首页 > 代码库 > C#中关于异步的三种写法
C#中关于异步的三种写法
1 投票
IAsyncResult ar = d1.BeginInvoke(1, 3000, null, null);
while (!ar.IsCompleted)
class Program
{
static int TakesAWhile(int data, int ms)
{
Console.WriteLine("TakesAWhile started");
Thread.Sleep(ms);
Console.WriteLine("TakesAWhile completed");
return ++data;
}
public delegate int TakesAWhileDelegate(int data, int ms);
static void Main(string[] args)
{
TakesAWhileDelegate d1 = TakesAWhile;
IAsyncResult ar = d1.BeginInvoke(1, 3000, null, null);
while (!ar.IsCompleted)
{
// doing something else
Console.Write(".");
Thread.Sleep(50);
}
int result = d1.EndInvoke(ar);
Console.WriteLine("result: {0}", result);
Console.ReadLine();
}
}
2 等待句柄
class Program
{
static int TakesAWhile(int data, int ms)
{
Console.WriteLine("TakesAWhile started");
Thread.Sleep(ms);
Console.WriteLine("TakesAWhile completed");
return ++data;
}
public delegate int TakesAWhileDelegate(int data, int ms);
static void Main(string[] args)
{
TakesAWhileDelegate d1 = TakesAWhile;
IAsyncResult ar = d1.BeginInvoke(1, 3000, null, null);
int i = 0;
while (true)
{
Console.Write(i++);
Console.Write(".");
if (ar.AsyncWaitHandle.WaitOne(50, true))
{
Console.WriteLine("Can get the result now");
break;
}
}
int result = d1.EndInvoke(ar);
Console.WriteLine("result: {0}", result);
}
}
3 回调 pdf533 p509
class Program
{
static int TakesAWhile(int data, int ms)
{
Console.WriteLine("TakesAWhile started");
Thread.Sleep(ms);
Console.WriteLine("TakesAWhile completed");
return ++data;
}
public delegate int TakesAWhileDelegate(int data, int ms);
static void Main(string[] args)
{
TakesAWhileDelegate d1 = TakesAWhile;
IAsyncResult ar = d1.BeginInvoke(1, 3000, TakesAWhileCompleted, d1);
for (int i = 0; i < 100; i++)
{
Console.Write(".");
Thread.Sleep(50);
}
Console.ReadLine();
}
static void TakesAWhileCompleted(IAsyncResult ar)
{
if (ar == null) throw new ArgumentNullException("ar");
TakesAWhileDelegate d1 = ar.AsyncState as TakesAWhileDelegate;
Trace.Assert(d1 != null, "Invalid object type");
int result = d1.EndInvoke(ar);
Console.WriteLine("result: {0}", result);
}
}
通过lambda表达式来实现：
static int TakesAWhile(int data, int ms)
{
Console.WriteLine("TakesAWhile started");
Thread.Sleep(ms);
Console.WriteLine("TakesAWhile completed");
return ++data;
}
public delegate int TakesAWhileDelegate(int data, int ms);
static void Main(string[] args)
{
TakesAWhileDelegate d1 = TakesAWhile;
d1.BeginInvoke(1, 3000,
ar =>
{
int result = d1.EndInvoke(ar);
Console.WriteLine("result: {0}", result);
},
null);
for (int i = 0; i < 100; i++)
{
Console.Write(".");
Thread.Sleep(50);
}
Console.ReadLine();
}
var completed = new AutoResetEvent(false);
var args = new SocketAsyncEventArgs();
args.RemoteEndPoint = endpoint;
args.Completed += OnConnectCompleted;
args.UserToken = completed;
socket.ConnectAsync(args);
if (!completed.WaitOne(timeout) || !socket.Connected)
{
using (socket)
{
throw new TimeoutException("Could not connect to " + endpoint);
}
}
C#中关于异步的三种写法