Develop Reference

Visual Studio C# using timer to hold down the program for 1 hour

I am a new user and i wish to add a timer to hold down the program for an hour and then continues.
This is the procedure:
Issue a command through serialport e.g. high
Holds for an hour
Issue again the same command 'high'
Holds for an hour
It repeats until a button is pressed.
How should i implement the timer? Because i tried searching online and found some examples.
I included this in Form1.cs:
static System.Timers.Timer Timer1;
void button1_Click(object sender, EventArgs e)
{
Timer1 = new System.Timers.Timer(60*60*1000);
Timer1.Elapsed += new ElapsedEventHandler(TimedEvent);
Timer1.Enabled = true;
}
private void TimedEvent(Object source, ElapsedEventArgs e)
{
serialPort1.Write("high");
}
Even though this code helps to repeat the high every hour but it only does the TimedEvent after 60 minutes. I need to write into the serialport first then execute the timer. How do i amend the codes to achieve the result i want?
Edited:
I realised that this code does not work as in the timer did not hold for an hour. Instead place it in form1_load to work.
private void Form1_Load(object sender, EventArgs e)
{
Timer1 = new System.Timers.Timer(10*1000);
Timer1.Elapsed += TimedEvent;
}
Tried this (below) but the timer didn't work
static System.Windows.Forms.Timer timer4 = new System.Windows.Forms.Timer();
void button1_Click(object sender, EventArgs e)
{
Writetoserialport();
timer4.Interval = 10000; // testing on 10second interval
timer4.Enabled = true;
}
When i remove Writetoserialport() , the program runs forever.

Call TimedEvent directly for the first run:
private void Form1_Load(object sender, EventArgs e)
{
Timer1 = new System.Timers.Timer(10*1000);
Timer1.Elapsed += TimedEvent;
TimedEvent();
}
But for something that happens as rare as hourly, a Windows Service might be a better option.

This will work but will probably crash when you close the program sometimes because System.Timers.Timer triggers the TimedEvent on a ThreadPool thread. What will probably happen sometimes is when your program is closed, the SerialPort object will be disposed, but since the Timer is still executing on on another thread it will trigger the TimedEvent and try and write to the serialPort but it will crash the program because it will have been disposed.
You should look at System.Windows.Forms.Timer which is meant for using with GUI threads like this.
// INSTEAD, TRY THIS.
// It's really late here forgot to change some code after copy pasting from
above, should be good now.
static System.Windows.Forms.Timer timer1;
void button1_Click(object sender, EventArgs e)
{
timer1 = new System.Windows.Forms.Timer(60*60*1000);
timer1.Tick += Timer1_Tick;
timer1.Enabled = true;
WriteToSerialPort(); // Call method directly for writing to port.
}
private void timer1_Tick(object sender, EventArgs e)
{
WriteToSerialPort();
}
private void WriteToSerialPort()
{
serialPort1.Write("high"); // write to port
}

Here is another example that allows you to not have a dedicated method for writing to the serial port. I would want the dedicated method so the serial port could be written to outside of the timer tick event without having to write the serial port code more than once. The code below needs to be in try...catch blocks. Note: System.Windows.Forms.Timer here.
using System;
using System.Drawing;
using System.IO.Ports;
using System.Windows.Forms;
namespace SerialPortSample
{
public partial class Form1 : Form
{
private Timer timer1 = new Timer { Interval = 1000, Enabled = false }; // initialize timer, with a one second interval and disabled
private Button startTimerButton = new Button { Name = "startTimerButton",Text = #"Toggle Timer", Size = new Size(130, 33), Location = new Point(0, 0) };
// This is a place holder for the SerialPort control you probably have on your Form.
//Remove this instance of serialPort1 and use the serialPort1 control from your form.
private SerialPort serialPort1 = new SerialPort();
public Form1()
{
InitializeComponent();
// add button to Form
this.Controls.Add(startTimerButton); // add button to form1
startTimerButton.Click += StartTimerButton_Click;
timer1.Tick += Timer1_Tick; // attach timer tick event
}
private void StartTimerButton_Click(object sender, EventArgs e)
{
timer1.Enabled = !timer1.Enabled; // toggle timer.endabled, if false the Tick event will not be raised
timer1.Interval = 1000; // set timer interval to 1000 so the next time it is enabled it triggers immediately.
}
private void Timer1_Tick(object sender, EventArgs e)
{
timer1.Interval = 60 * 60 * 1000; // set timer interval to 1 hour so it will not trigger for an hour
if (!serialPort1.IsOpen)
serialPort1.Open(); // open serial port if not open
serialPort1.Write("high"); // write to the serial port
serialPort1.Close(); // close serial port
}
}
}

