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分享高手请进!!! .net下的事件是同步还是异步？
1，比如函数a触发事件e,事件处理函数h,那么h和a的剩余部分是不是同步执行的？
2，如果是异步的，是不是在同一线程？
2，如果是异步的，是不是在同一线程？
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sarcophile 2003-10-02
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高。
pcnetman 2003-10-02
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异步通知：轮询
public void DoWork()
{
//...
Console.WriteLine("Worker: work completed");
if( completed != null )
{
foreach( WorkCompleted wc in completed.GetInvocationList() )
{
IAsyncResult res = wc.BeginInvoke(null, null);
while( !res.IsCompleted ) System.Threading.Thread.Sleep(1);
int grade = wc.EndInvoke(res);
Console.WriteLine("Worker grade= " + grade);
}
}
}
【译注：下面给出本节例子完整代码：
using System;
delegate void WorkStarted();
delegate void WorkProgressing();
delegate int WorkCompleted();
class Worker
{
public void DoWork()
{
Console.WriteLine("Worker: work started");
if( started != null ) started();
Console.WriteLine("Worker: work progressing");
if( progressing != null ) progressing();
Console.WriteLine("Worker: work completed");
if( completed != null )
{
foreach( WorkCompleted wc in completed.GetInvocationList() )
{
IAsyncResult res = wc.BeginInvoke(null, null);
while( !res.IsCompleted ) System.Threading.Thread.Sleep(1);
int grade = wc.EndInvoke(res);
Console.WriteLine("Worker grade= " + grade);
}
}
}
public event WorkStarted started ;
public event WorkProgressing progressing;
public event WorkCompleted completed;
}
class Boss
{
public int WorkCompleted()
{
System.Threading.Thread.Sleep(3000);
Console.WriteLine("Better...");
return 6; /* out of 10 */
}
}
class Universe
{
static void WorkerStartedWork()
{
Console.WriteLine("Universe notices worker starting work");
}
static int WorkerCompletedWork()
{
System.Threading.Thread.Sleep(4000);
Console.WriteLine("Universe is pleased with worker's work");
return 7;
}
static void Main()
{
Worker peter = new Worker();
Boss boss = new Boss();
peter.completed += new WorkCompleted(boss.WorkCompleted);
peter.started += new WorkStarted(Universe.WorkerStartedWork);
peter.completed += new WorkCompleted(Universe.WorkerCompletedWork);
peter.DoWork();
Console.WriteLine("Main: worker completed work");
Console.ReadLine();
}
}
/*
以下是上段程序输出结果：
Worker: work started
Universe notices worker starting work
Worker: work progressing
Worker: work completed
Better...
Worker grade = 6
Universe pleased with worker's work
Worker grade = 7
Main: worker completed work //【译注：注意这个结果到最后才输出，下一节首句意思即是如此】
*/
】
异步通知：委托
public void DoWork()
{
//...
Console.WriteLine("Worker: work completed");
if( completed != null )
{
foreach( WorkCompleted wc in completed.GetInvocationList() )
{
wc.BeginInvoke(new AsyncCallback(WorkGraded), wc);
}
}
}
private void WorkGraded(IAsyncResult res)
{
WorkCompleted wc = (WorkCompleted)res.AsyncState;
int grade = wc.EndInvoke(res);
Console.WriteLine("Worker grade= " + grade);
}
【译注：下面给出本节例子完整代码：
using System;
delegate void WorkStarted();
delegate void WorkProgressing();
delegate int WorkCompleted();
class Worker
{
public void DoWork()
{
Console.WriteLine("Worker: work started");
if( started != null ) started();
Console.WriteLine("Worker: work progressing");
if( progressing != null ) progressing();
Console.WriteLine("Worker: work completed");
if( completed != null )
{
foreach( WorkCompleted wc in completed.GetInvocationList() )
{
wc.BeginInvoke(new AsyncCallback(WorkGraded), wc);
}
}
}
private void WorkGraded(IAsyncResult res)
{
WorkCompleted wc = (WorkCompleted)res.AsyncState;
int grade = wc.EndInvoke(res);
Console.WriteLine("Worker grade= " + grade);
}
public event WorkStarted started ;
public event WorkProgressing progressing;
public event WorkCompleted completed;
}
class Boss
{
public int WorkCompleted()
{
System.Threading.Thread.Sleep(3000);
Console.WriteLine("Better...");
return 6; /* out of 10 */
}
}
class Universe
{
static void WorkerStartedWork()
{
Console.WriteLine("Universe notices worker starting work");
}
static int WorkerCompletedWork()
{
System.Threading.Thread.Sleep(4000);
Console.WriteLine("Universe is pleased with worker's work");
return 7;
}
static void Main()
{
Worker peter = new Worker();
Boss boss = new Boss();
peter.completed += new WorkCompleted(boss.WorkCompleted);
peter.started += new WorkStarted(Universe.WorkerStartedWork);
peter.completed += new WorkCompleted(Universe.WorkerCompletedWork);
peter.DoWork();
Console.WriteLine("Main: worker completed work");
Console.ReadLine();
}
}
/*以下是上段程序输出结果：
Worker: work started
Universe notices worker starting work
Worker: work progressing
Worker: work completed
Main: worker completed work //【译注：异步委托发生了效果，因此这一行先输出啦J】
Better...
