ComboBox.SelectedIndexChanging?

How can I handle an combobox selected index event before the index changes ? Winforms doesnot provide any sort of ComboBox.SelectedIndexCh开发者_StackOverflow中文版anging event !

Thanks

I achieved it using ComboBox.DropDown

No you didn't. Use the up/down arrow keys to fire the event without using the dropdown.

To use the SelectedIndexChanged event for this, you need a time machine that goes back by less than a microsecond. It's really unclear why you need this but you can probably get one by deriving your own class from ComboBox. Like this:

using System;
using System.Windows.Forms;

class MyComboBox : ComboBox {
    protected override void OnSelectedIndexChanged(EventArgs e) {
        // Here
        //...
        base.OnSelectedIndexChanged(e);
    }
}

Insert the code at the dots. You could for example raise your own event there.

I achieved it using

ComboBox.DropDown;

Because my aim was to 'do something' before the combobox opens.