iOS － 用Masonry封装的slider，完全支持Masonry的适配

上一篇博主用相对高度封装了一个slider，当时其实想用Masonry的，但是发现使用的并不熟练，所以今天又对这个Demo用Masonry重新进行了封装，感觉比较难的地方在于利用约束确定中心点的位置和约束的更新，具体的请看代码：

//
//  MySlider.m
//  MySlider
//
//  Created by 刘浩浩 on 16/7/21.
//  Copyright © 2016年 CodingFire. All rights reserved.
//

#import "MySlider.h"

@interface MySlider()
{
UIView *lastView;
CGFloat currentX;
CGPoint clickCenter;
NSString *type;
}

@property(nonatomic,strong)UIView *baseView;
/**
*  slier背景
*/
@property(nonatomic,strong)UIView *preSliderView;
/**
*  slider覆盖颜色
*/
@property(nonatomic,strong)UIView *lastSliderView;
/**
*  滑块
*/
@property(nonatomic,strong)UIButton *sliderBtn;
/**
*  模糊点击区域按钮
*/
@property(nonatomic,strong)UIButton *expandBtn;

@end

@implementation MySlider

- (id)init {
self = [super init];
if (!self) return nil;

[self setSlierUI];
return self;
}

- (void)setSlierUI
{

lastView = self;
//    lastView.backgroundColor = [UIColor redColor];
_baseView = [[UIView alloc]init];
[self addSubview:_baseView];

_preSliderView = [[UIView alloc]init];
_preSliderView.layer.cornerRadius = 10;
_preSliderView.backgroundColor = [UIColor grayColor];
_preSliderView.clipsToBounds = YES;
[_baseView addSubview:_preSliderView];

_lastSliderView = [[UIView alloc]init];
_lastSliderView.backgroundColor = [UIColor blueColor];
[_preSliderView addSubview:_lastSliderView];

UITapGestureRecognizer *tapGes = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapMoving:)];
[_preSliderView addGestureRecognizer:tapGes];

_sliderBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
_sliderBtn.backgroundColor = [UIColor lightGrayColor];
if (_slImage == nil) {
_sliderBtn.layer.borderWidth = 0.5;
_sliderBtn.layer.borderColor = [UIColor grayColor].CGColor;
_sliderBtn.backgroundColor = [UIColor lightGrayColor];
}
else
{
[_sliderBtn setImage:_slImage forState:UIControlStateNormal];
}
_sliderBtn.userInteractionEnabled = YES;
_sliderBtn.layer.cornerRadius = _widthSameHeight / 2;

[_sliderBtn addTarget:self action:@selector(dragMoving:withEvent:)forControlEvents: UIControlEventTouchDragInside];
[_baseView addSubview:_sliderBtn];

_expandBtn = [UIButton buttonWithType:UIButtonTypeSystem];
_expandBtn.center = _sliderBtn.center;
[_expandBtn addTarget:self action:@selector(dragMoving:withEvent:)forControlEvents: UIControlEventTouchDragInside];
[_baseView addSubview:_expandBtn];

[_baseView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.and.top.and.right.and.bottom.equalTo(lastView);
}];

[_preSliderView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.and.right.equalTo(lastView);
make.center.equalTo(lastView);
make.height.mas_equalTo(_slHeight);
make.width.equalTo(lastView.mas_width);
}];

[_lastSliderView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.and.top.and.bottom.equalTo(_preSliderView);
make.height.equalTo(_preSliderView.mas_height);
make.width.equalTo(_preSliderView.mas_width).multipliedBy(0.5);
make.centerY.equalTo(_preSliderView.mas_centerY);
}];

[_sliderBtn mas_makeConstraints:^(MASConstraintMaker *make) {
make.centerY.equalTo(_lastSliderView);
make.width.and.height.mas_equalTo(20);
make.left.equalTo(_lastSliderView.mas_right).offset(-20 / 2);
}];

[_expandBtn mas_makeConstraints:^(MASConstraintMaker *make) {
make.centerY.equalTo(_lastSliderView);
make.left.equalTo(_lastSliderView).offset(-20);
make.width.and.height.mas_equalTo(20 * 2);
}];

}
- (void)tapMoving:(UITapGestureRecognizer *)tap
{
CGPoint point = [tap locationInView:_preSliderView];
currentX = point.x;
type = @"tap";
// 告诉self.view约束需要更新
[self setNeedsUpdateConstraints];
// 调用此方法告诉self.view检测是否需要更新约束，若需要则更新，下面添加动画效果才起作用
[self updateConstraintsIfNeeded];

[self layoutIfNeeded];

}

- (void)updateConstraints
{

if ([type isEqualToString:@"nottap"]) {

[_preSliderView mas_remakeConstraints:^(MASConstraintMaker *make) {
make.left.and.right.equalTo(lastView);
make.center.equalTo(lastView);
make.height.mas_equalTo(_slHeight);
make.width.equalTo(lastView.mas_width);
}];

