I want to stop a timer but in the middle of the tick, before the tick finishes. But when I use a button to stop the timer, it only stops it after the tick finishes all his functions.
I'm using 4 radiobuttons and a timer that keeps changing the selected radiobutton. When I press the Stop button, my timer stops and I need to know what radiobutton is selected, but the timer just stops after the tick finishes, so the selected radiobutton changes.
The code is:
namespace teste_bola
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
Int32 x = 1000;
private void ini_Click(object sender, EventArgs e)
{
timer1.Enabled = true;
}
private void par_Click(object sender, EventArgs e)
{
timer1.Enabled = false;
}
private void t_Click(object sender, EventArgs e)
{
Int32 Intervalo = Convert.ToInt32(tb.Text);
x = Intervalo;
}
private void timer1_Tick(object sender, EventArgs e)
{
r3.Select();
System.Threading.Thread.Sleep(x);
r2.Select();
System.Threading.Thread.Sleep(x);
r1.Select();
System.Threading.Thread.Sleep(x);
r2.Select();
System.Threading.Thread.Sleep(x);
r3.Select();
System.Threading.Thread.Sleep(x);
r4.Select();
System.Threading.Thread.Sleep(x);
}
}
}
You can introduce a flag bool shouldStop , set it when button is clicked, and check it from the Tick handler. If it is true, then just exit the method.
I'm not following what you are trying to accomplish in you code but it seems to me like you are not using the timer correctly.
You should do something like:
On each timer.Tick change the selected radiobox.
What you are actually doing is:
On each timer.Tick change through all radiobox's with a time interval between changes.
This means that on the first timer timeout the tick code is executed.
On the second timer timeout the first tick job was not yet finnished.
This will lead to erratic behaviour to say the least.
My advice. Add the radio buttons to a ArrayList. Then cicle select between each of the ArrayList items on a Timer tick.
try the following
private void timer1_Tick(object sender, EventArgs e)
{
r3.Select();
System.Threading.Thread.Sleep(x);
if(timer1.Enabled == false) return;
r2.Select();
System.Threading.Thread.Sleep(x);
if(timer1.Enabled == false) return;
r1.Select();
System.Threading.Thread.Sleep(x);
if(timer1.Enabled == false) return;
r2.Select();
System.Threading.Thread.Sleep(x);
if(timer1.Enabled == false) return;
r3.Select();
System.Threading.Thread.Sleep(x);
if(timer1.Enabled == false) return;
r4.Select();
System.Threading.Thread.Sleep(x);
}
You can face this behaviour because your thread is sleeping during the execution of the timer1_Tick and thus there might be a queye of events.
As alex proposed you can add a flag, but you should check it after every sleep or, even better, put your animation in the different thread.
Related
Here's my code
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
System.Timers.Timer myTimer = new System.Timers.Timer();
myTimer.Elapsed += new ElapsedEventHandler(DisplayTimeEvent);
myTimer.Interval = Convert.ToInt32(textBox5.Text);
if (checkBox1.Checked)
{
myTimer.Start();
}
else
{
myTimer.Stop();
}
}
It should stop repeating the function when unchecked, but it doesn't. What's wrong with it?
I recommend that you stop using System.Timers.Timer and start using a System.Windows.Forms.Timer component.
Begin by removing your myTimer-related code (the entire body of checkBox1_CheckedChanged will need to be replaced with code from below.)
Add a Timer component to your form using the designer and name it myTimer. This will add a System.Windows.Forms.Timer field to your form called myTimer.
Using the designer, set the Tick event handler of myTimer to DisplayTimeEvent. (Or add a new handler and replace its code with the code of your DisplayTimeEvent function.)
Then change your checkBox1_CheckedChange function to look like this:
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
if (int.TryParse(textBox5.Text, out int interval)) {
this.myTimer.Interval = interval;
}
this.myTimer.Enabled = checkBox1.Checked;
this.textBox5.Enabled = !checkBox1.Checked;
}
I also recommend adding the following handler to textBox5 to perform the bare minimum validation so you can't crash your app by entering an interval of 0 or the empty string, or some text that is not an integer.
private void textBox5_TextChanged(object sender, EventArgs e)
{
this.checkBox1.Enabled = (int.TryParse(textBox5.Text, out int interval) && interval > 0);
}
The System.Windows.Forms.Timer's Tick handler will be called in the UI thread, meaning it will be safe to do things like update labels of your form in that handler. In contrast to that, the System.Timers.Timer will be called on a worker thread and will require that you take on some some thread-management responsibilities you likely don't want to incur, such as invoking your UI updates back to the main UI thread. See Why there are 5 Versions of Timer Classes in .NET? for more info.
