使用C＃.NET動態生成新線程

Question

如何以有效和受控的方式動態生成線程？線程將根據每個XML主機ID動態創建。

例子：

samplethread1 for hostid:-1 
samplethread2 for hostid:-2 

因爲我不能依靠主機ID數我需要讓我的代碼動態：建議我怎麼能有每個線程的控制。

拿到了一塊示例XML代碼：

<?xml version="1.0" standalone="yes"?> 
    <HOSTS> 
    <Host id = '1'> 
     <Extension>txt</Extension> 
     <FolderPath>C:/temp</FolderPath> 
    </Host> 
    <Host id = '2'> 
     <Extension>rar</Extension> 
     <FolderPath>C:/Sample</FolderPath> 
    </Host> 
    </HOSTS> 

Answer 1

我不得不承認，這個問題還不是特別清楚。但是如果你正在爲每個主機創建一個新的線程，那麼這個怎麼樣？這是使用.NET 4.0 Task Parallel Library。從.NET 4.0開始，這是一個簡單的方法來利用處理器的併發功能。

static void Main(string[] args) 
{ 
    var currentDir = Directory.GetCurrentDirectory(); 
    var xDoc = XDocument.Load(string.Format(Path.Combine(currentDir, "Hosts.xml"))); 
    var taskFactory = new TaskFactory(); 

    foreach (XElement host in xDoc.Descendants("Host")) 
    { 
     var hostId = (int) host.Attribute("id"); 
     var extension = (string) host.Element("Extension"); 
     var folderPath = (string) host.Element("FolderPath"); 
     taskFactory.StartNew(() => DoWork(hostId, extension, folderPath)); 
    } 
    //Carry on with your other work 
} 

static void DoWork(int hostId, string extension, string folderPath) 
{ 
    //Do stuff here 
} 

如果您使用.NET 3.5或以前的，那麼你可以自己創建線程：

static void Main(string[] args) 
{ 
    var currentDir = Directory.GetCurrentDirectory(); 
    var xDoc = XDocument.Load(string.Format(Path.Combine(currentDir, "Hosts.xml"))); 
    var threads = new List<Thread>(); 

    foreach (XElement host in xDoc.Descendants("Host")) 
    { 
     var hostID = (int) host.Attribute("id"); 
     var extension = (string) host.Element("Extension"); 
     var folderPath = (string) host.Element("FolderPath"); 
     var thread = new Thread(DoWork) 
         { 
          Name = string.Format("samplethread{0}", hostID) 
         }; 
     thread.Start(new FileInfo 
         { 
          HostId = hostID, 
          Extension = extension, 
          FolderPath = folderPath 
         }); 
     threads.Add(thread); 
    } 
    //Carry on with your other work, then wait for worker threads 
    threads.ForEach(t => t.Join()); 
} 

static void DoWork(object threadState) 
{ 
    var fileInfo = threadState as FileInfo; 
    if (fileInfo != null) 
    { 
     //Do stuff here 
    } 
} 

class FileInfo 
{ 
    public int HostId { get; set; } 
    public string Extension { get; set; } 
    public string FolderPath { get; set; } 
} 

這對我來說仍然是the best guide to Threading。

編輯

所以這是什麼，我認爲你是在您的評論獲得基於任務的版本？

static void Main() 
{ 
    var currentDir = Directory.GetCurrentDirectory(); 
    var xDoc = XDocument.Load(string.Format(Path.Combine(currentDir, "Hosts.xml"))); 
    var taskFactory = new TaskFactory(); 

    //I'm assuming this ID would normally be user input, or be passed from some other external source 
    int hostId = 2; 

    taskFactory.StartNew(() => DoWork(hostId, xDoc)); 
    //Carry on with your other work 
} 

static void DoWork(int hostId, XDocument hostDoc) 
{ 
    XElement foundHostElement = (from hostElement in hostDoc.Descendants("Host") 
            where (int)hostElement.Attribute("id") == hostId 
            select hostElement).First(); 
    var extension = (string)foundHostElement.Element("Extension"); 
    var folderPath = (string)foundHostElement.Element("FolderPath"); 
    //Do stuff here 
} 

Answer 2

如果你不想保持陣列處理的你可以「射後不理」，所以我會建議使用「線程池」：

01：在 http://msdn.microsoft.com/en-us/library/3dasc8as(v=vs.80).aspx，如果你想創建你可以做一些像陣列

ThreadPool.QueueUserWorkItem(); 

更多信息創建和運行的線程

List<Thread> threads = new List<Thread>(); 
threads.Add(new Thread()); //Create the thread with your parameters here 

例如：http://msdn.microsoft.com/en-us/library/system.threading.thread.aspx