如何在 C# windows 表单应用程序的文本属性中显示当前日期和时间？

Question

I want to show the current date and time in live in the title of my C# windows form Application.

My resource says that I need to use datetime.now.tostring(); to do so, but I don't know how. Any ideas?

Answer 1

You want to display the current date and time in the title bar of your Form using its Text property. The simplest way to update the time continuously is to use System.Windows.Forms.Timer which issues its ticks on the UI thread.

Using other timers (eg System.Timers.Timer ) or updating UI controls from background workers generally can be tricky. If your WinForms app might end up being ported to an iOS or Android device, there are better more-portable alternatives. A good practice for handling events generated by backgound tasks is to use BeginInvoke to ensure that the control is updated on the UI thread.

In this straightforward case however, simply handle the Tick event:

• Obtain the current timestamp using the static DateTime.Now property.
• Format the Text property using DateTime standard format strings .

---

Minimal Example

public partial class MainForm : Form
{
    public MainForm() => InitializeComponent();
    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);
        _timer.Tick += onTimerTick;
        _timer.Start();
    }

    private void onTimerTick(object? sender, EventArgs e)
    {
        var now = DateTime.Now;
        Text = $"Main Form - {now.ToShortDateString()} {now.ToLongTimeString()}";
    }

    System.Windows.Forms.Timer _timer= new System.Windows.Forms.Timer { Interval= 1000 };
}

Answer 2

You can use this, it will work on runtime:

public partial class FormMain : Form
    {
        public FormMain()
        {
            InitializeComponent();
            this.Text = "Your title here";
        }
    }