在.net中为我们提供了两种启动线程的方式,一种是不带参数的启动方式,另一种是带参数的启动的方式。
1:不带参数的启动方式,可以使用ThreadStart来实例化Thread,ThreadStart是在.Net Framework 中已经定义好的委托,ThreadStart定义为:
public delegate void ThreadStart();
使用方法如下面的代码:
static void Main(string[] args)
{
Demo demo = new Demo();
Thread t = new Thread(new ThreadStart(demo.Run));
t.Name = "NoParameterThread";
t.Start();
}
public class Demo
{
int interval = 1000;
/// <summary>
/// 不带参数的启动方法
/// </summary>
public void Run()
{
for (int i = 0; i < 10; i++)
{
DoSomething();
}
}
private void DoSomething()
{
Console.WriteLine(string.Format("当前线程:{0},当前系统时间为:{1}", Thread.CurrentThread.Name, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));
Thread.Sleep(interval);
}
}
2:带参数的启动方法,就要使用ParameterizedThreadStart委托来实例化Thread了,和ThreadStart一样的是它也是线程启动时要执行的方法,和ThreadStart不同的是,它在实例化时可以用一个带有一个Object参数的方法作为构造函数的参数,而实例化ThreadStart时所用到的方法是没有参数的。ParameterizedThreadStart定义为:
public delegate void ParameterizedThreadStart(object obj);
使用方法如下面的代码:
public class Demo
{
int interval = 1000;
private void DoSomething()
{
Console.WriteLine(string.Format("当前线程:{0},当前系统时间为:{1}", Thread.CurrentThread.Name, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));
Thread.Sleep(interval);
}
/// <summary>
/// 带参数的启动方法
/// </summary>
/// <param name="param"></param>
public void Run(object param)
{
if (param == null)
return;
int.TryParse(param.ToString(), out interval);
for (int i = 0; i < 10; i++)
{
DoSomething();
}
}
}
static void Main(string[] args)
{
Demo demo = new Demo();
Thread parameterThread = new Thread(new ParameterizedThreadStart(demo.Run));
parameterThread.Name = "ParameterThread";
parameterThread.Start(2000);
}
3:在很多时候,我们遇到的情况是要传递多个参数,注意到ParameterizedThreadStart委托的参数类型是一个Object对象,为什么是Object这样的参数呢?很简单,因为在.net中Object是所有类型的基类。这样我们可以声明一个类,为这个类增加属性,这些属性也就是参数。
使用方法如下面的代码:
static void Main(string[] args)
{
Demo demo = new Demo();
ThreadParamter p = new ThreadParamter(2000,100);
Thread multiParameterThread = new Thread(new ParameterizedThreadStart(demo.CustomerParamterRun));
multiParameterThread.Name = "MultiParameterThread";
multiParameterThread.Start(p);
}
public class Demo
{
/// <summary>
/// 带多个参数的启动方法
/// </summary>
/// <param name="param"></param>
public void CustomerParamterRun(object param)
{
if (param == null)
return;
ThreadParamter p = param as ThreadParamter;
if (p != null)
{
for (int i = 0; i < p.LoopCount; i++)
{
Console.WriteLine(string.Format("当前线程:{0},当前系统时间为:{1}", Thread.CurrentThread.Name, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));
Thread.Sleep(p.Interval);
}
}
}
}
public class ThreadParamter
{
public int Interval { get; set; }
public int LoopCount { get; set; }
public ThreadParamter()
{ }
public ThreadParamter(int interval, int loopCount)
{
this.Interval = interval;
this.LoopCount = loopCount;
}
}
4:在遇到业务非常复杂的时候,上面写法还是有问题,封装不够好,我们可以使用装饰模式,对上面的代码进行改进。这样业务发生改变的时候,我们只需要修改核心的实现部分,调用的方法可以不用做任何修改,而且调用方法的代码非常简洁。
修改后的代码如下:
static void Main(string[] args) { DecoratorThread t = new DecoratorThread(new ThreadParamter(2000, 100)); t.Start(); }
public class ThreadParamter
{
public int Interval { get; set; }
public int LoopCount { get; set; }
public ThreadParamter()
{ }
public ThreadParamter(int interval, int loopCount)
{
this.Interval = interval;
this.LoopCount = loopCount;
}
}
/// <summary>
/// 使用装饰模式来实现多个参数的
/// </summary>
public class DecoratorThread
{
private ThreadParamter threadParamter;
private Thread thread;
public DecoratorThread(ThreadParamter threadParamter)
{
this.threadParamter = threadParamter;
thread = new Thread(new ThreadStart(Run));
thread.Name = "DecoratorThread";
}
public void Start()
{
if (thread != null)
{
thread.Start();
}
}
private void Run()
{
for (int i = 0; i < threadParamter.LoopCount; i++)
{
Console.WriteLine(string.Format("当前线程:{0},当前系统时间为:{1}", Thread.CurrentThread.Name, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));
Thread.Sleep(threadParamter.Interval);
}
}
}