iOS修改UISlider滑块大小

原理：使用图更换滑块。进而修改图片的大小来修改滑块的大小，然后给图添加阴影效果

.m文件

#import "HWSlider.h"

#define kSliderHeight   10//slider高

@interface HWSlider ()

/// 是否设置过layer

@property (nonatomic , readwrite , assign) BOOL didSetLayer;

@end

@implementation HWSlider

- (instancetype)initWithFrame:(CGRect)frame{

    if(self= [superinitWithFrame:frame]) {

        [self setThumbImage:[UIImage imageNamed:@"圆"] forState:UIControlStateNormal];//通过直接修改图片的大小

    }

    return self;

}

/// 设置track（滑条）尺寸

- (CGRect)trackRectForBounds:(CGRect)bounds{

    returnCGRectMake(0, (bounds.size.height-kSliderHeight) /2.0, bounds.size.width,kSliderHeight);//滑杆高改为10

}

#pragma mark- 布局

- (void)layoutSubviews{

    [super layoutSubviews];

    if (self.didSetLayer) {

        return;

    }

    BOOLdidSetLayer =NO;

    for(UIView*vinself.subviews) {

        if ([v isKindOfClass:[UIImageView class]] && v.frame.size.height != kSliderHeight) {//给滑块图片添加阴影

            v.layer.shadowColor = [UIColor blackColor].CGColor;

            v.layer.shadowOffset = CGSizeMake(1, 1);

            v.layer.shadowOpacity=0.5;

            didSetLayer =YES;

        }

    }

    self.didSetLayer= didSetLayer;

}

@end