Pickers like a keyboard

Is it possible to get a double picker to appear from the bottom of a screen when a certain button is selected? And is it possible to remove a value from a picker if 开发者_如何学JAVAit was already selected?

Of course it's possible. I did that for an app just this summer. But you'll have to code the component yourself.

My suggestion is to create a class which has a UIPickerView member; this class, when instantiated and sent a message (like -showInView:), will make the view slide up. You'll need to have a delegate protocol for the class; it will probably make sense to have its delegate also implement UIPickerViewDelegate and UIPickerViewDataSource.