I'm trying to implement a timer for a checkbox. The binding for the checkbox is done using the CaptureColorBind property. When ever I click the capture color checkbox (captureColor = true), it needs to be checked for 5 seconds and then checkbox needs to be unchecked. I'm trying to print the datetime before and after the timer to verify. Its printing the before time properly, but the datetime I print in the elapsed event handler gets printed n times depending on the number of times I click the capture color checkbox. That is the first time I click, it prints the date and time once, the second time I click, it prints twice and so on. Not sure what I'm doing wrong.
private System.Timers.Timer timer = new System.Timers.Timer();
public bool CaptureColorBind
{
get
{
return this.captureColor;
}
set
{
this.captureColor = value;
if (captureColor == true)
{
Console.WriteLine(DateTime.Now.ToString());
Console.WriteLine();
timer.Elapsed += new ElapsedEventHandler(capturecolor_timer);
timer.Interval = 5000;
timer.Enabled = true;
}
if (null != this.PropertyChanged)
{
this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("CaptureColorBind"));
}
}
}
// Timer for capturecolor checkbox
private void capturecolor_timer(object sender, ElapsedEventArgs e)
{
timer.Enabled = false;
this.captureColor = false;
//this.colorCheckbox.IsChecked = false;
Console.WriteLine(DateTime.Now.ToString());
Console.WriteLine();
if (null != this.PropertyChanged)
{
this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("CaptureColorBind"));
}
}
You are adding a new event handler every time the value is set. You should only add it once.
Try adding the event handler in the object's constructor so it only gets set once, and just re-enabling the timer when the property is set.
private System.Timers.Timer timer = new System.Timers.Timer();
public MyObject()
{
timer.Elapsed += new ElapsedEventHandler(capturecolor_timer);
timer.Interval = 5000;
}
Related
I wanted to create a time-lapse control, for example, when the program starts, after time interval t1, trigger event A (e.g switch on), then wait after time interval t2, trigger event B (e.g.switch off), and this process will be executed periodically for n times.
What I have achieved so far is I could loop the two events only when t1=t2, I don't know how to make t1 and t2 two separate controllable variables.
public partial class Form1 : Form
{
private int counter; //counter to control the cycle times
private int EventIndex;//control the event status
private void InitializeTimer()
{
counter = 0;
EventIndex = 0;
timer1.Enabled = true; // Hook up timer's tick event handler.
this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
}
//function for switch the event status
private void UpdateEvent()
{
EventIndex = 1 - EventIndex; // loop event index between 1 and 0
if (EventIndex.Equals(1))
{
//Exceute command for event A
}
else
{
//Exceute command for event A
}
}
private void timer1_Tick(object sender, EventArgs e)
{
decimal t = numericUpDown1.Value; //time interval t between two events
int interval = Convert.ToInt32(t);
decimal n = numericUpDown2.Value; //periodically excute the process n times
int cycle = Convert.ToInt32(n);
//using the numeric input value to set up the interval time
timer1.Interval = interval
if (counter >= cycle)
{
// Exit loop code.
timer1.Enabled = false;
counter = 0;
}
else
{
UpdateEvent();
counter = counter + 1;// Increment counter.
}
}
}
Have UpdateEvent set the timer interval after an event:
private void UpdateEvent()
{
if (EventIndex.Equals(1))
{
timer1.Interval = //delay until event B;
}
else
{
timer1.Interval = //delay until event A;
}
}
I'll suggest you make two timer for each event.
timerA is interval t1, trigger event A.
timerB is interval t2, trigger event B.
By seperating timer, you may not accidentally change your timer interval into unexpected reults.
void UpdateEventA(){
if( counter >= cycle ){
timerA.Enable = false;
return;
}
// A working
timerA.Enable = false;
timerB.Enable = true;
}
void UpdateEventB(){
// B working
timerB.Enable = falsed;
timerA.Enable = true;
counter ++;
}
However if you have Event ABCDE and need to execute in sequence. I'll suggest you use one timer and calculate interval internally in single Tick event.
I have a focus changed event handler (uia) on a background MTA thread for updating a list of elements for the current active window which gets fired multiple times in one second when changing active window. I am trying to make it to go once and then wait for one second before handling any other events. Problem at the minute is that the timer is started but never triggered? I guess there is a better way of doing this? A code example would be great.
public void HandleFocusChangedEvent(IUIAutomationElement sender)
{
// A focus changed event has been sent by the the active window or some descendant of it.
// Check that this event hasn't arrived around the time we're removing the event handler on shutdown.
if (!_fAddedEventHandler)
{
return;
}
// All the event handler needs to do is notify the main UI thread that the
// list of elements should be refreshed to make sure it's showing the most current list.
