c# - Parallel.ForEach 添加到列表

Question

我正在尝试运行多个连接到远程站点(通过网络)并返回通用列表的函数。但我想同时运行它们。

例如:

public static List<SearchResult> Search(string title)
{
    //Initialize a new temp list to hold all search results
    List<SearchResult> results = new List<SearchResult>();

    //Loop all providers simultaneously
    Parallel.ForEach(Providers, currentProvider =>
    {
        List<SearchResult> tmpResults = currentProvider.SearchTitle((title));

        //Add results from current provider
        results.AddRange(tmpResults);
    });

    //Return all combined results
    return results;
}

在我看来，多次插入“结果”可能会同时发生……这可能会使我的应用程序崩溃。

我怎样才能避免这种情况？

Answer 1

您可以使用 concurrent collection .

The System.Collections.Concurrent namespace provides several thread-safe collection classes that should be used in place of the corresponding types in the System.Collections and System.Collections.Generic namespaces whenever multiple threads are accessing the collection concurrently.

例如，您可以使用 ConcurrentBag因为您无法保证将添加项目的顺序。

Represents a thread-safe, unordered collection of objects.