Everytime checkbox1 is changed, new Timer is created. When checkbox is ticked, created timer is active and will invoke DisplayTimeEvent forever. When checkbox is unticked, you stop another Timer, which was just created.
You need to create Timer only once (probably when form is created), or when checkbox1 is changed first time:
private System.Timers.Timer myTimer;
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
if (myTimer == null) {
myTimer = new System.Timers.Timer();
myTimer.Elapsed += new ElapsedEventHandler(DisplayTimeEvent);
myTimer.Interval = Convert.ToInt32(textBox5.Text);
}
if (checkBox1.Checked)
{
myTimer.Start();
}
else
{
myTimer.Stop();
}
}
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
After a button is clicked in a Windows form application written in C#, how to wait for another button to be clicked? Meanwhile I am updating a datagridview dynamically by current information.
EDIT
After button1 is clicked, I want to repeatedly update a dataGridView with current information and when button2 is clicked I want to stop updating the dataGridView.
Use Timer Class.
public partial class Form1 : Form
{
System.Windows.Forms.Timer timer;
public Form1()
{
InitializeComponent();
//create it
timer = new Timer();
// set the interval, so it'll fire every 1 sec. (1000 ms)
timer.Interval = 1000;
// bind an event handler
timer.Tick += new EventHandler(timer_Tick);
//...
}
void timer_Tick(object sender, EventArgs e)
{
//do what you need
}
private void button1_Click(object sender, EventArgs e)
{
timer.Start(); //start the timer
// switch buttons
button1.Enabled = false;
button2.Enabled = true;
}
private void button2_Click(object sender, EventArgs e)
{
timer.Stop(); //stop the timer
// switch buttons back
button1.Enabled = true;
button2.Enabled = false;
}
From MSDN:
A Timer is used to raise an event at user-defined intervals. This
Windows timer is designed for a single-threaded environment where UI
threads are used to perform processing. It requires that the user code
have a UI message pump available and always operate from the same
thread, or marshal the call onto another thread.
When you use this timer, use the Tick event to perform a polling
operation or to display a splash screen for a specified period of
time. Whenever the Enabled property is set to true and the Interval
property is greater than zero, the Tick event is raised at intervals
based on the Interval property setting.
So you have button A and button B. When button A is pressed you want to wait for button B to be pressed, then do something special? Without more information the simplest way is something like this:
private void OnButtonAClicked(object sender, EventArgs e)
{
ButtonA.Enabled = false;
ButtonA.Click -= OnButtonAClicked;
ButtonB.Click += OnButtonBClicked;
ButtonB.Enabled = true;
}
private void OnButtonBClicked(object sender, EventArgs e)
{
ButtonB.Enabled = false;
ButtonB.Click -= OnButtonBClicked;
// Do something truly special here
ButtonA.Click += OnButtonAClicked;
ButtonA.Enabled = true;
}
This code will toggle(initial state; button A is enabled, button B is disabled), when button A is pressed, button B becomes enabled and processes events, etc.
Use the BackgroundWorker http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx
It doesn't freeze the UI, support ProgressBar, also it can be async. At the link you will see a good example with same functional that you want (start some task by click on one button and cancel it by click on another button).
I am making a application where i would like to log in with a face detection. But this is not real, its just to make ik look like its scanning.
So when i press the LOG IN button, the kinect takes my picture and show me the picture, on top of it is showing me in a text that its scanning.
Now i am stuck with the following issue, when i press the login button, the scanning label appears, but i would like to fire an other event that takes me to the next page, the homepage.
So i want the SCANNING label appearing for 3 seconds, and then the page should change.
This is what i tried, i worked with a timer, but that doesnt do annything.
private void ActionButton_Click(object sender, System.EventArgs eventArgs)
{
_main.TakePicture();
identifyBox.Source = _main.source.Clone();
scanningLabel.Visibility = Visibility.Visible;
_storyboard = (Storyboard)FindResource("scanningSB");
//_storyboard.Begin();
Start();
}
private void Start()
{
_tm = new Timer(3000);
_tm.Elapsed += new ElapsedEventHandler(_tm_Elapsed);
_tm.Enabled = true;
}
void _tm_Elapsed(object sender, ElapsedEventArgs e)
{
if (_tm == new Timer(3000))
{
((Timer)sender).Enabled = false;
_main.ContentPage.Children.Clear();
_main.ContentPage.Children.Add(_homeScreen);
}
}
Okay i removed the if statement, but now it fires every 3 seconds a method.
How can i make it work 1 time.
Ok even this works, now i my ContentPage wont change? It gives me this error: The calling thread cannot access this object because a different thread owns it.