// We only want to do this once every second So use a timer/counter
if (focusChangedCounter == 0)
{
controllerDispatcher.BeginInvoke(_focusChangedEventHandlerDelegate);
focusChangedCounter = 1;
if (focusChangedBufferTimer == null)
{
focusChangedBufferTimer = new System.Windows.Forms.Timer();
focusChangedBufferTimer.Tick += new EventHandler(focusChangedBufferTimer_Tick);
focusChangedBufferTimer.Interval = 1000;
focusChangedBufferTimer.Start();
}
}
}
private void focusChangedBufferTimer_Tick ( object sender, EventArgs e)
{
focusChangedCounter = 0;
focusChangedBufferTimer.Stop();
focusChangedBufferTimer = null;
}
Try this: With each event trigger, reset the timer.
public partial class Form1 : Form
{
Timer t = new Timer();
public Form1()
{
InitializeComponent();
t.Interval = 1000;
t.Tick += ((ss, ee) => {
t.Enabled = false;
focusChangedCounter = 0;
focusChangedBufferTimer.Stop();
focusChangedBufferTimer = null;
});
}
private void HandleFocusChangedEvent(object sender, EventArgs e)
{
t.Enabled = false;
t.Enabled = true;
}
}
I am new to coding and are having trouble.
I want to use a timer that will start upon pressing ScatterMode tab, it will start counting 4sec before running "Dosomething" function. This cycle will repeat itself until i decide to stop the program. But the problem i get is, this code only run correctly for like 2loop, after that the timer sort of go crazy LOL.
System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();
//ScatterMode Tab
private void Scatter_modeToolStripMenuItem_Click(object sender, EventArgs e)
{
timer.Interval = 4000;
timer.Enabled = true;
timer.Tick += new EventHandler(Dosomething);
timer.Start();
}
private void Dosomething (object sender, EventArgs e)
{
timer.Stop();
timer.Enabled = false;
Grab.buffer(out buffer, out status, 6000);
Scatter_mode(buffer);
pictureBox1.Refresh();
int done_grab = 1;
if (doneGrab == 1)
{
timer.Interval = 4000;
timer.Enabled = true;
timer.Tick += new EventHandler(Scatter_modeToolStripMenuItem_Click);
timer.Start();
done_grab = 0;
}
}
Adding a new event handler to a timer, to handle its tick event, inside the handler for the tick event will indeed cause the timer to go "crazy". Every time the timer raises its event, another event handler (that responds to events raised) will be added. This means the next time the timer ticks, the event code will run twice. Two new event handlers will be added. Next time the timer ticks, the code will run 4 times. 4 event handlers will be added ... and so on
Remove this line from your code:
timer.Tick += new EventHandler(Scatter_modeToolStripMenuItem_Click);
And move this line into your form's constructor:
timer.Tick += new EventHandler(Dosomething);
You only want to wire this event handler up once. Every time the timer's interval elapses, the code will run, once :)
I'll also do a bit of a peer review of your code, see the comments:
System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();
//ScatterMode Tab
private void Scatter_modeToolStripMenuItem_Click(object sender, EventArgs e)
{
timer.Interval = 4000; //can go in the constructor also; don't need to set repeatedly
timer.Enabled = true;
timer.Tick += new EventHandler(Dosomething); //move to constructor
timer.Start(); //this isn't needed - you already Enabled the timer, which started it
}
private void Dosomething (object sender, EventArgs e)
{
timer.Stop(); //use this
timer.Enabled = false; //or this. It's not required to do both
Grab.buffer(out buffer, out status, 6000); //if these lines crash then your timer will
Scatter_mode(buffer); //only restart if the toolstripmenuitemclick
pictureBox1.Refresh(); //above runs.. is it what you wanted?
int done_grab = 1; //not needed
if (doneGrab == 1) //this will always evaluate to true, it is not needed
{
timer.Interval = 4000; //the interval is already 4000, not needed
timer.Enabled = true; //careful; your timer may stop forever if the code above crashes
timer.Tick += new EventHandler(Scatter_modeToolStripMenuItem_Click); //remove
timer.Start(); //not needed
done_grab = 0; //not needed
}
}
I've checked the other questions in SO for timeout in C#, but since I'm a beginner, I don't really know how to implement them into my code. They look too sophisticated.
I have a text box and I added a click event. Upon click, user copies the content of the text box to the clipboard. To make the copy process noticeable to the user, I change the back color of the text box. Once the content is copied, I want to change the back color of the text box back to normal. So I need to set a timeout.
private void IDBox_Click(object sender, EventArgs e)
{
CopyToClipboard((TextBox)sender);
}
private void CopyToClipboard(TextBox textBox)
{
if (textBox.Text != "")
{
textBox.BackColor = System.Drawing.Color.MistyRose;
Clipboard.SetText(textBox.Text);
// set 200ms timeout and then change BackColor
//textBox.BackColor = System.Drawing.SystemColors.Window;
}
}
How can I set a timeout? An example would be great.
Not sure if that fits to your requirements (beginner?), but that will do a simple blinking by using Task and invoking text color changing back after delay:
textBox.BackColor = Color.MistyRose;
Task.Run(() =>
{
Thread.Sleep(200); // delay
this.BeginInvoke((MethodInvoker)delegate
{
textBox.BackColor = SystemColors.Window;
});
});
Use a Timer and change colour back in the Elapsed event.
