UIButtonType各个类型的解释:

UIButtonType各个类型的解释:

typedef NS_ENUM(NSInteger, UIButtonType) {
    UIButtonTypeCustom = ,
    UIButtonTypeSystem,
    UIButtonTypeDetailDisclosure,
    UIButtonTypeInfoLight,
    UIButtonTypeInfoDark,
    UIButtonTypeContactAdd,
    UIButtonTypePlain,
    UIButtonTypeRoundedRect = UIButtonTypeSystem
};

• UIButtonTypeCustom：
  官方：No button style.
  解释：自定义的按钮（无样式）

• UIButtonTypeSystem：
  官方：A system style button, such as those shown in navigation bars and toolbars.
  解释：系统样式

• UIButtonTypeDetailDisclosure：
  官方： A detail disclosure button.
  解释：细节详情样式

• UIButtonTypeInfoLight：
  官方：An information button that has a light background.
  解释：按钮图片为i字母（info）亮的信息类型

• UIButtonTypeInfoDark：
  官方：An information button that has a dark background.
  解释：按钮图片为i字母（info）暗的信息类型

注意： iOS7及之后，只有在设置showsTouchWhenHighlighted为YES的时候，DetailDisclosure的外观和InfoLight/InfoDark不同(测试的时候我并没有看出来什么不同，如果你看出来了，劳烦告诉我)，其他情况下都相同

• UIButtonTypeContactAdd：
  官方：A contact add button.
  解释：加号（➕）按钮类型

• UIButtonTypePlain：
  官方：A standard system button without a blurred background view.
  解释：没有模糊背景视图的标准的系统按钮 不过只支持 tvOS

• UIButtonTypeRoundedRect = UIButtonTypeSystem：
  官方：A rounded-rectangle style button.
  解释：方形的圆角形式的按钮，在iOS7后被废弃，现在需要使用border的方式来做到效果
  注意：（UIButtonTypeRoundedRect已废弃， UIButtonTypeRoundedRect的枚举值为1 ！

相关代码

#import "QiButton_ButtonTypeViewController.h"

@interface QiButton_ButtonTypeViewController ()
@end

@implementation QiButton_ButtonTypeViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.title = @"UIButtonType";
    [self buttonType];
}

#pragma mark - Private functions
- (void)buttonType {
    NSArray <NSString *>*buttonTypes = @[@"UIButtonTypeCustom",
                                         @"UIButtonTypeSystem NS_ENUM_AVAILABLE_IOS(7_0)",
                                         @"UIButtonTypeDetailDisclosure",
                                         @"UIButtonTypeInfoLight",
                                         @"UIButtonTypeInfoDark",
                                         @"UIButtonTypeContactAdd",
                                         @"UIButtonTypePlain API_AVAILABLE(tvos(11.0)) API_UNAVAILABLE(ios, watchos)",
                                         @"7 = UIButtonTypePlain | UIButtonTypeSystem",
                                         @"UIButtonTypeRoundedRect = UIButtonTypeSystem",
                                         @"new a Button"];
    CGFloat btnHeight = [UIScreen mainScreen].bounds.size.height / buttonTypes.count;

    for (NSInteger buttonTypeI =  ; buttonTypeI < buttonTypes.count; buttonTypeI ++) {
        UIButton *buttonTypeBtn = [UIButton buttonWithType:buttonTypeI];
        // 设置最后的一个按钮 new的方式创建
        if (buttonTypeI == buttonTypes.count - ) {
            // 经测试 打印的btn.buttonType 为 UIButtonTypeCustom 观察button的显示样式也是如此
            buttonTypeBtn = [UIButton new];
            [buttonTypeBtn setImage:[UIImage imageNamed:@"smallQiShareLogo"] forState:UIControlStateNormal];
            [buttonTypeBtn setImage:[UIImage imageNamed:@"smallQiShareLogo"] forState:UIControlStateHighlighted];
        } else if(buttonTypeI == buttonTypes.count - ) {
            /** 注意UIButtonTypeRoundedRect = UIButtonTypeSystem 真正的值为 1 而不是7
                如果以 [UIButton buttonWithType:7] 方式创建UIButton
                相当于 [UIButton buttonWithType:UIButtonTypePlain | UIButtonTypeSystem];
             */
            buttonTypeBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
            [buttonTypeBtn setImage:[UIImage imageNamed:@"smallQiShareLogo"] forState:UIControlStateNormal];
            [buttonTypeBtn setImage:[UIImage imageNamed:@"smallQiShareLogo"] forState:UIControlStateHighlighted];
        } else if(buttonTypeI == UIButtonTypeCustom || buttonTypeI == UIButtonTypeSystem || buttonTypeI == UIButtonTypeRoundedRect) {
            [buttonTypeBtn setImage:[UIImage imageNamed:@"smallQiShareLogo"] forState:UIControlStateNormal];
            [buttonTypeBtn setImage:[UIImage imageNamed:@"smallQiShareLogo"] forState:UIControlStateHighlighted];
        } else if(buttonTypeI == UIButtonTypeDetailDisclosure || buttonTypeI == UIButtonTypeInfoLight || buttonTypeI == UIButtonTypeInfoDark) {
            buttonTypeBtn.showsTouchWhenHighlighted = YES;
        }
        [self.view addSubview:buttonTypeBtn];
        buttonTypeBtn.frame = CGRectMake(., buttonTypeI * btnHeight, CGRectGetWidth(self.view.frame), btnHeight);
        buttonTypeBtn.backgroundColor = (buttonTypeI %  ? [UIColor lightGrayColor] : [UIColor colorWithWhite:0.8 alpha:0.8]);
        [buttonTypeBtn setTitle:buttonTypes[buttonTypeI] forState:UIControlStateNormal];
        buttonTypeBtn.titleLabel.numberOfLines = ;

        [buttonTypeBtn addTarget:self action:@selector(buttonTypeButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
    }
}

#pragma mark - Action functions

- (void)buttonTypeButtonClicked:(UIButton *)sender {
    sender.selected = !sender.selected;
}

@end