how to add uipickerview with uibutton programmaticaly in iphone

Im new to iPhone development.Now im doing application in that i want to add pickerview开发者_如何学编程 with button without using IB.Here i added pickerview and button programmaticaly in iphone.But When i run this application in pickerview I added some names that was not showing.It was showing only empty pickerview and when i click button the pickerview displayed in top of the view not in down.I searched in all sites but there is no data for this pickerview with button.I added pickerview view in uiaction sheet and i declared pickerview.

Can any one plz give code for this uipickerview with uibutton programmaticaly in iphone.

Thank you in advance.

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Have you add in main view..? Like [self.view addSubview:???];