Quick and dirty (untested) code to get you started:
private void CopyToClipboard(TextBox textBox)
{
if (textBox.Text != "")
{
textBox.BackColor = System.Drawing.Color.MistyRose;
Clipboard.SetText(textBox.Text);
// Create a timer with a 1 second interval.
System.Timers.Timer aTimer = new System.Timers.Timer(1000);
// Hook up the Elapsed event for the timer.
aTimer.Elapsed += OnTimedEvent;
// Only tick one time
aTimer.AutoReset = false;
// Start timer
aTimer.Enabled = true;
}
}
private void OnTimedEvent(Object source, ElapsedEventArgs e)
{
this.BeginInvoke((MethodInvoker)delegate
{
textBox.BackColor = System.Drawing.SystemColors.Window;
});
}
Supposed you have a textbox named test you can use the dispatcher timer in WPF or the Windows forms timer if you are working in windows forms.
test.Background = new SolidColorBrush(Colors.MistyRose);
Clipboard.SetText(test.Text);
var dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
dispatcherTimer.Tick += new EventHandler((s, x) =>
{
dispatcherTimer.Stop();
test.Background = new SolidColorBrush(Colors.White);
});
dispatcherTimer.Interval = new TimeSpan(0, 0, 0, 0, 200);
dispatcherTimer.Start();
I have a timer event setup and I would like to change how often the timer event happens by reading a number from a text box. If the box is '10' and you click the update button the event would trigger every 10ms then if you changed to '100' and clicked it would happen every 100ms and so on.
When I run the program however, i can speed up the event frequency (e.g. 100ms to 10ms) but I cannot slow it down (e.g. 10ms to 100ms). Here is the piece of my code that changes the timer when I click:
private void TimerButton_Click(object sender, EventArgs e)
{
getTime = ImgTimeInterval.Text;
bool isNumeric = int.TryParse(ImgTimeInterval.Text, out timerMS); //if number place number in timerMS
label2.Text = isNumeric.ToString();
if (isNumeric)
{
System.Timers.Timer timer = new System.Timers.Timer();
timer.Enabled = false;
timer.Interval = timerMS;
timer.Elapsed += new ElapsedEventHandler(timerEvent);
timer.AutoReset = true;
timer.Enabled = true;
}
}
public void timerEvent(object source, System.Timers.ElapsedEventArgs e)
{
label1.Text = counter.ToString();
counter = (counter + 1) % 100;
}
If anyone knows what I may be doing wrong it would be greatly appreciated.
The problem with this code is, that you create a new Timer each time you click the button. Try to create the timer outside the method. You think it's only goes faster, but instead multiple timers trigger the timerEvent
private System.Timers.Timer _timer;
private void CreateTimer()
{
_timer = new System.Timers.Timer();
_timer.Enabled = false;
_timer.Interval = 100; // default
_timer.Elapsed += new ElapsedEventHandler(timerEvent);
_timer.AutoReset = true;
_timer.Enabled = true;
}
private void TimerButton_Click(object sender, EventArgs e)
{
bool isNumeric = int.TryParse(ImgTimeInterval.Text, out timerMS); //if number place number in timerMS
label2.Text = isNumeric.ToString();
if (isNumeric)
{
_timer.Interval = timerMS;
}
}
public void timerEvent(object source, System.Timers.ElapsedEventArgs e)
{
label1.Text = counter.ToString();
counter = (counter + 1) % 100;
}
Make sure that the CreateTimer is called in the constructor/formload. Also you can now stop the timer within another button event. With _timer.Enabled = false;
You're always creating a new timer and never stopping the old timer. When you "change" it from 100 to 10 your 100ms timer is still firing every 100 ms, so every 100ms two timers are firing at around the same time.
You need to "remember" the old timer so that you can stop it. Or, better yet, just have only one timer that you change the interval on.
private System.Timers.Timer timer = new System.Timers.Timer();
public Form1()
{
timer.Enabled = false;
timer.AutoReset = true;
timer.Elapsed += timerEvent;
}
private void TimerButton_Click(object sender, EventArgs e)
{
getTime = ImgTimeInterval.Text;
bool isNumeric = int.TryParse(ImgTimeInterval.Text, out timerMS); //if number place number in timerMS
label2.Text = isNumeric.ToString();
if (isNumeric)
{
timer.Interval = timerMS;
timer.Enabled = true;
}
}
Well the basic problem is that you're building a new one every time. Make a private timer:
private System.Timers.Timer _timer = new System.Timers.Timer();
and then fix it up when the button is clicked:
if (isNumeric)
{
_timer.Stop();
_timer.Interval = timerMS;
_timer.Start();
}
and then in the .ctor, do this:
_timer.Elapsed += new ElapsedEventHandler(timerEvent);
Now you have a single timer that you are just modifying as the user changes the value in the text box.