Countdown after clicking a button that goes from 10 to 0 setting text on a label C#

问题

My problem is very simple but I can't figure it out, so I need your help.

The problem is that I have a button and a label in a form, I simply want to click the button and see the label countdown from 10 to 0 and after that happens the form closes, that simple, can someone help me with this?

BTW, my real app is a form that shows video in real time from my webcam and the idea is to click the button, see the count down and when it finishes the appp saves the current frame as an image.

Thanks in advice!

回答1:

Using WindowsFormsApplication u can do it like this:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        timer1.Enabled = false; // Wait for start
        timer1.Interval = 1000; // Second
        i = 10; // Set CountDown Maximum
        label1.Text = "CountDown: " + i; // Show
        button1.Text = "Start";
    }

    public int i;

    private void button1_Click(object sender, EventArgs e)
    {
        // Switch Timer On/Off
        if (timer1.Enabled == true)
        { timer1.Enabled = false; button1.Text = "Start"; }
        else if (timer1.Enabled == false)
        { timer1.Enabled = true; button1.Text = "Stop"; }
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        if (i > 0)
        {
            i = i - 1;
            label1.Text = "CountDown: " + i;
        }
        else 
        { timer1.Enabled = false; button1.Text = "Start"; }
    }
}

You only need a label, a button and a timer.

回答2:

It sounds like you probably just need three things:

A counter in your class as an instance variable
A timer (System.Windows.Forms.Timer or a DispatcherTimer depending on what UI framework you're using)
A method handling the timer's Tick even which decrements the counter, updates the UI, and stops the timer + takes a snapshot if the counter reaches 0

You can do all of this without any other threads.

回答3:

use this code. put one timer,label and button.

public partial class Form1 : Form
{

    public Form1()
    {
        InitializeComponent();
        timer1.Tick += new EventHandler(timer1_Tick);
    }
    private static int i = 10;
    private void button1_Click(object sender, EventArgs e)
    {
        label1.Text = "10";
        timer1.Interval = 1000;
        timer1.Start();
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        label1.Text = (i--).ToString();
        if (i < 0)
        {
            timer1.Stop();
        }
    }
}

来源：https://stackoverflow.com/questions/11682668/countdown-after-clicking-a-button-that-goes-from-10-to-0-setting-text-on-a-label

标签

multithreading

timer

countdown