When CheckBox is unchecked make it unable for specific time C#

I am working on antivirus program and on real-time protection panel I want checkbox when for example "Malware protection" checkbox is unchecked to make it not enable for like 15 minutes and after that time it is enabled again so it prevents spam.
If somebody can help me it would be great
I tried with Thread.Sleep() but it stops whole application, and I tried with timer but I think I did it wrong.
This is code for timer
private void checkBox1_CheckStateChanged(object sender, EventArgs e)
{
if (this.checkBox1.Checked)
{
this.checkBox1.Text = "On";
// these two pictureboxes are for "You are (not) protected"
// picture
picturebox1.Show();
pictureBox5.Hide();
timer1.Stop();
}
else
{
this.checkBox1.Text = "Off";
// this is the problem
timer1.Start();
this.checkBox1.Enabled = true;
pictureBox1.Hide();
pictureBox5.Show();
}
}
private void timer1_Tick(object sender, EventArgs e)
{
this.checkBox1.Enabled = false;
}

Short Answer
From the code you posted, it really only appears that you need to change the code to disable the checkbox in the CheckChanged event and enable it in the timer1_Tick event (and also Stop the timer in the Tick event).
Full Answer
Winforms has a Timer control that you can use for this. After you drop a Timer onto the designer, set the Interval property to the number of milliseconds you want to wait before enabling the checkbox (1 second is 1000 milliseconds, so 15 minutes is 15min * 60sec/min * 1000ms/sec, or 900,000 ms). Then double-click it to create the Tick event handler (or add one in your Form_Load event as I've done below).
Next, in the CheckChanged event, if the checkbox is not checked, disable the checkbox and start the timer.
Then, in the Tick event, simply enable the checkbox (remember, this event is triggered after Interval milliseconds have passed) and stop the timer.
For example:
private void Form1_Load(object sender, EventArgs e)
{
// These could also be done in through designer & property window instead
timer1.Tick += timer1_Tick; // Hook up the Tick event
timer1.Interval = (int) TimeSpan.FromMinutes(15).TotalMilliseconds; // Set the Interval
}
private void timer1_Tick(object sender, EventArgs e)
{
// When the Interval amount of time has elapsed, enable the checkbox and stop the timer
checkBox1.Enabled = true;
timer1.Stop();
}
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
if (!checkBox1.Checked)
{
// When the checkbox is unchecked, disable it and start the timer
checkBox1.Enabled = false;
timer1.Start();
}
}

This can be done without using Timer explicitly. Instead use asynchronous Task.Delay, which will simplify the code and make it easy to understand actual/domain intentions.
// Create extension method for better readability
public class ControlExtensions
{
public static Task DisableForSeconds(int seconds)
{
control.Enabled = false;
await Task.Delay(seconds * 1000);
control.Enabled = true;
}
}
private void checkBox1_CheckStateChanged(object sender, EventArgs e)
{
var checkbox = (CheckBox)sender;
if (checkbox.Checked)
{
checkbox.Text = "On";
picturebox1.Show();
pictureBox5.Hide();
}
else
{
checkbox.Text = "Off";
checkbox.DisableForSeconds(15 * 60);
pictureBox1.Hide();
pictureBox5.Show();
}
}

You could diseable and enable it with task.Delay(). ContinueWith(). This creates a new thread that fires after the delay is done. You need to make it thread safe, winforms isnt thread safe on its own

You should use Timer.SynchronizationObject

Checking for a non typing interval

This question is a bit obscure, however I cannot find an answer for it anywhere. I am writing a program in C# (Visual Studio Pro 2013) and I need to perform an action after the user has stopped typing for 2 seconds (setting the interval at 2000). I would need a standard timer for this however I need to detect when the user has stopped typing for 2 seconds. How would I go about doing this?

