty;
Task<string> firstOne = null;
while (string.IsNullOrWhiteSpace(content)){
    try
    {
        firstOne = await Task.WhenAny(taskList);
        if (firstOne.Status != TaskStatus.RanToCompletion)
        {
            taskList = taskList.Where(x => x != firstOne);
            continue;
        }
        content = await firstOne;
    }
    catch(...){taskList = taskList.Where(x => x != firstOne);}
}

但是这个解决方案似乎运行N+( - N1)+ .. + K任务.哪里N是someInts.Count …