初始化控件
UIStepper *step = [UIStepper alloc] initWithFram:(CGrectMake(100,100,200,50))];
设置控制器值是否连续触发变化
@property(nonatomic,getter = isContinuous) BOOL continuous;
若设置为YES,则长按会连续触发变化，若为NO，只有在按键结束后，才会触发。
设置长按是否一直触发变化
@property(nonatomic) BOOL autorepeat;
若设置为YES，则长按会一直发生改变，若为NO，则一次点击只会改变一次值
设置控制器的值是否循环（到达边界后，重头开始，默认为NO）
@property(nonatomic) BOOL wraps;
设置控制器的值
@property(nonatomic) double value;
设置控制器的最大值和最小值
@property(nonatomic) double minimumValue;//默认为0
@property(nonatomic) double maximumValue;//默认为100
设置控制器的步长
@property(nonatomic) double stepValue;
设置控时器风格背景图片
-(void)setBackgroundImage:(UIImage *) image forState:(UIControlState)state;
获取背景图片
-(UIImage *)BackgroundImageForState:(UIControlState)state;
通过左右按钮的状态设置分割线的图片
- (void)setDividerImage:(UIImage*)image forLeftSegmentState:(UIControlState)leftState rightSegmentState:(UIControlState)rightState;
获取分割线图片
- (UIImage*)dividerImageForLeftSegmentState:(UIControlState)state rightSegmentState:(UIControlState)state;
设置和获取加号按钮的图片
- (void)setIncrementImage:(UIImage *)image forState:(UIControlState)state;
- (UIImage *)incrementImageForState:(UIControlState)state;
设置和获取减号按钮的图片
- (void)setDecrementImage:(UIImage *)image forState:(UIControlState)state;
- (UIImage *)decrementImageForState:(UIControlState)state;