iOS开发UI篇--UIButton

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);

}

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