Develop Reference

How to start a countdown timer event from the click of a button?

so I have coded a timer where you are able to increase the hours, minutes and seconds by separate button click events. My aim was to set the hours, minutes and seconds and when I click a start button, the code will start to countdown. At the moment I can only seem to get the time to countdown as soon as the time is incremented. Anything I have tried has not worked with the start button click event, any idea's?
public partial class Form1 : Form
{
System.Windows.Forms.Timer timer;
TimeSpan countdownClock = TimeSpan.Zero;
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
AddTimeToClock(TimeSpan.FromSeconds(10));
}
private void Form1_Load(object sender, EventArgs e)
{
timer = new System.Windows.Forms.Timer();
timer.Interval = (int)TimeSpan.FromSeconds(1).TotalMilliseconds;
timer.Tick += OnTimeEvent;
DisplayTime();
}
private void DisplayTime()
{
lblTime.Text = countdownClock.ToString(#"hh\:mm\:ss");
}
private void OnTimeEvent(object sender, EventArgs e)
{
// Subtract whatever our interval is from the countdownClock
countdownClock = countdownClock.Subtract(TimeSpan.FromMilliseconds(timer.Interval));
if (countdownClock.TotalMilliseconds <= 0)
{
// Countdown clock has run out, so set it to zero
// (in case it's negative), and stop our timer
countdownClock = TimeSpan.Zero;
timer.Stop();
}
// Display the current time
DisplayTime();
}
private void AddTimeToClock(TimeSpan timeToAdd)
{
// Add time to our clock
countdownClock += timeToAdd;
// Display the new time
DisplayTime();
// Start the timer if it's stopped
if (!timer.Enabled) timer.Start();
}
private void button2_Click(object sender, EventArgs e)
{
AddTimeToClock(TimeSpan.FromMinutes(1));
}
private void button3_Click(object sender, EventArgs e)
{
AddTimeToClock(TimeSpan.FromMinutes(10));
}
private void Start_Click(object sender, EventArgs e)
{
}
}
I have also tried adding a timer interval scale using this command
private static readonly int timeScale = 6
to adjust the countdownClock in the OnTimeEvent, and multiply by the scale.
countdownClock = countdownClock.Subtract(timeScale * TimeSpan.FromMilliseconds(timer.Interval));

it's your
// Start the timer if it's stopped
if (!timer.Enabled) timer.Start();
You are always starting your clock on time incrementation. Start your clock on btn click.

User input for timer countdown

I would like to make my timer count down based on user input.
This is what my form looks like:
and this is my code:
private int counter=80;
DateTime dt = new DateTime();
private void button1_Click(object sender, EventArgs e)
{
progressBar1.Maximum = counter * 1000;
progressBar1.Step = 1000;
timer1 = new System.Windows.Forms.Timer();
timer1.Tick += new EventHandler(timer1_Tick);
timer1.Interval = 1000;
timer1.Start();
textBox1.Text = counter.ToString();
}
private void timer1_Tick(object sender, EventArgs e)
{
counter--;
progressBar1.PerformStep();
if (counter == 0)
{
timer1.Stop();
}
textBox1.Text = dt.AddSeconds(counter).ToString("mm:ss");
}
private void Form1_Load(object sender, EventArgs e)
{
timer1.Enabled = false;
}
private void button2_Click(object sender, EventArgs e)
{
timer1.Stop();
textBox1.Clear();
progressBar1.Value = 0;
}
How can I update the timer if the user enters a new value in the textbox?

Attach an OnTextChanged eventhandler to your textbox1. Stop the timer when textinput changes
protect void textinput1_OnTextChange(object sender, EventArg e) {
button2_Click(sender, e);
}
Or you can disable user input when timer starts and re-enable it once timer stopped.

Simply set textbox enabled value to false at start button clicked. And enable it again at stop of timer or checked on cancel button. Here is a code:
textBox1.Enabled = false;And
textBox1.Enabled = true;

Stop webBrowser control if document does not complete

I am using a C# webBrowser control using the DocumentCompleted -
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
I am then navigating -
webBrowser1.Navigate("myUrl")
However if the request to that server hangs, i.e. the page does not complete after say 10 seconds, how could I implement the webBrowser1.Stop();?
I did try to implement a count, that if it got to 20 i.e. the webBrowser1_DocumentCompleted went into an infinite loop (the page would not complete) then stop however not sure if this is the most straightforward way of doing htis?

