UIButton

首先需要说明UIButton继承自UIControl，UIControl继承自UIView

• 常用属性

  • 调整titleLabel和imageView的相对位置

    1.
    2.@property (nonatomic) UIEdgeInsets titleEdgeInsets;
    3.@property (nonatomic) UIEdgeInsets imageEdgeInsets;
    

  • titleLabel和imageView

    1.@property (nonatomic,readonly,strong) UILabel *titleLabel;
    2.@property (nonatomic,readonly,strong) UIImageView *imageView;
    

  • 需要注意的是：修改title的字体大小

    1.button.titleLabel.font = [UIFont systemFontOfSize:14.0f];
    

  ---

• 继承自UIControl的属性

  1.@property(nonatomic,getter=isEnabled) BOOL enabled;                                  // default is YES. if NO, ignores touch events and subclasses may draw differently
  2.@property(nonatomic,getter=isSelected) BOOL selected;                                
  3.// default is NO.
  4.@property(nonatomic,getter=isHighlighted) BOOL highlighted; 
  5.// default is NO.
  6.@property(nonatomic,readonly) UIControlState state; 
  

• 常用方法

  • 设置title
    - (void)setTitle:(nullable NSString *)title forState:(UIControlState)state;
  • 设置title颜色
    - (void)setTitleColor:(nullable UIColor *)color forState:(UIControlState)state
  • 设置image
    - (void)setImage:(nullable UIImage *)image forState:(UIControlState)state;
  • 设置背景图
    - (void)setBackgroundImage:(nullable UIImage *)image forState:(UIControlState)state
  • 设置富文本title
    - (void)setAttributedTitle:(nullable NSAttributedString *)title forState:(UIControlState)state
  • 子类调整imageView和titleLabel的位置可重写下面方法
    

    1.
    2.- (CGRect)titleRectForContentRect:(CGRect)contentRect;
    3.- (CGRect)imageRectForContentRect:(CGRect)contentRect;
    4.
    

• 继承自UIControl的方法
  
  • 添加监听
    - (void)addTarget:(nullable id)target action:(SEL)action forControlEvents:(UIControlEvents)controlEvents;
  • 移除监听
    - (void)removeTarget:(nullable id)target action:(nullable SEL)action forControlEvents:(UIControlEvents)controlEvents;

• 示例：展示调整titleLabel 和 imageView 位置，默认是图片在左，文字在右。但是在此，我想让图片在上，文字在下。

  • 默认样式
    
  • 调整后
    
  • 代码
    

    1.
    2.button.titleEdgeInsets = UIEdgeInsetsMake(100, -100, 0, 0);
    3.button.imageEdgeInsets = UIEdgeInsetsMake(0, 20, 0, 0);
    4.