一、简介
- UIButton按钮是IOS开发中最常用的控件，作为IOS基础学习教程知识 ，初学者需要了解其基本定义和常用设置，以便在开发中熟练运用。
- UIButton类继承自UIControl类，可以通过点击实现程序与用户之间的交互。
二、关于UIButton的苹果官方API的解释
一、一些基本属性
NS_ASSUME_NONNULL_BEGIN
@class UIImage, UIFont, UIColor, UIImageView, UILabel;
按钮的枚举
typedef NS_ENUM(NSInteger, UIButtonType) {
UIButtonTypeCustom = 0, // no button type
UIButtonTypeSystem NS_ENUM_AVAILABLE_IOS(7_0), // standard system button
UIButtonTypeDetailDisclosure,
UIButtonTypeInfoLight,
UIButtonTypeInfoDark,
UIButtonTypeContactAdd,
UIButtonTypeRoundedRect = UIButtonTypeSystem, // Deprecated, use UIButtonTypeSystem instead 这个方法已经废弃，用 UIButtonTypeSystem替代
};
NS_CLASS_AVAILABLE_IOS(2_0) @interface UIButton : UIControl <NSCoding>
+ (instancetype)buttonWithType:(UIButtonType)buttonType; 单例创建按钮
@property(nonatomic) UIEdgeInsets contentEdgeInsets UI_APPEARANCE_SELECTOR; // default is UIEdgeInsetsZero 整个内容的内边距
@property(nonatomic) UIEdgeInsets titleEdgeInsets; // default is UIEdgeInsetsZero 标题的内边距
@property(nonatomic) BOOL reversesTitleShadowWhenHighlighted; // default is NO. if YES, shadow reverses to shift between engrave and emboss appearance
@property(nonatomic) UIEdgeInsets imageEdgeInsets; // default is UIEdgeInsetsZero 图片的内边距
@property(nonatomic) BOOL adjustsImageWhenHighlighted; // default is YES. if YES, image is drawn darker when highlighted(pressed) 高亮状态点击图片变暗
@property(nonatomic) BOOL adjustsImageWhenDisabled; // default is YES. if YES, image is drawn lighter when disabled 禁用状态变灰
@property(nonatomic) BOOL showsTouchWhenHighlighted __TVOS_PROHIBITED; // default is NO. if YES, show a simple feedback (currently a glow) while highlighted
@property(null_resettable, nonatomic,strong) UIColor *tintColor NS_AVAILABLE_IOS(5_0); // The tintColor is inherited through the superview hierarchy. See UIView for more information.
@property(nonatomic,readonly) UIButtonType buttonType;
二、给不同状态设置图片，标题，标题颜色，背景图片，背景阴影颜色
// you can set the image, title color, title shadow color, and background image to use for each state. you can specify data
// for a combined state by using the flags added together. in general, you should specify a value for the normal state to be used
// by other states which don't have a custom value set
- 你可以同时给不同的状态指定值。一般来说，在其他状态没有一个定制的值时，你应该为正常状态指定一个值
- (void)setTitle:(nullable NSString *)title forState:(UIControlState)state; // default is nil. title is assumed to be single line 设置标题
- (void)setTitleColor:(nullable UIColor *)color forState:(UIControlState)state UI_APPEARANCE_SELECTOR; // default if nil. use opaque white 设置标题颜色
- (void)setTitleShadowColor:(nullable UIColor *)color forState:(UIControlState)state UI_APPEARANCE_SELECTOR; // default is nil. use 50% black 设置标题阴影颜色
- (void)setImage:(nullable UIImage *)image forState:(UIControlState)state; // default is nil. should be same size if different for different states 设置图片
- (void)setBackgroundImage:(nullable UIImage *)image forState:(UIControlState)state UI_APPEARANCE_SELECTOR; // default is nil 设置背景图片
- (void)setAttributedTitle:(nullable NSAttributedString *)title forState:(UIControlState)state NS_AVAILABLE_IOS(6_0); // default is nil. title is assumed to be single line 设置富文本标题
// these getters only take a single state value 以下这些getters返回特定状态的值，返回值与上面的方法相对应
- (nullable NSString *)titleForState:(UIControlState)state;
- (nullable UIColor *)titleColorForState:(UIControlState)state;
- (nullable UIColor *)titleShadowColorForState:(UIControlState)state;
- (nullable UIImage *)imageForState:(UIControlState)state;
- (nullable UIImage *)backgroundImageForState:(UIControlState)state;
- (nullable NSAttributedString *)attributedTitleForState:(UIControlState)state NS_AVAILABLE_IOS(6_0);
三、其他状态缺少设置是可以使用正常状态的值，简称缺省使用normal的值
// these are the values that will be used for the current state. you can also use these for overrides. a heuristic will be used to
// determine what image to choose based on the explict states set. For example, the 'normal' state value will be used for all states
// that don't have their own image defined.
