关于多线程问题

Question

 我有做了个扫IP的程序 发现单线程扫描的话非常慢
  于是我想让用户自行设置线程的个数
    做法是这样的 比如有4个线程      第一个线程 从1开始,......第四个线程从4开始  ,每次循环的增量就是线程的个数
    
线程的入口函数以及其显示的函数都一样 ,  现在问题是我该如何从入口函数里设置起始值,并将结果返回到窗体控件上(线程的个数不确定,是用户自行设置的)

Answer 1

List<Thread> _scaners=new List<Thread>();void Start(int threadCount){
    Thread t;
    for(int i=0;i<threadCount;i++){
        t=new Thread(new ThreadStart(Scan));
        t.Start();
        _scaners.add(t);
    }
}void Scan(){
    // 扫描
}

Answer 2

返回窗体要用委托，更新UI必须在UI线程里

Answer 3

//借用1楼
static int countThread = 0;void Start(int num)
{
    Thread t;
    for(int i=0;i<threadCount;i++)
    {
        t=new Thread(new ThreadStart(Scan));
        t.Start();
        countThread++;
    }
}static void Scan()
{
    // 扫描
}

Answer 4

 可能我的问题没有描述清楚  我的问题不是如何设置线程,而是线程入口函数的设置
void Scan(){
    // 扫描
}  就是这里,如何设置扫描的起始的值,因为每个线程扫描的超始值都是不同的,

Answer 5

    List<Thread> listThread = new List<Thread>();
    int threadCount=10;
    for(int i=0;i<threadCount;i++)
    {
        listThread.Add(new Thread(new ThreadStart(new Class1(i+1,threadCount).Scan)));
        listThread[i].Start();
    }Class Class1
{
    private int startNumber;
    private int threadCount;
    public class1(int startNumber,int threadCount)
    {
         this.startNumber=startNumber;
         this.threadCount=threadCount;
    }
    public void Scan()
    {
         for(int i=startNumber;i<255;i=i+threadCount)
         {
              //Do Ping Method
         }
    }
}

Answer 6

通过构造函数在ThreadStart里传递参数，自己想的，基本上没问题。应该还有更好的办法还没想到

Answer 7

ThreadPool.QueueUserWorkItem (WaitCallback, Object) 

Answer 8

采用事件AutoResetEvent are=new AutoResetEvent(false);MSDN:
using System;
using System.Threading;class CalculateTest
{
    static void Main()
    {
        Calculate calc = new Calculate();
        Console.WriteLine("Result = {0}.", 
            calc.Result(234).ToString());
        Console.WriteLine("Result = {0}.", 
            calc.Result(55).ToString());
    }
}class Calculate
{
    double baseNumber, firstTerm, secondTerm, thirdTerm;
    AutoResetEvent[] autoEvents;
    ManualResetEvent manualEvent;    // Generate random numbers to simulate the actual calculations.
    Random randomGenerator;    public Calculate()
    {
        autoEvents = new AutoResetEvent[]
        {
            new AutoResetEvent(false),
            new AutoResetEvent(false),
            new AutoResetEvent(false)
        };        manualEvent = new ManualResetEvent(false);
    }    void CalculateBase(object stateInfo)
    {
        baseNumber = randomGenerator.NextDouble();        // Signal that baseNumber is ready.
        manualEvent.Set();
    }    // The following CalculateX methods all perform the same
    // series of steps as commented in CalculateFirstTerm.    void CalculateFirstTerm(object stateInfo)
    {
        // Perform a precalculation.
        double preCalc = randomGenerator.NextDouble();        // Wait for baseNumber to be calculated.
        manualEvent.WaitOne();        // Calculate the first term from preCalc and baseNumber.
        firstTerm = preCalc * baseNumber * 
            randomGenerator.NextDouble();        // Signal that the calculation is finished.
        autoEvents[0].Set();
    }    void CalculateSecondTerm(object stateInfo)
    {
        double preCalc = randomGenerator.NextDouble();
        manualEvent.WaitOne();
        secondTerm = preCalc * baseNumber * 
            randomGenerator.NextDouble();
        autoEvents[1].Set();
    }    void CalculateThirdTerm(object stateInfo)
    {
        double preCalc = randomGenerator.NextDouble();
        manualEvent.WaitOne();
        thirdTerm = preCalc * baseNumber * 
            randomGenerator.NextDouble();
        autoEvents[2].Set();
    }    public double Result(int seed)
    {
        randomGenerator = new Random(seed);        // Simultaneously calculate the terms.
        ThreadPool.QueueUserWorkItem(
            new WaitCallback(CalculateBase));
        ThreadPool.QueueUserWorkItem(
            new WaitCallback(CalculateFirstTerm));
        ThreadPool.QueueUserWorkItem(
            new WaitCallback(CalculateSecondTerm));
        ThreadPool.QueueUserWorkItem(
            new WaitCallback(CalculateThirdTerm));        // Wait for all of the terms to be calculated.
        WaitHandle.WaitAll(autoEvents);        // Reset the wait handle for the next calculation.
        manualEvent.Reset();        return firstTerm + secondTerm + thirdTerm;
    }
}

Answer 9

较为简单可行的方法是,把扫描方法,封装成一个类.并定义一个属性,设置初始值,如:public class ScanInfo
    {
        private int startNumber;        
        public int StartNumber
        {
            get { return startNumber; }
            set { startNumber = value; }
        }        public void StartScan()
        {
            //从startNumber处开始扫描
        }
    }
//.........多线程调用
ScanInfo scan1 = new ScanInfo();
            scan1.StartNumber = 1;            Thread th1 = new Thread(new ThreadStart(scan1.StartScan));
            th1.Start();

Answer 10

接收的参数中是否有unicode字符？