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
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 have a NotifyIcon and I set balloon text with MouseMove event. The balloon text comes from a database. This results continuous database query.
private void notifyIcon1_MouseMove(object sender, MouseEventArgs e)
{
//database operations.......
}
How can I prevent this? I want to set balloon text once when mouse on NotifyIcon.
Use the BalloonTipShown event (https://msdn.microsoft.com/en-us/library/system.windows.forms.notifyicon.balloontipshown(v=vs.110).aspx)
The behaviour you are looking for matched that event alot better then the MouseMove event
Another approach would be to add a Timer to your Form and set its Interval to a delay like 1 second. This delay would be how often the user could hit the database. Setup a Flag that gets reset by the Timer and check it in your NotifyIcon event. Something like:
private bool AllowUpdate = true;
private void notifyIcon1_MouseMove(object sender, MouseEventArgs e)
{
if (AllowUpdate)
{
AllowUpdate = false; // don't allow updates until after delay
// ... hit the database ...
// ... update your text ...
timer1.Start(); // don't allow updates until after delay
}
}
private void timer1_Tick(object sender, EventArgs e)
{
// reset so it can be updated again
AllowUpdate = true;
timer1.Stop();
}
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
}
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 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.