I decided to create a basic timer just for my use and everytime i click the start button the program freezes up completely. Im i missing something obvious or?
namespace Timer
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btn_Start_Click(object sender, EventArgs e)
{
int secs = 0, mins = 0, hours = 0;
for (int num1 = 1; num1 > 0;)
{
txt_secs.Text = secs.ToString() ;
System.Threading.Thread.Sleep(1000);
secs = secs + 1;
if (secs == 60)
{
secs = 0;
mins = mins + 1;
txt_mins.Text = mins.ToString();
}
if (mins == 60)
{
mins = 0;
hours = hours + 1;
txt_hours.Text = hours.ToString();
}
}
}
}
}
The issue is in System.Threading.Sleep()
Per Microsoft Documentation your thread will be suspended. The thread is in an infinite loop and thus will be (essentially) permanently suspended.
Consider using Timers or the Stopwatch Class or (if you need threading) System.Threading.Timer Instead
Related
I have .Net framwork 4.7.2 application, which handles cpu-intensive workload.
It uses system.timers.timer, intend to force program timeout after x mins.
The timer sometimes is not able to trigger on time.
Any suggestion on making the timer work properly, without loosing workload efficiency?
Following is the code to demonstrate the issue.
The timer set to triggered every 5 secs, but result is not as expected, which is shown in screenshot.
Please note that size of taskCollection is not predictable.
class Program
{
static void Main(string[] args)
{
var taskCollection = new string[new Random().Next(10, 100)];
SetupTimer();
Parallel.ForEach(taskCollection
, new ParallelOptions { MaxDegreeOfParallelism = -1 }
, task =>
{
SlowTask();
}
);
}
static void SetupTimer()
{
System.Timers.Timer aTimer = new System.Timers.Timer();
aTimer.Elapsed += (s_, e_) =>
{
OnTimedEvent(s_, e_);
};
aTimer.Interval = 5000;
aTimer.Enabled = true;
Console.WriteLine($"Timer has been started at {DateTime.Now}.");
}
static void OnTimedEvent(object source, ElapsedEventArgs e)
{
Console.WriteLine($"Timer has been triggered at {DateTime.Now}.");
}
static void SlowTask()
{
long nthPrime = FindPrimeNumber(10000000); //set higher value for more time
}
static long FindPrimeNumber(int n)
{
int count = 0;
long a = 2;
while (count < n)
{
long b = 2;
int prime = 1;
while (b * b <= a)
{
if (a % b == 0)
{
prime = 0;
break;
}
b++;
}
if (prime > 0)
{
count++;
}
a++;
}
return (--a);
}
}
In my program I'm trying to see how long it will take to calculate an amount of prime numbers
double time;
private void button1_Click(object sender, EventArgs e)
{
bool isPrime = true;
timer1.Start();
for (int i = 2; i <= 200000; i++)
{
for (int j = 2; j <= 200000; j++)
{
if (i != j && i % j == 0)
{
isPrime = false;
break;
}
}
if (isPrime)
{
//listBox1.Items.Add(i);
}
isPrime = true;
}
timer1.Stop();
MessageBox.Show(time.ToString() + "ms");
}
private void timer1_Tick(object sender, EventArgs e)
{
time += 0.001; ;
}
However when the program finishes calculating the messagebox displays time as zero.
I tested the program using the stopwatch class and that works, however I was wondering is there any way to use a timer instead?
Thank you!
If this is purely academic:
myTimer.Interval = 1;
myTimer.Elapsed += IncrementEvent;
You could do the above to fire an event on each increment.
Causing the event to be fired every ~1ms.
public int incrementCounter {get; set; }
public void IncrementEvent()
{
incrementCounter++;
}
I also believe you'd need to wire this up for multi-threading. (I can't remember the last time I used a timer, and never in a tight loop where locking would be a concern.
and then obviously use that value in your message box:
MessageBox.Show(incrementCounter.ToString() + "ms");
However, I'd argue to never use anything like this in production.
You don't have much precision. 1ms is the smallest unit of time.
The timer isn't very reliable. Even running it every few seconds, you'll see milliseconds of the time executed vary slightly.