[_lastSliderView mas_remakeConstraints:^(MASConstraintMaker *make) {
make.left.and.top.and.bottom.equalTo(_preSliderView);
make.height.equalTo(_preSliderView.mas_height);
make.width.equalTo(_preSliderView.mas_width).multipliedBy(_value);
make.centerY.equalTo(_preSliderView.mas_centerY);
}];

[_sliderBtn mas_remakeConstraints:^(MASConstraintMaker *make) {
make.centerY.equalTo(_lastSliderView);
make.width.and.height.mas_equalTo(_widthSameHeight);
make.left.equalTo(_lastSliderView.mas_right).offset(-_widthSameHeight / 2);
}];

[_expandBtn mas_remakeConstraints:^(MASConstraintMaker *make) {
make.centerY.equalTo(_lastSliderView);
make.width.height.mas_equalTo(_widthSameHeight * 2);
make.left.equalTo(_lastSliderView.mas_right).offset(-_widthSameHeight);

}];
}
if ([type isEqualToString:@"tap"]) {
[_lastSliderView mas_remakeConstraints:^(MASConstraintMaker *make) {
make.left.and.top.and.bottom.equalTo(_preSliderView);
make.height.equalTo(_preSliderView.mas_height);
make.width.mas_equalTo(currentX);
make.centerY.equalTo(_preSliderView.mas_centerY);
}];

[_sliderBtn mas_remakeConstraints:^(MASConstraintMaker *make) {
make.centerY.equalTo(_lastSliderView);
make.width.and.height.mas_equalTo(_widthSameHeight);
make.left.mas_equalTo(currentX - _widthSameHeight / 2);
}];

[_expandBtn mas_remakeConstraints:^(MASConstraintMaker *make) {
make.centerY.equalTo(_lastSliderView);
make.width.and.height.mas_equalTo(_widthSameHeight * 2);
make.left.mas_equalTo(currentX - _widthSameHeight * 2 / 2);

}];
}

[super updateConstraints];
}

- (void)dragMoving: (UIButton *)btn withEvent:(UIEvent *)event
{
CGPoint point = [[[event allTouches] anyObject] locationInView:self];

CGFloat x = point.x;

if(x <= _widthSameHeight / 2)

{
point.x = _widthSameHeight / 2;
}

if(x >= self.bounds.size.width - _widthSameHeight / 2)

{

point.x = self.bounds.size.width - _widthSameHeight / 2;

}

point.y = self.frame.size.height / 2;

currentX = point.x;

type = @"tap";

// 告诉self.view约束需要更新
[self setNeedsUpdateConstraints];
// 调用此方法告诉self.view检测是否需要更新约束，若需要则更新，下面添加动画效果才起作用
[self updateConstraintsIfNeeded];

[self layoutIfNeeded];

}

- (void)setValue:(CGFloat)value
{
_value = value;
type = @"nottap";

// 告诉self.view约束需要更新
[self setNeedsUpdateConstraints];
// 调用此方法告诉self.view检测是否需要更新约束，若需要则更新，下面添加动画效果才起作用
[self updateConstraintsIfNeeded];

[self layoutIfNeeded];

}

- (void)setSlImage:(UIImage *)slImage
{
_slImage = slImage;
[_sliderBtn setImage:_slImage forState:UIControlStateNormal];
}

- (void)setSlHeight:(CGFloat)slHeight
{
_slHeight = slHeight;
if (_slHeight >= 2 && _slHeight <= 20) {
type = @"nottap";
// 告诉self.view约束需要更新
[self setNeedsUpdateConstraints];
// 调用此方法告诉self.view检测是否需要更新约束，若需要则更新，下面添加动画效果才起作用
[self updateConstraintsIfNeeded];

[self layoutIfNeeded];

}
}

- (void)setPreBackgroundColor:(UIColor *)preBackgroundColor
{
_preBackgroundColor = preBackgroundColor;
_preSliderView.backgroundColor = _preBackgroundColor;
}

- (void)setLastBackgroundColor:(UIColor *)lastBackgroundColor
{
_lastBackgroundColor = lastBackgroundColor;
_lastSliderView.backgroundColor = _lastBackgroundColor;

}

- (void)setWidthSameHeight:(CGFloat)widthSameHeight
{
_widthSameHeight = widthSameHeight;

type = @"nottap";

_sliderBtn.layer.cornerRadius = _widthSameHeight / 2;

// 告诉self.view约束需要更新
[self setNeedsUpdateConstraints];
// 调用此方法告诉self.view检测是否需要更新约束，若需要则更新，下面添加动画效果才起作用
[self updateConstraintsIfNeeded];

[self layoutIfNeeded];

}

- (void)setSliderBackgroundColor:(UIColor *)sliderBackgroundColor
{
_sliderBackgroundColor = sliderBackgroundColor;
_sliderBtn.backgroundColor = _sliderBackgroundColor;
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
// Drawing code
}
*/

@end

加约束并没有想象的那么简单，只有真正动手去做了才知道其中的易错点，但是使用熟练了确实蛮方便的，对这里的约束有什么不懂的请留言或者自行百度。

Demo下载地址：https://github.com/codeliu6572/MySlider