What can be wrong?
I think you can remove condition
if (_tm == new Timer(3000))
and keep it simple
void _tm_Elapsed(object sender, ElapsedEventArgs e)
{
((Timer)sender).Enabled = false;
_main.ContentPage.Children.Clear();
_main.ContentPage.Children.Add(_homeScreen);
}
when you set _tm = new Timer(3000); it will set the time to fire event after 3 seconds..
Change the _tm_Elapse to this:
void _tm_Elapsed(object sender, ElapsedEventArgs e)
{
if (_tm == (sender as Timer))
{
_main.ContentPage.Children.Clear();
_main.ContentPage.Children.Add(_homeScreen);
}
}
Edit for answering:
"I just want it 1 time to fire after 3 sec"
void _tm_Elapsed(object sender, ElapsedEventArgs e)
{
if (_tm == (sender as Timer))
{
_tm.Stop();
_main.ContentPage.Children.Clear();
_main.ContentPage.Children.Add(_homeScreen);
}
}
This is even simpler, and it will only run once per call, the three second timer is built in, and furthermore, it won't disable other program functionalities while it is running:
async Task Start()
{
await Task.Delay(3000);
_main.ContentPage.Children.Clear();
_main.ContentPage.Children.Add(_homeScreen);
}
I was wondering if anyone knows how to use a dialog box to create a hold down button event. Here is the scenerio:
a user would like to shutdown their system, but because it is critical that they confirm, that user must hold the button for 5 seconds before the action can be done.
I am trying to do it in a yes no scenario ie.
To confirm shutdown please hold "Yes" for 5 seconds.
Anyone done this before able to offer a little help/insight?
Try using a button's Mouse_Down & Mouse_Up event, and a timer (this assumes you're using WinForms).
private void button1_MouseDown(object sender, MouseEventArgs e)
{
if (this.timer1.Enabled == false)
{
this.timer1.Interval = 5000;
this.timer1.Enabled = true;
}
}
private void timer1_Tick(object sender, EventArgs e)
{
this.timer1.Enabled = false;
MessageBox.Show("Shutdown!");
}
private void button1_MouseUp(object sender, MouseEventArgs e)
{
timer1.Enabled = false;
}
You could capture the button press on 'mousedown', and start a 5-second timer. Once the timer completes, shutdown is initiated. If a 'mouseup' event happens, it could stop and reset the timer.
Sure, handle BOTH the mousedown event and the mouseup event. Start a timer on the mousedown and see how long it has run on the mouseup. Done!
You could do this any number of ways. The first that comes to my mind would be to spin off a thread that waits 5 seconds and is simply aborted if the user's mouse comes back up.
Thread shutdown;
private void button1_MouseDown(object sender, MouseEventArgs e)
{
shutdown = new Thread(()=>ShutDown());
shutdown.Start();
}
private void ShutDown()
{
Thread.Sleep(5000);
Console.Write("5 seconds has elapsed");
// Do something.
}
private void button1_MouseUp(object sender, MouseEventArgs e)
{
if (shutdown != null)
{
shutdown.Abort();
shutdown = null;
}
}
Low overhead and you're not adding additional supporting controls for something this simple.
Why bother when you can just use getAsyncKeyState()? Tell them to hold down 'y' for 5 seconds. You can find a reference here: http://www.pinvoke.net/default.aspx/user32.getasynckeystate
Or you can do it your way and start a timer on MouseDown, then on MouseUp, end the timer and then see if it's more or less than 5 seconds. http://msdn.microsoft.com/en-us/library/system.windows.forms.control.mousedown%28VS.71%29.aspx
You can use the Form.MouseDown events do detect that the user has pressed the mouse button. In the event handler, check to see if cursor is over the button or not (the event is passed in the coordinates of the cursor). You can then enable a timer which will tick in 5 seconds, and perform the shutdown when the timer ticks.
When the user first clicks YES, start a timer that repeatedly checks if the mouse location is inside of the button. After 5 seconds has elapsed, proceed with the shutdown. If the user moves the mouse out of the button, stop the timer.
private DateTime mouseDownTime;
private void Button_MouseDown(object sender, MouseButtonEventArgs e)
{
mouseDownTime = DateTime.Now;
}
private void Button_MouseUp(object sender, MouseButtonEventArgs e)
{
if (mouseDownTime.AddSeconds(5) < DateTime.Now)
MessageBox.Show("You held it for 5 seconds!");
}
You can set up a timer on the MouseDown event, and if the mouse capture changes (check the MouseCaptureChanged event) to false before the timer event fires, cancel the timer.