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Editorial Team
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Asked: 2026-06-03T19:11:57+00:00

In the UI thread I have a piece of code that goes like this:

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In the UI thread I have a piece of code that goes like this:

SomeForm form = new SomeForm();
(...)
form.Show();

SomeForm class particularly has a System.Windows.Forms.Timer instance as a member that is being initialized by auto-generated code of InitializeComponent() that looks like this:

this.UploadStatusTimer.Enabled = true;
this.UploadStatusTimer.Interval = 1000;
this.UploadStatusTimer.Tick += new System.EventHandler(this.UploadStatusTimer_Tick);

form.Show() will in the end raise Form.Load event that is being handled by SomeForm_Load(object sender, EventArgs e).

My question is: is there a possibility that UploadStatusTime_Tick was being processed before SomeForm_Load?

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1 Answer

  1. Editorial Team

    What you are asking is “can it take longer than one second from the time I construct my form for the Load event to fire?”

    Beyond the theoretical answer of “yes, this is always possible” it really comes down to how long (…) takes in your example code. The timer is going to start counting down as soon as Enabled is set to true (when it is constructed).

    It’s important to note that UI interactions are processed via a message pump. So thinking of the winforms timer, the timer itself is off running in the background (outside of .net even; it is using the native windows timer) and when the timer expires it sends a message to your application, which then queues a message on the message pump that says “hey, timer tick happened.” Same thing applies to your form load event, it is triggered via a message on the message pump. So if the timer expires before the form “loads” then the timer message will be in front of the ‘form load’ message on the queue and get processed first.

    If you’re interested in learning more, there many articles or stack overflow questions on the winforms message pump (or message loop as some may call it).

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