ASP.NET combo selectedIndexChanged event is not called

I have written a selectedIndexChanged event for combo on a web page in ASP.NET (C#). 开发者_如何学编程This event is not called. When in debug, the control does not go into the code this event. What can be the reason?

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Set AutoPostBack property to true.

If it doesn't help, check this answer: DropDownList annoyance: same value won't trigger event