A timer is meant to schedule events to happen once t(ime) has ellapsed. There are much better tools for measuring how long an event takes.
I don't know how to explain this clearly but I will try my best.
I'm using a DispatcherTimer class in my windows phone 8 project. I've got some check boxes and when a check box is checked and the button is pressed the countdown from a bus schedule starts. Everything works perfectly here but when I uncheck the check box and when I check another one, the same bus time starts and it goes down(countdown) by 2 seconds now. If I uncheck the check box and check another again the same time starts to countdown and the countdown goes by 3 seconds... I don't understand how, because on the click_event there is always a new instance of the class.
The only thing that solves the problem is to reload my wp8 page and check something again and press the button for the countdown to start.
Note: I'm reading my times from a .txt file which are store on a folder within my project (using streamreader).
Any suggestions?
Here is some code:
CheckBox[] listchekbox;
DispatcherTimer timer;
private void Button_Click(object sender, RoutedEventArgs e)//BUTTON CLICK
{
timer = new DispatcherTimer();
listchekbox = new CheckBox[4] { Check1, Check2, Check3, Check4 };
if (Onlyoneclick(listchekbox, 0)) { Gettingbustime(path_names[0]); }
else if (Onlyoneclick(listchekbox, 1)) { Gettingbustime(path_names[1]); }
timer.Interval = new TimeSpan(0,0,1);
timer.Tick += onclick;
timer.Start();
}
private void onclick(object sender, EventArgs e) // TIMER EVENT COUNT
{
Countdown(bus1); // the parameter is the textbox where the result is displayed
Countdown(bus2);
}
private bool Onlyoneclick(CheckBox[] itemselected,int id) // this is not so important
{
int itemcounter = 0;
int falsecounter = 0;
for (int i = 0; i < listchekbox.Length; i++)
{
if (itemselected[i].IsChecked == true && id == i)
{
itemcounter++;
}
else if (itemselected[i].IsChecked == true) { falsecounter++; }
}
if (itemcounter == 1 && falsecounter==0) { return true; }
else { return false; }
}
public void Countdown(TextBlock tx)
{
string minute = tx.Text.Substring(0, 2);
string sekunde = tx.Text.Substring(3, 2);
int minute1 = Convert.ToInt32(minute);
int sekunde1 = Convert.ToInt32(sekunde);
sekunde1 = sekunde1 - 1;
if (sekunde1 < 0)
{
minute1 = minute1 - 1;
sekunde1 = 59;
}
if (minute1 < 0)
{
timer.Stop();
MessageBox.Show("Autobus left!");
}
if (sekunde1 < 10) { tx.Text = minute1.ToString() + ":0" + sekunde1.ToString(); }
else { tx.Text = minute1.ToString() + ":" + sekunde1.ToString(); }
if (minute1 < 10) { tx.Text = "0" + minute1.ToString() + ":" + sekunde1.ToString(); }
if (minute1 < 10 && sekunde1 < 10) { tx.Text = "0" + minute1.ToString() + ":0" + sekunde1.ToString(); }
}
Try removing this code from Button_Click:
timer = new DispatcherTimer();
timer.Interval = new TimeSpan(0,0,1);
timer.Tick += onclick;
And add it instead to your constructor.
In the top of form1 i have:
private int seconds;
private int minutes;
private int hours;
In the constructor:
seconds = 0;
minutes = 20;
hours = 0;
label9.Visible = false;
label9.Text = "00:00:00";
Then the timer 3 tick event. I used a breakpoint on the timer3 tick event i see that the minutes and seconds are coundting backwards but label 9 is not updating.
Maybe the string.Format on label9 is not right ?
private void timer3_Tick(object sender, EventArgs e)
{
// Verify if the time didn't pass.
if ((minutes == 0) && (hours == 0) && (seconds == 0))
{
// If the time is over, clear all settings and fields.