Here's the complete code:
public partial class Form1 : Form
{
System.Timers.Timer timer;
public Form1()
{
InitializeComponent();
// Initialize the timer.
timer = new System.Timers.Timer();
timer.Interval = 2000; // = 2 seconds; 1 second = 1000 miliseconds
timer.Elapsed += OnElapsed;
}
// Handles the TextBox.KeyUp event.
// The event handler was added in the designer via the Properties > Events > KeyUp
private void textBox1_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
{
// Reset the timer on each KeyUp.
timer.Stop();
timer.Start();
}
private void OnElapsed(object source, ElapsedEventArgs e)
{
// When time's up...
// - stop the timer first...
timer.Stop();
// - do something more...
MessageBox.Show("Time out!");
}
}

king.code's answer would be correct if you just reset the timer in the first line of textBox1_KeyUp event and initialize the timer in constructor or main method depending on usage.
System.Timers.Timer timer;
private void textBox1_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
{
timer.Stop();
timer.Start();
timer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
}
private static void OnTimedEvent(object source, ElapsedEventArgs e)
{
// Do something
}
I would recommend you go for class that inherits text box and pass timer into it if you are going to use it at multiple places

Try this:
System.Timers.Timer timer = new System.Timers.Timer(2000);;
timer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
timer.Enabled = false;
private void textBox1_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
{
timer.Enabled = false;
timer.Enabled = true;
}
private static void OnTimedEvent(object source, ElapsedEventArgs e)
{
// Do something
timer.Enabled = false;
}

That is easy just create a timer that sets to 2000 Ms and handle
It by the text change interveral .
Ex:
Set an integer that count from 0 to 2000 then increase it by the
Timer if user starts typing then reset the number else keep
Counting till reach 2000 an ping do the rusty homeboy helped;)

I have just found a valid answer that is simple and compact. I will explain it first and then show a code example. You need to start the timer disabled, and then you need to enable it as soon as the the user presses a key. Then, while still in the method for the user pressing the button you would need to reset the timer interval back to 2000. Whenever the timer expires, you do the action that needs to happen when the keyboard has been inactive for 2 seconds. Code example:
private void textBox_KeyPress(object sender, KeyPressEventArgs e)
{
this.timer.Enabled = true;
this.timer.Interval = 2000;
}
Now the method for the timer_Tick:
private void timer_Tick(object sender, EventArgs e)
{
//Do something when the keyboard has been inactive in 2 seconds
}

Making a control to be visible only for a particular amount of time in c#

I am developing an application where i need the following requirement:
Suppose i have a button and a label (initially visibility set to false) in my form, and user clicks on the button, then the label should be displayed with some text that i assign to the label in the button click. But this label should be displayed only for some time, say some 3 secs and then it should automatically go invisible. For this if i gave:
private void button1_Click(object sender, EventArgs e)
{
label1.Visible=true;
label1.Text= "Magic";
Thread.Sleep(3000);
label1.Visible=false;
}
This code does not help the purpose. What is the approach to do it?

Try replacing the last two lines of your method with this:
System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();
timer.Interval = 3000;
timer.Tick += (source, e) => {label1.Visible = false; timer.Stop();};
timer.Start();
Using Thread.Sleep() is never a good idea in WinForms; use timers instead.

Create a timer with 3s as Interval, start it, and set Visible to false in your timer Tick event. Also don't forget to stop the timer.
Never call Thread.Sleep in your UI thread: the application will be blocked as the UI thread won't accept messages (user click...) while sleeping.

// create a global _timer object
static Timer _timer; // From System.Timers
private void button1_Click(object sender, EventArgs e)
{
label1.Text = "Magic";
// Thread.Sleep(3000); // don't do Thread.Sleep()!
label1.Visible = false;
Start();
}
static void Start()
{
label1.Visible = true;
_timer = new Timer(3000); // Set up the timer for 3 seconds
_timer.Elapsed += new ElapsedEventHandler(_timer_Elapsed);
_timer.Enabled = true; // Enable it
}
static void _timer_Elapsed(object sender, ElapsedEventArgs e)
{
label1.Visible = false;
_timer.Stop();
}

Use Timer, perhaps Windows.Forms.Timer. You may have to play with enabling and disabling it when needed and not needed. Your current way does not help, coz your making the main UI thread to sleep. No use.

c# loop every minute - where to put the code?

