Creating the Slider

To create a slider, you allocate it and initialize it with a frame just like any other UIKit control:

slider = [[UISliderControl alloc] initWithFrame: CGRectMake(0.0f, 32.0f, 320.0f, 20.0f)];

Next, you specify its minimum and maximum values with the setMinValue: and setMaxValue: calls. The "setShowValue" call is optional. When set to YES, it displays the current value to the right of the slider (as shown here) so the user gets instant feedback.

[slider setMaxValue:100.0f];
[slider setMinValue:0.0f];
[slider setShowValue:YES];

Now you must add a target for events. Here, I tell the slider to issue the handleSlider: method for mouse dragged events. Fortunately, the iPhone seems to use standard NextStep event equivalents, so 7 corresponds to NSRightMouseDragged, 1 to NSLeftMouseDown and 2 to NSLeftMouseUp. Since the iPhone only supports one button, the right and left gets a little confused.

[slider addTarget:self action:@selector(handleSlider:) forEvents:7];

Next, add the behavior for the message that gets called. In this example, I just write the [slider value] to a text view.

- (void) handleSlider:(id)sender{
[textView setText:[NSString stringWithFormat:@"End Value: %f", [slider value]]];

}


Reference:
// http://www.tuaw.com/2007/09/04/iphone-coding-using-the-slider/