// Also, show the message, notifying that the time is over.
timer3.Enabled = false;
label9.Visible = true;
label9.Text = "00:00:00";
}
else
{
// Else continue counting.
if (seconds < 1)
{
seconds = 59;
if (minutes == 0)
{
minutes = 59;
if (hours != 0)
hours -= 1;
}
else
{
minutes -= 1;
}
}
else
seconds -= 1;
// Display the current values of hours, minutes and seconds in
// the corresponding fields.
label7.Visible = true;
label9.Visible = true;
label9.Text = string.Format("{00} : {00} : {00}", hours.ToString(), minutes.ToString(),seconds.ToString());
}
}
All i see in the end on label 9 is: 0:0:0 thats it and i dont see 20 minutes counting backward.
You need to fix your string formatting, that's the culprit:
label9.Text = string.Format("{0:00} : {1:00} : {2:00}", hours, minutes, seconds);
Also - consider using some other mechanism (e.g. Stopwatch class) for calculating elapsed time; you can't guarantee that the code as written will execute exactly every 1000 ms.
I am writing a WinForm application to use SNMP calls either every 30 seconds or 1 minute.
I have a timer working for calling my SNMP commands, but I want to add a texbox counter that display the total time elapsed during the operation.
There are many problems I am having so here is a list:
I want my SNMP timer 'timer' to execute once before waiting the allotted time so I have it going off at 3 seconds and then changing the interval in my handler. But this sometimes makes the timer go off multiple times which is not what I want.
Every time 'timer' goes off and my SNMP calls execute my counter timer 'appTimer' becomes out of sync. I tried a work around where I check if it is in the other handler and then just jump the timer to its appropriate time. Which works but I feel this is making it too complicated.
My last issue, that I know of, happens when I stop my application using my stop button which does not completely exit the app. When I go to start another run the time between both timers is becomes even greater and for some reason my counting timer 'appTimer' starts counting twice as fast.
I hope this description isn't too confusing but here is my code anyway:
using System;
using System.Net;
using SnmpSharpNet;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public static bool stop = false;
static bool min = true, eye = false, firstTick = false;
static string ipAdd = "", fileSaveLocation = "";
static System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();
static System.Windows.Forms.Timer appTimer = new System.Windows.Forms.Timer();
static int alarmCounter = 1, hours = 0, minutes = 0, seconds = 0, tenthseconds = 0, count = 0;
static bool inSNMP = false;
static TextBox textbox, timeTextbox;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
textbox = outputBox;
timeTextbox = timeBox;
ipAdd = "192.168.98.107";
fileSaveLocation = "c:/Users/bshellnut/Desktop/Eye.txt";
min = true;
inSNMP = false;
}
private void IPtext_TextChanged(object sender, EventArgs e)
{
ipAdd = IPtext.Text;
}
private void stopButton_Click(object sender, EventArgs e)
{
stop = true;
timer.Stop();
appTimer.Stop();
count = 0;
hours = minutes = seconds = tenthseconds = 0;
inSNMP = false;
}
// This is the method to run when the timer is raised.
private static void TimerEventProcessor(Object myObject,
EventArgs myEventArgs)
{
inSNMP = true;
timer.Stop();
if (firstTick == true)
{
// Sets the timer interval to 60 seconds or 1 second.
if (min == true)
{
timer.Interval = 1000 * 60;
}
else
{
timer.Interval = 1000 * 30;
}
}
// Displays a message box asking whether to continue running the timer.
if (stop == false)
{
textbox.Clear();
// Restarts the timer and increments the counter.