@property(nullable, nonatomic,readonly,strong) NSString *currentTitle; // normal/highlighted/selected/disabled. can return nil
@property(nonatomic,readonly,strong) UIColor *currentTitleColor; // normal/highlighted/selected/disabled. always returns non-nil. default is white(1,1)
@property(nullable, nonatomic,readonly,strong) UIColor *currentTitleShadowColor; // normal/highlighted/selected/disabled.
@property(nullable, nonatomic,readonly,strong) UIImage *currentImage; // normal/highlighted/selected/disabled. can return nil
@property(nullable, nonatomic,readonly,strong) UIImage *currentBackgroundImage; // normal/highlighted/selected/disabled. can return nil
@property(nullable, nonatomic,readonly,strong) NSAttributedString *currentAttributedTitle NS_AVAILABLE_IOS(6_0); // normal/highlighted/selected/disabled. can return nil
四、return title and image views.
// return title and image views. will always create them if necessary. always returns nil for system buttons
@property(nullable, nonatomic,readonly,strong) UILabel *titleLabel NS_AVAILABLE_IOS(3_0);
@property(nullable, nonatomic,readonly,strong) UIImageView *imageView NS_AVAILABLE_IOS(3_0);
五、返回大小，范围
// these return the rectangle for the background (assumes bounds), the content (image + title) and for the image and title separately. the content rect is calculated based
// on the title and image size and padding and then adjusted based on the control content alignment. there are no draw methods since the contents
// are rendered in separate subviews (UIImageView, UILabel)
- (CGRect)backgroundRectForBounds:(CGRect)bounds;
- (CGRect)contentRectForBounds:(CGRect)bounds;
- (CGRect)titleRectForContentRect:(CGRect)contentRect;
- (CGRect)imageRectForContentRect:(CGRect)contentRect;
@end
六、已经废弃不用的
@interface UIButton(UIButtonDeprecated)
@property(nonatomic,strong) UIFont *font NS_DEPRECATED_IOS(2_0, 3_0) __TVOS_PROHIBITED;
@property(nonatomic) NSLineBreakMode lineBreakMode NS_DEPRECATED_IOS(2_0, 3_0) __TVOS_PROHIBITED;
@property(nonatomic) CGSize titleShadowOffset NS_DEPRECATED_IOS(2_0, 3_0) __TVOS_PROHIBITED;
@end
NS_ASSUME_NONNULL_END
三、代码例子
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.view.backgroundColor = [UIColor whiteColor];
[self createButton];
}
- (void)createButton{
// 1.UIButton的实例化
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
/* 能够定义的button类型有以下7种，
typedef enum {
UIButtonTypeCustom = 0, 自定义风格 无样式, 最常用
UIButtonTypeRoundedRect = UIButtonTypeSystem //圆角矩形
UIButtonTypeSystem // 可以正常的显示内容, 但是, 不方便自定义
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
} UIButtonType;
*/
// 2.设置UIButton的大小
button.frame = CGRectMake(50, 100, 200, 100);
// 3. 设置边框
button.layer.borderColor = [UIColor grayColor].CGColor;
button.layer.borderWidth = 0.5f;
// 4. 绘制圆角
button.layer.cornerRadius = 5.f;
button.layer.masksToBounds = YES;
// 5. 背景颜色
button.backgroundColor = [UIColor redColor];
// 6.设置button标题和标题颜色