This might be in really bad practice so I apologize but you could use a boolean control with a timer to check whether or not the document has completed and if it hasn't, close the webBrowser.
First of all add a timer(assuming its called Timer1) to your form, setting interval to 1000 and create an int and bool control.
int timeLeft;
bool hasCompleted = false;
Run your URL as normal and start your timer
webBrowser1.Navigate("myUrl");
timeLeft = 10;
Timer1.Start();
And your timer should look like this;
private void timer1_Tick(object sender, EventArgs e)
{
if(timeLeft > 0) {
timeLeft = timeLeft - 1;
}
if(timeLeft = 0 && !hasCompleted)
{
timer1.Stop();
webBrowser1.Stop();
}
else{
timer1.Stop();
}
}
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
hasCompleted = true;
//your code
}

I have tried to achieve this using the timer.
I just added a timer and set the interval.
Here is the code
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
timer1.Tick += timer1_Tick;
webBrowser1.DocumentCompleted += new
WebBrowserDocumentCompletedEventHandler( webBrowser1_DocumentCompleted);
LoadBrowser();
}
void timer1_Tick(object sender, EventArgs e)
{
timer1.Enabled = false;
webBrowser1.DocumentText = "Cancelled";
}
void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
if (timer1.Enabled)
{
MessageBox.Show("Page Loaded succesfully");
}
}
private void LoadBrowser()
{
timer1.Enabled = true;
webBrowser1.Url = new Uri("http://www.microsoft.com");
}
}

Timer using label

So, this seems to be a common question but I can't seem to figure out a way to do this. I have a C# Form application that goes out to an imap client and processes the emails. I want to have a timer formatted like "08:45" (for 8 minutes and 45 seconds) displayed on the form to let the user know how long it has been since they clicked the button to start the process.
I want the timer to stop once my process ends obviously.
private void btn_ImportEmail_Click(object sender, EventArgs e)
{
this.timer = new System.Timers.Timer();
this.lblTimer = new System.Windows.Forms.Label();
((System.ComponentModel.ISupportInitialize) (this.timer)).BeginInit();
this.timer.Elapsed += new System.Timers.ElapsedEventHandler(this.OnTimerElapsed);
//connect to email and download messages...
this.timer.Enabled = true;
this.timer.SynchronizingObject = this;
timer.Interval = 1000;
timer.Start();
for (int I = 0 ; I <= messages.count() - 1; I++)
{
//process emails
}
timer.EndInit();
}
private void timer1_Tick(object sender, EventArgs e)
{
lblTimer.Text = DateTime.Now.ToString("mm:ss");
}
private void OnTimerElapsed(object sender, System.Timers.ElapsedEventArgs e)
{
lblTimer.Text = DateTime.Now.ToString("mm:ss");
// lblTimer.Text = string.Format("{0:mm:ss}", DateTime.Now);
}

The following SO Q/A might answer your question...
Display the running time of part of a program in a label
I would recommend changing the format to your needs.

The first thing that I see is that you are using DateTime.Now which will give you the current minutes and seconds, not elapsed minutes and seconds. The second thing and the main thing is that since you are processing your emails in your main UI's thread you are preventing your label from being updated, you would be better off looking at using a background worker instead.
Edit based on Idle_Mind's comment added DateTime Object instead of counter.
public partial class Form1 : Form
{
BackgroundWorker bgw = new BackgroundWorker();
Timer timer = new Timer();
DateTime startTime;
public Form1()
{
InitializeComponent();
timer.Interval = 1000;
timer.Tick += timer_Tick;
bgw.DoWork += bgw_DoWork;
bgw.RunWorkerCompleted+=bgw_RunWorkerCompleted;
}
void timer_Tick(object sender, EventArgs e)
{
label1.Text =((TimeSpan)DateTime.Now.Subtract(startTime)).ToString("mm\\:ss");
}
void bgw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
timer.Stop();
}
void bgw_DoWork(object sender, DoWorkEventArgs e)
{
for (int I = 0 ; I <= messages.count() - 1; I++)
{
//process emails
}
}
private void button1_Click(object sender, EventArgs e)
{
bgw.RunWorkerAsync();
startTime = DateTime.Now;
timer.Start();
}
}

How to set time interval to button_click in C# windows form application

Here the below code enables the particular bit as high in parallel port.How to set time interval for the button click in windows form.If i set the time interval to 2 seconds the timer should start then 2 seconds after that it should stop automatically.
private void button1_Click(object sender, EventArgs e)
{
PortAccess.Output(888,1);
}
can u please let me know any suggestion or example to do this.Inside this button_click.

So you just want to clear the bit 2 seconds later? Something like this should work:
private void button1_Click(object sender, EventArgs e)
{
// Prevent multiple button clicks
button.Enabled = false;
PortAccess.Output(888, 1);
Timer timer = new Timer { Interval = 2000 };
timer.Tick += HandleTimerTick;
timer.Start();
}
private void HandleTimerTick(object sender, EventArgs e)
{
Timer timer = (Timer) sender;
timer.Stop();
timer.Dispose();
button.Enabled = true;
PortAccess.Output(888, 0);
}
You may find it simpler to set up the timer just once, and store it as an instance variable. Then you could attach the Tick event and set the interval on construction, and add it to the components of the form so that it's automatically disposed. Your methods would then be:
private void button1_Click(object sender, EventArgs e)
{
button.Enabled = false;
PortAccess.Output(888, 1);
timer.Start();
}
private void HandleTimerTick(object sender, EventArgs e)
{
timer.Stop();
button.Enabled = true;
PortAccess.Output(888, 0);
}