alarmCounter += 1;
timer.Enabled = true;
System.IO.StreamWriter file;
//if (eye == true)
//{
file = new System.IO.StreamWriter(fileSaveLocation, true);
/*}
else
{
file = new System.IO.StreamWriter(fileSaveLocation, true);
}*/
// SNMP community name
OctetString community = new OctetString("public");
// Define agent parameters class
AgentParameters param = new AgentParameters(community);
// Set SNMP version to 2 (GET-BULK only works with SNMP ver 2 and 3)
param.Version = SnmpVersion.Ver2;
// Construct the agent address object
// IpAddress class is easy to use here because
// it will try to resolve constructor parameter if it doesn't
// parse to an IP address
IpAddress agent = new IpAddress(ipAdd);
// Construct target
UdpTarget target = new UdpTarget((IPAddress)agent, 161, 2000, 1);
// Define Oid that is the root of the MIB
// tree you wish to retrieve
Oid rootOid;
if (eye == true)
{
rootOid = new Oid("1.3.6.1.4.1.128.5.2.10.14"); // ifDescr
}
else
{
rootOid = new Oid("1.3.6.1.4.1.128.5.2.10.15");
}
// This Oid represents last Oid returned by
// the SNMP agent
Oid lastOid = (Oid)rootOid.Clone();
// Pdu class used for all requests
Pdu pdu = new Pdu(PduType.GetBulk);
// In this example, set NonRepeaters value to 0
pdu.NonRepeaters = 0;
// MaxRepetitions tells the agent how many Oid/Value pairs to return
// in the response.
pdu.MaxRepetitions = 5;
// Loop through results
while (lastOid != null)
{
// When Pdu class is first constructed, RequestId is set to 0
// and during encoding id will be set to the random value
// for subsequent requests, id will be set to a value that
// needs to be incremented to have unique request ids for each
// packet
if (pdu.RequestId != 0)
{
pdu.RequestId += 1;
}
// Clear Oids from the Pdu class.
pdu.VbList.Clear();
// Initialize request PDU with the last retrieved Oid
pdu.VbList.Add(lastOid);
// Make SNMP request
SnmpV2Packet result;
try
{
result = (SnmpV2Packet)target.Request(pdu, param);
}
catch (SnmpSharpNet.SnmpException)
{
timer.Stop();
textbox.Text = "Could not connect to the IP Provided.";
break;
}
// You should catch exceptions in the Request if using in real application.
// If result is null then agent didn't reply or we couldn't parse the reply.
if (result != null)
{
// ErrorStatus other then 0 is an error returned by
// the Agent - see SnmpConstants for error definitions
if (result.Pdu.ErrorStatus != 0)
{
// agent reported an error with the request
textbox.Text = "Error in SNMP reply. " + "Error " + result.Pdu.ErrorStatus + " index " + result.Pdu.ErrorIndex;
lastOid = null;
break;
}
else
{
// Walk through returned variable bindings
foreach (Vb v in result.Pdu.VbList)
{
// Check that retrieved Oid is "child" of the root OID
if (rootOid.IsRootOf(v.Oid))
{
count++;
textbox.Text += "#" + count + " " + v.Oid.ToString() + " " + SnmpConstants.GetTypeName(v.Value.Type) +
" " + v.Value.ToString() + Environment.NewLine;
file.WriteLine("#" + count + ", " + v.Oid.ToString() + ", " + SnmpConstants.GetTypeName(v.Value.Type) +
", " + v.Value.ToString(), true);
if (v.Value.Type == SnmpConstants.SMI_ENDOFMIBVIEW)
lastOid = null;
else
lastOid = v.Oid;
}
else
{
// we have reached the end of the requested
// MIB tree. Set lastOid to null and exit loop
lastOid = null;
}
}
}
}
else
{
//Console.WriteLine("No response received from SNMP agent.");
textbox.Text = "No response received from SNMP agent.";
//outputBox.Text = "No response received from SNMP agent.";
}
}
target.Close();
file.Close();
}
else
{
// Stops the timer.
