前言

本来没有打算写这篇文章的, 主要是因为在工作中遇到一些同事再用 有UIButton的时候, 有些很基本的,系统API提供的都不知道, 例如 如何让UIButton的文字居上,居左, 居右, 居下对其等一些基本点, 为此我特地写了一下UIButton小结

UIButton回顾

继承关系

NSObject -> UIResponder -> UIView -> UIControl -> UIButton
复制代码

API

初始化

遍历构造器

+ (instancetype)buttonWithType:(UIButtonType)buttonType;
复制代码

button类型

 typedef NS_ENUM(NSInteger, UIButtonType) {UIButtonTypeCustom = 0,                        //自定义风格UIButtonTypeSystem NS_ENUM_AVAILABLE_IOS(7_0), //系统样式，从iOS7开始使用UIButtonTypeDetailDisclosure,                  //蓝色小箭头按钮，主要做详细说明用UIButtonTypeInfoLight,                         //亮色感叹号UIButtonTypeInfoDark,                          //暗色感叹号UIButtonTypeContactAdd,                        //十字加号按钮UIButtonTypeRoundedRect = UIButtonTypeSystem,  //圆角矩形，从iOS7废弃，iOS6中可以使用};
复制代码

偏移量

内容偏移量：正值表示间隔值，负值表示超出参照物的距离。UIEdgeInsetsMake(top, left, bottom, right)有四个值需要设置，分别距离上左下右边的间隔。

// default is UIEdgeInsetsZero. On tvOS 10 or later, default is nonzero except for custom buttons.
@property(nonatomic) UIEdgeInsets contentEdgeInsets UI_APPEARANCE_SELECTOR;
复制代码

标题偏移量：和图片偏移量是相对的，比如：自定义一个按钮实现的效果是图片在左边，标题在右边，可以用这个属性，设置完标题偏移量，图片偏移量就是相对于标题的

@property(nonatomic) UIEdgeInsets titleEdgeInsets; // default is UIEdgeInsetsZero
复制代码

图片偏移量

@property(nonatomic) UIEdgeInsets imageEdgeInsets;  
复制代码

其他API

button的状态为高亮时，文本的阴影会反转 默认是NO

@property(nonatomic) BOOL reversesTitleShadowWhenHighlighted;
复制代码

button的状态为高亮时，图像变暗 默认是YES

@property(nonatomic) BOOL adjustsImageWhenHighlighted;
复制代码

button的状态为禁用时，图像变暗。默认是YES

@property(nonatomic) BOOL adjustsImageWhenDisabled;
复制代码

button的状态为高亮时，发光。默认是NO

@property(nonatomic) BOOL showsTouchWhenHighlighted;
复制代码

系统的一些样式DetailDisclosure InfoLight InfoDark ContactAdd颜色会改变

@property(nonatomic,retain) UIColor *tintColor NS_AVAILABLE_IOS(5_0);
复制代码

button的状态。包括一些其他的控制的状态

typedef NS_OPTIONS(NSUInteger, UIControlState) {UIControlStateNormal       = 0,      //正常状态UIControlStateHighlighted  = 1 << 0, //高亮状态UIControlStateDisabled     = 1 << 1, //禁用状态UIControlStateSelected     = 1 << 2, //选中状态UIControlStateApplication  = 0x00FF0000,UIControlStateReserved     = 0xFF000000
};
复制代码

// 设置标题 default is nil. title is assumed to be single line
- (void)setTitle:(nullable NSString *)title forState:(UIControlState)state;  // 设置标题颜色 default if nil. use opaque white
- (void)setTitleColor:(nullable UIColor *)color forState:(UIControlState)state UI_APPEARANCE_SELECTOR;// 设置标题阴影颜色default is nil. use 50% black
- (void)setTitleShadowColor:(nullable UIColor *)color forState:(UIControlState)state UI_APPEARANCE_SELECTOR; // 设置图片default is nil. 
should be same size if different for different states
- (void)setImage:(nullable UIImage *)image forState:(UIControlState)state;  // 设置背景图片// default is nil
- (void)setBackgroundImage:(nullable UIImage *)image forState:(UIControlState)state UI_APPEARANCE_SELECTOR; // 设置富文本标题default is nil. title is assumed to be single line
- (void)setAttributedTitle:(nullable NSAttributedString *)title forState:(UIControlState)state NS_AVAILABLE_IOS(6_0); 
复制代码

// 返回不同状态下标题
- (nullable NSString *)titleForState:(UIControlState)state;// 返回不同状态下标题颜色
- (nullable UIColor *)titleColorForState:(UIControlState)state;// 返回不同状态下标题阴影颜色
- (nullable UIColor *)titleShadowColorForState:(UIControlState)state;// 返回不同状态下图片
- (nullable UIImage *)imageForState:(UIControlState)state;// 返回不同状态下背景图片
- (nullable UIImage *)backgroundImageForState:(UIControlState)state;// 返回不同状态下富文本标题
- (nullable NSAttributedString *)attributedTitleForState:(UIControlState)state NS_AVAILABLE_IOS(6_0);复制代码

// button的当前标题。当按钮状态改变时值自动改变，可以做判断，当前标题是全文则点击展开标题设置为收起，当前标题是收起则点击收起全文。
@property(nullable, nonatomic,readonly,strong) NSString *currentTitle;          // 当前标题颜色default is white(1,1)
@property(nonatomic,readonly,strong) UIColor  *currentTitleColor;        // 当前状态下标题阴影颜色
@property(nullable, nonatomic,readonly,strong) UIColor  *currentTitleShadowColor; 
// 当前状态下图片 切换不同图片，比如做单选，多选可以使用。
@property(nullable, nonatomic,readonly,strong) UIImage  *currentImage;             
@property(nullable, nonatomic,readonly,strong) UIImage  *currentBackgroundImage;   
@property(nullable, nonatomic,readonly,strong) NSAttributedString *currentAttributedTitle NS_AVAILABLE_IOS(6_0); 
复制代码

@property(nullable, nonatomic,readonly,strong) UILabel     *titleLabel NS_AVAILABLE_IOS(3_0);
@property(nullable, nonatomic,readonly,strong) UIImageView *imageView  NS_AVAILABLE_IOS(3_0);
复制代码

// 返回背景绘制区域
- (CGRect)backgroundRectForBounds:(CGRect)bounds;// 返回内容绘制区域。内容区域是显示图片和标题及他们特定对齐缩放等的范围
- (CGRect)contentRectForBounds:(CGRect)bounds;// 返回标题的绘制区域
- (CGRect)titleRectForContentRect:(CGRect)contentRect;// 返回图片的绘制区域
- (CGRect)imageRectForContentRect:(CGRect)contentRect;
复制代码

这个地方的API是UIControl的, 很多人并没有在意这个类, 然后用一些很笨的手段去解决对其方式

// button 内容垂直对其方式 default is center
@property(nonatomic) UIControlContentVerticalAlignment contentVerticalAlignment; // button 内容水平对其方式 default is center
@property(nonatomic) UIControlContentHorizontalAlignment contentHorizontalAlignment;
复制代码