Customizing UISlider look

Question

To customize the visual look of a UISlider you can set the thumb and track images. Part of the track images gets stretched to the appropriate with. From the documentation:

Answer 1

I know it's late answer.

But I solved the problem as the following:

4 is the width of the round cap in the png file.

UIImage *minimum = [UIImage imageNamed:@"slider_minimum.png"];
[slider setMinimumTrackImage:[minimum stretchableImageWithLeftCapWidth:4 topCapHeight:0]
                      forState:UIControlStateNormal];