//exitFlag = true;
count = 0;
}
}
private static void ApplicationTimerEventProcessor(Object myObject,
EventArgs myEventArgs)
{
tenthseconds += 1;
if (tenthseconds == 10)
{
seconds += 1;
tenthseconds = 0;
}
if (inSNMP && !firstTick)
{
if (min)
{
seconds = 60;
}
else
{
textbox.Text += "IN 30 SECONDS!!!";
if (seconds < 30)
{
seconds = 30;
}
else
{
seconds = 60;
}
}
}
if(seconds == 60)
{
seconds = 0;
minutes += 1;
}
if(minutes == 60)
{
minutes = 0;
hours += 1;
}
timeTextbox.Text = (hours < 10 ? "00" + hours.ToString() : hours.ToString()) + ":" +
(minutes < 10 ? "0" + minutes.ToString() : minutes.ToString()) + ":" +
(seconds < 10 ? "0" + seconds.ToString() : seconds.ToString()) + "." +
(tenthseconds < 10 ? "0" + tenthseconds.ToString() : tenthseconds.ToString());
inSNMP = false;
firstTick = false;
}
private void eyeButton_Click(object sender, EventArgs e)
{
outputBox.Text = "Connecting...";
eye = true;
stop = false;
count = 0;
hours = minutes = seconds = tenthseconds = 0;
timer.Tick += new EventHandler(TimerEventProcessor);
timer.Interval = 3000;
firstTick = true;
appTimer.Tick += new EventHandler(ApplicationTimerEventProcessor);
appTimer.Interval = 100;
appTimer.Start();
timer.Start();
}
private void jitterButton_Click(object sender, EventArgs e)
{
outputBox.Text = "Connecting...";
eye = false;
stop = false;
count = 0;
hours = minutes = seconds = tenthseconds = 0;
timer.Tick += new EventHandler(TimerEventProcessor);
timer.Interval = 3000;
firstTick = true;
appTimer.Tick += new EventHandler(ApplicationTimerEventProcessor);
appTimer.Interval = 100;
appTimer.Start();
timer.Start();
}
private void Seconds_CheckedChanged(object sender, EventArgs e)
{
min = false;
}
private void Minutes_CheckedChanged(object sender, EventArgs e)
{
min = true;
}
private void exitButton_Click(object sender, EventArgs e)
{
Application.Exit();
}
private void savetextBox_TextChanged(object sender, EventArgs e)
{
fileSaveLocation = savetextBox.Text;
}
}
}
This is very easy to do with a single timer. The timer has a 1/10th second resolution (or so) and can be used directly to update the elapsed time. You can then use relative elapsed time within that timer to fire off your SNMP transaction, and you can reschedule the next one dynamically.
Here's a simple example
using System;
using System.Drawing;
using System.Windows.Forms;
class Form1 : Form
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
DateTime lastSnmpTime;
TimeSpan snmpTime = TimeSpan.FromSeconds(30);
DateTime startTime;
TextBox elapsedTimeTextBox;
Timer timer;
public Form1()
{
timer = new Timer { Enabled = false, Interval = 10 };
timer.Tick += new EventHandler(timer_Tick);
elapsedTimeTextBox = new TextBox { Location = new Point(10, 10), ReadOnly = true };
Controls.Add(elapsedTimeTextBox);
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
startTime = DateTime.Now;
timer.Start();
}
void timer_Tick(object sender, EventArgs e)
{
// Update elapsed time
elapsedTimeTextBox.Text = (DateTime.Now - startTime).ToString("g");
// Send SNMP
if (DateTime.Now - lastSnmpTime >= snmpTime)
{
lastSnmpTime = DateTime.Now;
// Do SNMP
// Adjust snmpTime as needed
}
}
}
Updated Q&A
With this code the timer fires once at the beginning where after I
press the stop button and call timer.Stop() and then press my start
button the timer doesn't fire until roughly 12 seconds later. Will
resetting the DateTimes fix this?
When the user presses the Start button, set lastSnmpTime = DateTime.MinValue. This causes the TimeSpan of (DateTime.Now - lastSnmpTime) to be over 2,000 years, so it will be greater than snmpTime and will fire immediately.
Also my output time in the text box looks like this: 0:00:02.620262.
Why is that? Is there a way to make it display only 0:00:02.62?
When you subtract two DateTime values, the result is a TimeSpan value. I used a standard TimeSpan formatting string of "g". You can use a custom TimeSpan formatting string of #"d\:hh\:mm\:ss\.ff" to get days:hours:minutes:seconds.fraction (2 decimal places).
Also will the timer go on and print out to the text box when it is run
for over 9 hours? Because I plan to have this running for 24 hrs+
If you use the custom format with 'd' to show the number of days, it will run for TimeSpan.MaxValue which is slightly more than 10,675,199 days, which is more than 29,000 years.