问题描述
我不得不问,因为我找不到与 UI BeginInvoke 异步完成相同的方式。
我在 Winforms 上运行的示例程序和所有委托方法都在主 UI 线程中调用。我记录了状态,发现它在不同的 BeginInvoke
上的同一线程上运行。
从 Winforms UI 登录:
13/01/2021 11:57:23 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: False,Thread Pool: False,Thread ID: 1
13/01/2021 11:57:23 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: False,Thread ID: 1
13/01/2021 11:57:23 [SendNextCommand] - [SendNextCommand] Background: False,Thread ID: 1
13/01/2021 11:57:24 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: False,Thread ID: 1
13/01/2021 11:57:24 [SendNextCommand] - [SendNextCommand] Background: False,Thread ID: 1
我想将其转换为类库,以便为我的实际应用程序集成为 DLL。但是我找不到如何让 fnCmdInProgressAction
和 SendNextCommand
方法在同一个线程中运行。因为,我有一个链式命令,它需要排队,因为对象值将被清除并允许下一个命令执行到串口。
从我的类库登录:
13/01/2021 11:30:51 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: True,Thread Pool: True,Thread ID: 6
13/01/2021 11:30:52 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: True,Thread ID: 9
13/01/2021 11:30:55 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: True,Thread ID: 7
13/01/2021 11:30:55 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: True,Thread ID: 6
13/01/2021 11:30:56 [SendNextCommand] - [SendNextCommand] Background: True,Thread ID: 7
13/01/2021 11:30:56 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: True,Thread ID: 9
13/01/2021 11:30:57 [fnCmdInProgressAction] - [fnCmdInProgressAction] Background: True,Thread ID: 7
13/01/2021 11:30:58 [SendNextCommand] - [SendNextCommand] Background: True,Thread ID: 6
我尝试过 ThreadPool、Delegate.BeginInvoke、Thread Task。但仍然导致不同的线程。以下是我尝试过的示例:
private delegate void CmdInProgressAction(bool state,Tools.CommandReply cr);
private void fnCmdInProgressAction(object param)
{
if (cr != null)
{
m_CmdInProgress = cr;
//.......
}
m_CmdInProgress = null;
}
// Code from Winform UI BeginInvoke
private void SetCmdInProgress(bool state,CommandReply cr)
{
CmdInProgressAction fn = null;
object[] param = new object[] { state,cr };
fn = new CmdInProgressAction(fnCmdInProgressAction);
BeginInvoke(fn,param);
}
// My try
private void SetCmdInProgress(bool state,CommandReply cr)
{
//========================= TRY 1 =================================================
new Task(() => { fnCmdInProgressAction(state,cr); }).Start();
//========================= TRY 2 =================================================
CmdInProgressAction fn = fnCmdInProgressAction;
fn.BeginInvoke(state,cr,null,null);
//========================= TRY 3 =================================================
new Thread(new ThreadStart(() => fnCmdInProgressAction(state,cr))).Start();
//========================= TRY 4 =================================================
ThreadPool.QueueUserWorkItem(fnCmdInProgressAction,new object[] { state,cr });
}
public void SendNextCommand(TXNextCommand tnxc)
{
Thread thread = Thread.CurrentThread;
string message = $"[SendNextCommand] Background: {thread.IsBackground},Thread Pool: {thread.IsThreadPoolThread},Thread ID: {thread.ManagedThreadId}";
WriteLog.ProcessLog(message);
if (m_CmdInProgress == null)
{
m_CmdInProgress = tnxc.mcr;
serial.SendCommand(m_CmdInProgress);
}
}
private string HandleReply(bool GoodResult,Tools.CommandReply cr)
{
int nextChannel = cr.m_tag + 1;
TXNextCommand tnxc= new TXNextCommand(new TXReadCassetteDeno($"Read Cassette {nextChannel} Deno","RV-1X2",5,channel: nextChannel));
tnxc.mcr.SetReplyHandlerDelegate(HandleReply);
/// Below is code from Winforms UI Async on main thread
dSendNextCommand fn = new dSendNextCommand(SendNextCommand);
object[] param = new object[] { nctt };
BeginInvoke(fn,param);
}
在同一线程中从 HandleReply
和 fnCmdInProgressAction
运行委托的正确方法是什么,例如 SendNextCommand
调用,m_CmdInProgress
已经为空,因此它可以发送下一个命令。 Winforms UI 没有问题,因为它就像在同一线程上排队调用。我如何将它应用于类库,因为我尝试过的无法实现我想要的。我已经阅读了任务异步编程,TPL。我不能使用异步,因为它会弄乱串行类对象上的委托。
解决方法
回答我的问题。根据 Peter Csala 的推荐,我正在使用 ConcurrentExclusiveSchedulerPair
。现在命令可以根据需要执行。这是我所做的。
static ConcurrentExclusiveSchedulerPair taskSchedulerPair = new ConcurrentExclusiveSchedulerPair();
TaskFactory exclusiveTaskFactory = new TaskFactory(taskSchedulerPair.ExclusiveScheduler);
private void SetCmdInProgress(bool state,Tools.CommandReply cr)
{
//====================================================================================
exclusiveTaskFactory.StartNew(() => { fnCmdInProgressAction(new object[] { state,cr }); });
//====================================================================================
}
private string HandleReply(bool GoodResult,Tools.CommandReply cr)
{
int nextChannel = cr.m_tag + 1;
TXCommand.TXNextCommand tnxc = new TXCommand.TXNextCommand(new TXCommand.TXReadCassetteDeno($"Read Cassette {nextChannel} Deno","RD/9X27",5,channel: nextChannel));
tnxc.mcr.SetReplyHandlerDelegate(HandleReply);
//====================================================================================
exclusiveTaskFactory.StartNew(() => { SendNextCommand(new object[] { tnxc }); });
//====================================================================================
}
我仍然得到了一些不同的线程 id;但是,通过使用 ConcurrentExclusiveSchedulerPair
,它可以将任务排入队列,然后根据需要的流程继续执行另一个任务