Worker grade = 6
Universe pleased with worker's work
Worker grade = 7
*/
事件是引发的，
是同步的，
可以通过事件（本身是被特殊支持的对象）的方法来实现异步。
public void DoWork()
{
//...
Console.WriteLine("Worker: work completed");
if( completed != null )
{
foreach( WorkCompleted wc in completed.GetInvocationList() )
{
IAsyncResult res = wc.BeginInvoke(null, null);
while( !res.IsCompleted ) System.Threading.Thread.Sleep(1);
int grade = wc.EndInvoke(res);
Console.WriteLine("Worker grade= " + grade);
}
}
}
【译注：下面给出本节例子完整代码：
using System;
delegate void WorkStarted();
delegate void WorkProgressing();
delegate int WorkCompleted();
class Worker
{
public void DoWork()
{
Console.WriteLine("Worker: work started");
if( started != null ) started();
Console.WriteLine("Worker: work progressing");
if( progressing != null ) progressing();
Console.WriteLine("Worker: work completed");
if( completed != null )
{
foreach( WorkCompleted wc in completed.GetInvocationList() )
{
IAsyncResult res = wc.BeginInvoke(null, null);
while( !res.IsCompleted ) System.Threading.Thread.Sleep(1);
int grade = wc.EndInvoke(res);
Console.WriteLine("Worker grade= " + grade);
}
}
}
public event WorkStarted started ;
public event WorkProgressing progressing;
public event WorkCompleted completed;
}
class Boss
{
public int WorkCompleted()
{
System.Threading.Thread.Sleep(3000);
Console.WriteLine("Better...");
return 6; /* out of 10 */
}
}
class Universe
{
static void WorkerStartedWork()
{
Console.WriteLine("Universe notices worker starting work");
}
static int WorkerCompletedWork()
{
System.Threading.Thread.Sleep(4000);
Console.WriteLine("Universe is pleased with worker's work");
return 7;
}
static void Main()
{
Worker peter = new Worker();
Boss boss = new Boss();
peter.completed += new WorkCompleted(boss.WorkCompleted);
peter.started += new WorkStarted(Universe.WorkerStartedWork);
peter.completed += new WorkCompleted(Universe.WorkerCompletedWork);
peter.DoWork();
Console.WriteLine("Main: worker completed work");
Console.ReadLine();
}
}
/*
以下是上段程序输出结果：
Worker: work started
Universe notices worker starting work
Worker: work progressing
Worker: work completed
Better...
Worker grade = 6
Universe pleased with worker's work
Worker grade = 7
Main: worker completed work //【译注：注意这个结果到最后才输出，下一节首句意思即是如此】
*/
】
异步通知：委托
public void DoWork()
{
//...
Console.WriteLine("Worker: work completed");
if( completed != null )
{
foreach( WorkCompleted wc in completed.GetInvocationList() )
{
wc.BeginInvoke(new AsyncCallback(WorkGraded), wc);
}
}
}
private void WorkGraded(IAsyncResult res)
{
WorkCompleted wc = (WorkCompleted)res.AsyncState;
int grade = wc.EndInvoke(res);
Console.WriteLine("Worker grade= " + grade);
}
【译注：下面给出本节例子完整代码：
using System;
delegate void WorkStarted();
delegate void WorkProgressing();
delegate int WorkCompleted();
class Worker
{
public void DoWork()
{
Console.WriteLine("Worker: work started");
if( started != null ) started();
Console.WriteLine("Worker: work progressing");
if( progressing != null ) progressing();
Console.WriteLine("Worker: work completed");
if( completed != null )
{
foreach( WorkCompleted wc in completed.GetInvocationList() )
{
wc.BeginInvoke(new AsyncCallback(WorkGraded), wc);
}
}
}
private void WorkGraded(IAsyncResult res)
{
WorkCompleted wc = (WorkCompleted)res.AsyncState;
int grade = wc.EndInvoke(res);
Console.WriteLine("Worker grade= " + grade);
}
public event WorkStarted started ;
public event WorkProgressing progressing;
public event WorkCompleted completed;
}
class Boss
{
public int WorkCompleted()
{
System.Threading.Thread.Sleep(3000);
Console.WriteLine("Better...");
return 6; /* out of 10 */
}
}
class Universe
{
static void WorkerStartedWork()
{
Console.WriteLine("Universe notices worker starting work");
}
static int WorkerCompletedWork()
{
System.Threading.Thread.Sleep(4000);
Console.WriteLine("Universe is pleased with worker's work");
return 7;
}
static void Main()
{
Worker peter = new Worker();
Boss boss = new Boss();
peter.completed += new WorkCompleted(boss.WorkCompleted);
peter.started += new WorkStarted(Universe.WorkerStartedWork);
peter.completed += new WorkCompleted(Universe.WorkerCompletedWork);
peter.DoWork();
Console.WriteLine("Main: worker completed work");
Console.ReadLine();
}
}
/*以下是上段程序输出结果：
Worker: work started
Universe notices worker starting work
Worker: work progressing
Worker: work completed
Main: worker completed work //【译注：异步委托发生了效果，因此这一行先输出啦J】
Better...
