Member Avatar for spowel4

I am populating a combobox with a list of names and the list contains approximately 7600 items.
Here is the code:

foreach (string customerName in customerNames)
{
    comboBoxCustName.Items.Add(customerName);
}

This loop takes nearly one minute to complete (58.6 seconds to be precise). I don't think it should take that long, can someone please offer some ideas as to why it's taking so long?

Edited by spowel4
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Member Avatar for spowel4

I just solved this on my own, thought I'd post what I changed in case anyone else has this problem.
I moved the code from the form load event to immediately after the InitializeComponent() line. Now the combobox populates in about 1.5 seconds.

Member Avatar for Ketsuekiame

For future reference, if you're doing a cluster update like this, before you populate the control you should set Enabled = false; as it (stops it firing events) and SuspendLayout (if you're changing any control layout properties) do your updates and then call ResumeLayout and set Enabled = true; for the control.

I'm guessing that you had an event attached to your combo box causing it to fire everytime you added a value?

Member Avatar for spowel4

I have two events attached - KeyDown and SelectedIndexChanged. You're thinking one of these events was probably firing each time an item was added to the combobox? I saw somewhere where the combobox has to redraw itself every time an item is added and that slows it way down; their solution was to move the combobox population into the form constructor, which is what I did.

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