相关疑难解决方法(0)

我从这个 链接复制下面的代码.但是当我编译这段代码时,我得到的入口点不能用'async'修饰符标记.如何使这段代码可编辑？

class Program
{
    static async void Main(string[] args)
    {
        Task<string> getWebPageTask = GetWebPageAsync("http://msdn.microsoft.com");

        Debug.WriteLine("In startButton_Click before await");
        string webText = await getWebPageTask;
        Debug.WriteLine("Characters received: " + webText.Length.ToString()); 
    }

    private static async Task<string> GetWebPageAsync(string url)
    {
        // Start an async task. 
        Task<string> getStringTask = (new HttpClient()).GetStringAsync(url);

        // Await the task. This is what happens: 
        // 1. Execution immediately returns to the calling method, returning a 
        //    different task from the task created in the previous statement. …

我有一个程序,没有任何目的,但帮助我了解如何异步和等待工作.它是一个控制台应用程序,它解析XML并等待返回名称,无论是姓氏还是名字.这是代码:

static void Main(string[] args)
{
     Task<string> name = GetFirstParsedName();
     name.Wait();
     if (name.IsCompleted)
     {
         Console.WriteLine(name.Result);
     }

     Console.ReadLine();
 }

static async Task<string> GetFirstParsedName()
{
  string xmlSnippet = @"<person>
<FirstName>Chamir</FirstName>
<Surname>Bodasing</Surname>
<Gender>Male</Gender>
<Nationality>South African</Nationality></person>";

  XmlDocument xmlDoc = new XmlDocument();
  xmlDoc.LoadXml(xmlSnippet);

  XmlParser xmlParser = new XmlParser();
  Task<string> t_GetFirstName = xmlParser.GetFirstName(xmlDoc);
  Task<string> t_GetSurname = xmlParser.GetSurname(xmlDoc);  

  Task<string> t_firstReturnedName = await Task.WhenAny(new Task<string>[] { t_GetFirstName, t_GetSurname });

  string firstReturnedName = await t_firstReturnedName;
  return firstReturnedName;    
}

static async Task<string> GetFirstName(XmlDocument personXml)
{
  string firstName = personXml.SelectSingleNode("//FirstName").InnerText;
  await …

我在Windows(.NET 4.5.1)和Linux(Mono 4.0.1)上尝试了这个简单的ASP.net 5控制台应用程序,两次都有相同的结果.

注意:我称之为ASP.net 5控制台应用程序,因为这是在Visual Studio中调用到RC的内容.现在它被称为控制台应用程序(包),但它仍然使用来自https://github.com/aspnet/dnx的 DNX :)

我的Program.cs:

using System;
using System.Threading.Tasks;

namespace ConsoleApplication
{
    public class Program
    {
        public async void Main(String[] args)
        {
            #if DNX451
            AppDomain.CurrentDomain.UnhandledException += 
                (s, e) => Console.WriteLine(e);
            #endif

            try
            {
                await Task.Delay(1000);
                Console.WriteLine("After Task.Delay");
            }
            finally
            {
                Console.WriteLine("Inside Finally");
            }
        }
    }
}

我的project.json:

{
    "version": "1.0.0-*",
    "dependencies": {},
    "commands": {
        "ConsoleApplication": "ConsoleApplication"
    },
    "frameworks": {
        "dnx451": {}
    }
}

当使用1.0.0-beta4 CLR或运行时1.0.0-beta5-11904 CLR …