[button setTitle:@"点我啊!" forState:UIControlStateNormal];
[button setTitleColor:[UIColor yellowColor] forState:UIControlStateNormal];
/* forState: 这个参数的作用是定义按钮的文字或图片在何种状态下才会显现
UIControlStateNormal = 0, 常规状态显现// 正常状态, 不对button做任何的操作
UIControlStateHighlighted = 1 << 0, 高亮状态显现 点下去不是高亮, 而是正常状态(理解)
UIControlStateDisabled = 1 << 1, 禁用的状态才会显现
UIControlStateSelected = 1 << 2, 选中状态
UIControlStateApplication = 0x00FF0000, 当应用程序标志时
UIControlStateReserved = 0xFF000000 为内部框架预留，可以不管
};
*/
// 禁用状态需要设置
button.enabled = YES; //是否禁用
// 设置选中状态
button.selected = NO;// 是否选中
/*
@property(nonatomic,getter=isEnabled)BOOL enabled; // default is YES. if NO, ignores touch events and subclasses may draw differently
@property(nonatomic,getter=isSelected)BOOL selected; // default is NO may be used by some subclasses or by application
@property(nonatomic,getter=isHighlighted)BOOL highlighted;
*/
// 如果没有设置高亮,禁用... 其他状态的标题, 标题颜色, 背景图片, 标题图片 缺省使用正常状态的
// 7. 设置标题的字体
button.titleLabel.font = [UIFont boldSystemFontOfSize:30];
// 8.设置button填充图片和背景图片
// UIImage 是一个用来加载图片图片类，而UIImageView是在界面上显示图片的一个控件。在UIImageView中显示图片的话应该首先把图片加载到UIImage中，然后通过其他方式使用该UIImage。以下说明了四种常用的加载UIImage的方法：
//imageNamed:使用应用程序束中的一个文件来创建，IOS4以后的版本中可以省略图片扩展名；
//imageWithCGImage:使用Quartz 2D对象创建UIImage，与initWithCGImage等效；
// imageWithContentsOfFile：根据指定的路径创建UIImage，与initWithContentOfFile等效；
// imageWithData：使用NSData创建，与initWithData等效；
// 设置button的背景图片
[button setBackgroundImage:[UIImage imageNamed:@"logo"] forState:UIControlStateNormal];
// 设置button的标题图片，标题图片会跟随着标题整体居中
[button setImage:[UIImage imageNamed:@"logo"] forState:UIControlStateNormal];
/*9.
* 默认情况下，当按钮高亮的情况下，图像的颜色会被画深一点，如果这下面的这个属性设置为no，
* 那么可以去掉这个功能
*/
button.adjustsImageWhenHighlighted = NO;
/*跟上面的情况一样，默认情况下，当按钮禁用的时候，图像会被画得深一点，设置NO可以取消设置*/
button.adjustsImageWhenDisabled = NO;
/* 下面的这个属性设置为yes的状态下，按钮按下会发光*/
button.showsTouchWhenHighlighted = YES;
// 10.设置按钮内部图片间距和标题间距
button.contentEdgeInsets = UIEdgeInsetsMake(10, 10, 10, 10);
// 标题间距
[button setTitleEdgeInsets:UIEdgeInsetsMake(0, 0, 0, 0)
];
// 11.给button注册事件（Target - action 目标动作机制 ）
/*
target: 接收消息的对象 （目标）
action: 发送的消息, 如果方法需要参数, 参数类型必须是UIButton
controlEvent: 触发条件
UIControlEventTouchDown // 点下去(不用松手)
UIControlEventTouchDownRepeat // 重复点击(需要快速点击触发)
UIControlEventTouchDragInside // 在内部拖动
UIControlEventTouchDragOutside // 在外部拖动
UIControlEventTouchDragEnter // 拖动进入button
UIControlEventTouchDragExit // 拖动离开button
// 这个条件, 符合用户习惯, 最常使用
UIControlEventTouchUpInside // 点击button, 在内部松开
UIControlEventTouchUpOutside // 点击button, 在外部松开
UIControlEventTouchCancel // 点击取消, 无法模拟
*/
[button addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];
// self performSelector:SE withObject:self
[self.view addSubview:button];
}
- (void)buttonAction:(UIButton *)button {
// 打印button的标题
NSString *title = [button titleForState:UIControlStateNormal];
NSLog(@"%@", title);
}
博主的话
以前看过很多别人的博客，学到不少东西。现在准备自己也开始写写博客，希望能够帮到一些人。