使用多线程的几种方式
(1)不需要传递参数,也不需要返回参数
ThreadStart是一个委托,这个委托的定义为void ThreadStart(),没有参数与返回值。
/// <summary>
/// 连接
///
</summary>
/// <param
name="host">服务器名称</param>
/// <param
name="port">服务器端口</param>
public void Connect(string host, int
port)
{
try
{
clientSock = new Socket(AddressFamily.InterNetwork, SocketType.Stream,
ProtocolType.Tcp);
clientSock.Connect(host,
port);
if (OnClientConn !=
null)
{
Session clientSession = new
Session(clientSock);
OnClientConn(this, new
NetEventArgs(clientSession));
}
Thread th = new Thread(new ThreadStart(ReceiveDataThread)); //也可简写为new
Thread(ThreadMethod);
th.Start();
//启动线程
}
catch
(Exception ex)
{
Debug.WriteLine(ex.Message);
throw;
}
}
/// <summary>
/// 从服务器接收数据
///
</summary>
private
void ReceiveDataThread()
{
while
(clientSock !=
null)
{
try
{
Session clientSession = new
Session(clientSock);
// Receives data from a bound Socket.
int bytesRec =
clientSock.Receive(recvDataBuffer);
// Converts byte array to string
clientSession.Datagram = this.recvCoder.GetEncodingString(recvDataBuffer,
bytesRec);
// Continues to read the data till data isn‘t available
while (clientSock.Available >
0)
{
bytesRec =
clientSock.Receive(recvDataBuffer);
clientSession.Datagram += this.recvCoder.GetEncodingString(recvDataBuffer,
bytesRec);
}
if(OnDataRecv!=null)
OnDataRecv(this, new
NetEventArgs(clientSession));
}
catch (Exception ex)
{
DisConnect();
Debug.WriteLine(ex.Message);
}
}
}
(2)使用匿名方法(常用)
使用匿名方法启动线程可以有多个参数和返回值,而且使用非常方便!
///
<summary>
///
弹出情报板消息框
///
</summary>
/// <param
name="name">情报板的名称</param>
/// <param
name="msg">要显示的信息</param>
private void _ucinfoboardview_OnShowAlert(string name, string
msg)
{
this.ThreadMsnStart(new
ThreadStart(delegate()
{
this.ThreadInfoBoard(name,
msg);
}));
}
/// <summary>
/// 执行多线程弹窗
///
</summary>
/// <param
name="threadstart">ThreadStart
委托</param>
private void
ThreadMsnStart(ThreadStart
threadstart)
{
Thread
tst = new
Thread(threadstart);
tst.Start();
}
/// <summary>
/// 线程入口
-- 情报板发布信息提示
///
</summary>
/// <param
name="name">情报板的名称</param>
/// <param
name="msg">情报板提示信息</param>
private void ThreadInfoBoard(string name, string
msg)
{
ClsMsgForMSN tt = new
ClsMsgForMSN();
tt.MyParentControl =
this;
tt.InfoBoardName =
name;
tt.InfoBoardMsg =
msg;
//定义一个委托实例,该实例执行打开窗口代码
MethodInvoker mi = new
MethodInvoker(tt.ShowInfoBoardMsg);
BeginInvoke(mi);
}
(3)使用委托开启多线程(多线程深入)
1、用委托(Delegate)的BeginInvoke和EndInvoke方法操作线程
BeginInvoke方法可以使用线程异步地执行委托所指向的方法。然后通过EndInvoke方法获得方法的返回值(EndInvoke方法的返回值就是被调用方法的返回值),或是确定方法已经被成功调用。
class Program
{
private delegate int NewTaskDelegate(int ms);
private static int newTask(int ms)
{
Console.WriteLine("任务开始");
Thread.Sleep(ms);
Random random = new Random();
int n = random.Next(10000);
Console.WriteLine("任务完成");
return n;
}
static void Main(string[] args)
{
NewTaskDelegate task = newTask;
IAsyncResult asyncResult = task.BeginInvoke(2000, null, null);
//EndInvoke方法将被阻塞2秒
int result = task.EndInvoke(asyncResult);
Console.WriteLine(result);
Console.Read();
}
}
2、使用IAsyncResult.IsCompleted属性来判断异步调用是否完成
class Program
{
private delegate int NewTaskDelegate(int ms);
private static int newTask(int ms)
{
Console.WriteLine("任务开始");
