UISlider* slider = [[UISlider alloc] initWithFrame:CGRectMake(10.0f, 0.0f, 300.0f, 40.0f)];
slider.backgroundColor = [UIColor clearColor]; // Hintergrundfarbe ist transparent
[slider setThumbImage: [UIImage imageNamed:@"Thumb.png"] forState:UIControlStateNormal]; // der verschiebbare Thumb
[slider setMinimumTrackImage:[UIImage imageNamed:@"Left.png"] forState:UIControlStateNormal]; // linke seite vom Thumb
[slider setMaximumTrackImage:[UIImage imageNamed:@"Right.png"] forState:UIControlStateNormal]; // rechte Seite vom Thumb