好的,所以我有一个名为 readSensor 的函数,您猜对了。读取传感器。
但传感器通常需要大约 100 毫秒才能响应。所以在 readSensor 函数中,我基本上只是启动一个计时器。
在定时事件中,我读取串行端口并得到响应。
但是,这意味着当我希望它在 readSensor 函数中时,我的响应在 onTimedEvent 中。
基本上从我希望能够做到这一点的主要形式。
值 = 读取传感器()
此刻我所能做的就是 readSensor() ,然后一旦 timedEvent 触发,我可以通过在消息框中显示响应来查看响应。
这是我的代码。 (我错过了大量的串口设置和东西,但希望你能看到我遇到的问题)
我不想只是在函数中等待 100 毫秒,尽管轮询计时器,因为这会使我的程序变慢..
我想以某种方式将响应返回给 readSensor 函数,然后返回到表单。
using System;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO.Ports;
using System.Timers;
namespace readSensor
{
public partial class readSens : UserControl
{
public readSens()
{
InitializeComponent();
}
private System.Timers.Timer rTimer;
SerialPort sp = new SerialPort();
private void setupTimer()
{
// Create a timer with a 100ms response.
rTimer = new System.Timers.Timer(100);
rTimer.SynchronizingObject = this;
// Hook up the Elapsed event for the timer.
rTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
}
private void OnTimedEvent(object source, ElapsedEventArgs e)
{
string response = getResponse();
}
public string getResponse()
{
string status = "";
byte[] readBuffer = new byte[255];
if (sp.IsOpen)
{
if (sp.BytesToRead > 0) //there is data to read
{
int length = sp.BytesToRead;
for (int i = 0; i < length; i++)
{
readBuffer[i] = (byte)sp.ReadByte();
status = "pass";
return status;
}
}
}
public void readSensor(byte addr)
{
if (!sp.IsOpen)
{
openPort();
readSensor(addr); // calls itself again once port is opened
}
else if (sp.IsOpen)
{
rTimer.Start();
}
else
{
MessageBox.Show("Port not opened yet");
}
}
}
}
在主要形式中,我基本上只是说
setupTimer();
readSensor();
单击按钮。
最佳答案
启动一个单独的线程,然后从该线程将结果写入主线程中的队列。
class Game1
{
//We declare a queue, which is like an array that we can extract and enter data easily in a FIFO (first in, first out) style list.
Queue<string> q = new Queue<string>();
public void threadStart(object obj)
{
//We get the result of your function, while our main function is still looping and waiting.
string result = readInput()
//We tell C# that the parameter we passed in, is in fact the Game1 class passed from "t.Start"
Game1 game = (Game1)obj;
//This puts our "result" into the queue.
game.q.Enqueue(result);
}
public void start()
{
//Declares a new thread, which will run "threadStart" function.
System.Threading.Thread t = new System.Threading.Thread(threadStart);
//We start the other thread (that will run in parallel) and pass "this" as the parameter.
t.Start(this);
//We loop over and over, sleeping, whilst the other function runs at the same time. This is called "multi- threading"
while (q.Count == 0)
{
System.Threading.Thread.Sleep(10);
}
//This gets the last-entered (oldest) value from the queue q.
string result = q.Deque();
}
}
所以这会启动一个线程来获取结果,然后在我的版本中,轮询队列一段时间直到结果回来,但在你的情况下可以做很多事情,只要你不时检查队列对于新数据。
编辑:添加评论以希望减轻您的一些问题。
关于c# - 如何从定时事件恢复功能,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/17566683/