Worker grade = 6
Universe pleased with worker's work
Worker grade = 7
*/
事件是引发的，
是同步的，
可以通过事件（本身是被特殊支持的对象）的方法来实现异步。
kuangren 2003-10-02
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多线程不就可以同步罗～
sarcophile 2003-10-02
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再顶一下，没有别的高见了吗？
herakless 2003-09-30
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当然a 和 on_e 就在同一线程了
herakless 2003-09-30
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h的剩余部分要等a返回后才执行,和函数调用差不多，跟踪反汇编就知道了
sarcophile 2003-09-30
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1，
jjcccc说: 一般情况h的剩余部分要等a返回后才执行，---- 就是说是同步
cnhgj(戏子)说: 事件是异步,
我：头大。能不能给个证据先？
2，以下说法是我的理解，对不对？
如果两个线程访问同一个全局变量，一定要加锁。要访问同一个函数，应该是给函数中的以下部分加锁：访问全局变量，静态变量，所在实例的成员变量。因为不同线程使用的是这些变量的同一个内存地址。
而以下部分不用加锁：new分配的，动态局部变量。因为new分配的变量每个线程运行时都有新的分配（c++中变量名称作为指针实际是局部变量），而局部变量在堆栈中，每个线程有自己的堆栈，互不干扰。
3，事件处理函数和触发事件的函数是否在同一线程？比如
a(void)
{
event e;
e();//触发事件
}
on_e(void)//事件处理函数
{}
函数 a 和 on_e 是否在同一线程中？
jjcccc说: 一般情况h的剩余部分要等a返回后才执行，---- 就是说是同步
cnhgj(戏子)说: 事件是异步,
我：头大。能不能给个证据先？
2，以下说法是我的理解，对不对？
如果两个线程访问同一个全局变量，一定要加锁。要访问同一个函数，应该是给函数中的以下部分加锁：访问全局变量，静态变量，所在实例的成员变量。因为不同线程使用的是这些变量的同一个内存地址。
而以下部分不用加锁：new分配的，动态局部变量。因为new分配的变量每个线程运行时都有新的分配（c++中变量名称作为指针实际是局部变量），而局部变量在堆栈中，每个线程有自己的堆栈，互不干扰。
3，事件处理函数和触发事件的函数是否在同一线程？比如
a(void)
{
event e;
e();//触发事件
}
on_e(void)//事件处理函数
{}
函数 a 和 on_e 是否在同一线程中？
Reeezak 2003-09-29
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就是阿
这个就是线程同步的问题阿（不知道应该怎么解释，跟楼主说的已经不一样了）
这个就是线程同步的问题阿（不知道应该怎么解释，跟楼主说的已经不一样了）
9tl 2003-09-29
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如果两个线程分别触发同一个事件,好象其中有一个还是要加锁的！
Reeezak 2003-09-29
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事件用异步
同步用线程
这个解释够明白吧？
^_^
同步用线程
这个解释够明白吧？
^_^
cnhgj 2003-09-29
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事件是异步,要同步可以用线程
xiaha3 2003-09-29
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http://www.csdn.net/develop/article/15/15850.shtm
sarcophile 2003-09-29
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2,换个说法：如果两个线程分别触发同一个事件，那么这个事件的处理函数是不是需要加锁？
sarcophile 2003-09-29
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就是说一般情况下相当于函数调用了？
特殊情况得看你在a中是怎样触发h的????
具体什么意思？
特殊情况得看你在a中是怎样触发h的????
具体什么意思？
jjcccc 2003-09-29
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1.一般情况h的剩余部分要等a返回后才执行，特殊情况得看你在a中是怎样触发h的