Currently I'm moving from java to c# and I'm full of crazy questions.
I'm trying new things on a windows form application and now,I would like to create a loop wich is executing a code every 1 minute,the problem is that I have no idea where to put this code.
For example,the form structure is like:
using System;
namespace Tray_Icon
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
notifyIcon1.ShowBalloonTip(5000);
}
private void notifyIcon1_BalloonTipClicked(object sender, EventArgs e)
{
label1.Text = "Baloon clicked!";
}
private void notifyIcon1_BalloonTipClosed(object sender, EventArgs e)
{
label1.Text = "baloon closed!";
}
private void contextMenuStrip1_Opening(object sender, CancelEventArgs e)
{
}
private void option1ToolStripMenuItem_Click(object sender, EventArgs e)
{
//some code here
}
private void option2ToolStripMenuItem_Click(object sender, EventArgs e)
{
//some code here
}
private void option3ToolStripMenuItem_Click(object sender, EventArgs e)
{
label1.Text = "Option 3 clicked!";
}
private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
{
option1ToolStripMenuItem_Click(this, null);
}
private void closeToolStripMenuItem_Click(object sender, EventArgs e)
{
this.Close();
}
private void btnWrite_Click(object sender, EventArgs e)
{
//code here
}
}
}
Where should I put the loop code? :(
Thanks in advance for ANY replay!!!

Add a Timer to your form:
set its Interval property to 60000 (one minute in milliseconds) and Enabled to True:
and attach an event handler to the Timer.Tick event, e.g. by double-clicking the timer in the Forms designer:
private void timer1_Tick(object sender, EventArgs e)
{
// do something here. It will be executed every 60 seconds
}

You would have to add a timer, and set the interval to 1000 miliseconds, and in the OnTick event you add the code with your loop
Timer tmr = null;
private void StartTimer()
{
tmr = new Timer();
tmr.Interval = 1000;
tmr.Tick += new EventHandler<EventArgs>(tmr_Tick);
tmr.Enabled = true;
}
void tmr_Tick(object sender, EventArgs e)
{
// Code with your loop here
}

You can't put any loop code in here.
In your designer look for the Timer control. When you have that, configure it to run every minute and place your code in the Timer_Tick event.
Or create a timer manually in code and respond to the event :) But for starters, doing it by the designer is easier!

Drag a Timer component on the Form and doubleclick it. There you go with the code.
The Timer component runs in the main thread so you can modify UI components without worrying.
Alternatively You could create a System.Timers.Timer, which has it's own thread and has some advantages, but possible caveats when modifying UI components. See http://msdn.microsoft.com/en-us/library/system.timers.timer.aspx

Try to use Background Worker and put the code in the backgroundWorker.DoWork or use a Timer

Use System.Timers.Timer:
System.Timers.Timer aTimer;
{
aTimer = new System.Timers.Timer();
aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
aTimer.Interval = 60000;
aTimer.Enabled = true;
}
private static void OnTimedEvent(object source, ElapsedEventArgs e)
{
Console.WriteLine("The Elapsed event was raised at {0}", e.SignalTime);
}
for using Timer see this tutorial: C# Timer

How you do it in Java platform?
I think Java should be the same with .net.
In fact, a form program is just normal program which contains a event dispatcher. The event dispatcher listen to the UI events and dispatch them to the event handlers. I think all the UI mode should like this, no matter Java or .net platform.
So generally speaking, you have 2 options:
Start the loop at beginning. In this case, you should insert your
code in the constructor of the Form.
Start the loop when user
click the button. In this case, you should insert your code in the
event handler function.
Yes, as others mentioned, you should use the timer. But this should after you know where your code should locate. You also can use a endless loop with a sleep call. But timer is a better solution.

Idea of timer is more better. But If you want to use threads. Then Follow this
Let me assume that You want to do it right from the start of program
You can write in body of function (event in fact) named Form1_Load as
Your actual code is just within while loop other code only to guide
I can guide if you don't know the use of threads in C#
bool button2Clicked = false;
private void Form1_Load(object sender, EventArgs e)
{
// A good Way to call Thread
System.Threading.Thread t1 = new System.Threading.Thread(delegate()
{
while (!button2Clicked)
{
// Do Any Stuff;
System.Threading.Thread.Sleep(60000); //60000 Millieconds=1M
}
});
t1.IsBackground = true; // With above statement Thread Will automatically
// be Aborted on Application Exit
t1.Start();
}