Thread.Sleep(ms);
Random random = new Random();
int n = random.Next(10000);
Console.WriteLine("任务完成");
return n;
}
static void Main(string[] args)
{
NewTaskDelegate task = newTask;
IAsyncResult asyncResult = task.BeginInvoke(2000, null, null);
//等待异步执行完成
while (!asyncResult.IsCompleted)
{
Console.Write("*");
Thread.Sleep(100);
}
// 由于异步调用已经完成,因此, EndInvoke会立刻返回结果
int result = task.EndInvoke(asyncResult);
Console.WriteLine(result);
Console.Read();
}
}
3、使用WaitOne方法等待异步方法执行完成
WaitOne的第一个参数表示要等待的毫秒数,在指定时间之内,WaitOne方法将一直等待,直到异步调用完成,并发出通知,WaitOne方法才返 回true。当等待指定时间之后,异步调用仍未完成,WaitOne方法返回false,如果指定时间为0,表示不等待,如果为-1,表示永远等待,直到 异步调用完成。
class Program
{
private delegate int NewTaskDelegate(int ms);
private static int newTask(int ms)
{
Console.WriteLine("任务开始");
Thread.Sleep(ms);
Random random = new Random();
int n = random.Next(10000);
Console.WriteLine("任务完成");
return n;
}
static void Main(string[] args)
{
NewTaskDelegate task = newTask;
IAsyncResult asyncResult = task.BeginInvoke(2000, null, null);
//等待异步执行完成
while (!asyncResult.AsyncWaitHandle.WaitOne(100, false))
{
Console.Write("*");
}
int result = task.EndInvoke(asyncResult);
Console.WriteLine(result);
Console.Read();
}
}
4、使用回调方式返回结果
要注意的是“my.BeginInvoke(3,300, MethodCompleted, my)”,BeginInvoke方法的参数传递方式:
前面一部分(3,300)是其委托本身的参数。
倒数第二个参数(MethodCompleted)是回调方法委托类型,他是回调方法的委托,此委托没有返回值,有一个IAsyncResult类型的参数,当method方法执行完后,系统会自动调用MethodCompleted方法。
最后一个参数(my)需要向MethodCompleted方法中传递一些值,一般可以传递被调用方法的委托,这个值可以使用IAsyncResult.AsyncState属性获得。
class Program
{
private delegate int MyMethod(int second, int millisecond);
//线程执行方法
private static int method(int second, int millisecond)
{
Console.WriteLine("线程休眠" + (second * 1000 + millisecond) + "毫秒");
Thread.Sleep(second * 1000 + millisecond);
Random random = new Random();
return random.Next(10000);
}
//回调方法
private static void MethodCompleted(IAsyncResult asyncResult)
{
if (asyncResult == null || asyncResult.AsyncState == null)
{
Console.WriteLine("回调失败!!!");
return;
}
int result = (asyncResult.AsyncState as MyMethod).EndInvoke(asyncResult);
Console.WriteLine("任务完成,结果:" + result);
}
static void Main(string[] args)
{
MyMethod my = method;
IAsyncResult asyncResult = my.BeginInvoke(3,300, MethodCompleted, my);
Console.WriteLine("任务开始");
Console.Read();
}
}
5、其他组件的BeginXXX和EndXXX方法
在其他的.net组件中也有类似BeginInvoke和EndInvoke的方法,如System.Net.HttpWebRequest类的BeginGetResponse和EndGetResponse方法。其使用方法类似于委托类型的BeginInvoke和EndInvoke方法,例如:
class Program
{
//回调函数
private static void requestCompleted(IAsyncResult asyncResult)
{
if (asyncResult == null || asyncResult.AsyncState==null)
{
Console.WriteLine("回调失败");
return;
}
HttpWebRequest hwr = asyncResult.AsyncState as HttpWebRequest;
HttpWebResponse response = (HttpWebResponse)hwr.EndGetResponse(asyncResult);
StreamReader sr = new StreamReader(response.GetResponseStream());
string str = sr.ReadToEnd();
Console.WriteLine("返回流长度:"+str.Length);
}
static void Main(string[] args)
{
HttpWebRequest request =
(HttpWebRequest)WebRequest.Create("http://www.baidu.com");
//异步请求
IAsyncResult asyncResult = request.BeginGetResponse(requestCompleted, request);
Console.WriteLine("任务开始");
Console.Read();
}
}