在写项目时，发现在非刘海屏型号的iPhone上测试的UI界面，有时候在刘海屏iPhone会被遮挡。这时候，我们需要判断当前设备是否是刘海屏，以来对UI代码做相应的适配，以下是学习的几种方案。
判断手机型号
iPhone的发展历史中，手机屏幕从来不是一尘不变的。从home键非全面屏到取消home键刘海屏，苹果公司一直在屏幕上做改变。并且不只是屏幕，耳机孔、按键等也在不断发生变化。所以在目标机型是所有iPhone的iOS开发中，判断手机型号是必要的。下面是判断手机型号的步骤。
引入头文件，声明类方法
#import <UIKit/UIKit.h>
#import <sys/utsname.h>@interface ViewController : UIViewController+ (NSString*)judgeIphoneType;@end
实现类方法
+ (NSString*)judgeIphoneType {struct utsname systemInfo;uname(&systemInfo);NSString * phoneType = [NSString stringWithCString: systemInfo.machine encoding:NSASCIIStringEncoding];// simulator 模拟器if ([phoneType isEqualToString:@"i386"]) {return @"Simulator";}if ([phoneType isEqualToString:@"x86_64"]) {return @"Simulator";}// 常用机型 不需要的可自行删除if([phoneType isEqualToString:@"iPhone1,1"]) {return @"iPhone 2G";}if([phoneType isEqualToString:@"iPhone1,2"]) {return @"iPhone 3G";}if([phoneType isEqualToString:@"iPhone2,1"]) {return @"iPhone 3GS";}if([phoneType isEqualToString:@"iPhone3,1"]) {return @"iPhone 4";}if([phoneType isEqualToString:@"iPhone3,2"]) {return @"iPhone 4";}if([phoneType isEqualToString:@"iPhone3,3"]) {return @"iPhone 4";}if([phoneType isEqualToString:@"iPhone4,1"]) {return @"iPhone 4S";}if([phoneType isEqualToString:@"iPhone5,1"]) {return @"iPhone 5";}if([phoneType isEqualToString:@"iPhone5,2"]) {return @"iPhone 5";}if([phoneType isEqualToString:@"iPhone5,3"]) {return @"iPhone 5c";}if([phoneType isEqualToString:@"iPhone5,4"]) {return @"iPhone 5c";}if([phoneType isEqualToString:@"iPhone6,1"]) {return @"iPhone 5s";}if([phoneType isEqualToString:@"iPhone6,2"]) {return @"iPhone 5s";}if([phoneType isEqualToString:@"iPhone7,1"]) {return @"iPhone 6 Plus";}if([phoneType isEqualToString:@"iPhone7,2"]) {return @"iPhone 6";}if([phoneType isEqualToString:@"iPhone8,1"]) {return @"iPhone 6s";}if([phoneType isEqualToString:@"iPhone8,2"]) {return @"iPhone 6s Plus";}if([phoneType isEqualToString:@"iPhone8,4"]) {return @"iPhone SE";}if([phoneType isEqualToString:@"iPhone9,1"]) {return @"iPhone 7";}if([phoneType isEqualToString:@"iPhone9,2"]) {return @"iPhone 7 Plus";}if([phoneType isEqualToString:@"iPhone10,1"]) {return @"iPhone 8";}if([phoneType isEqualToString:@"iPhone10,4"]) {return @"iPhone 8";}if([phoneType isEqualToString:@"iPhone10,2"]) {return @"iPhone 8 Plus";}if([phoneType isEqualToString:@"iPhone10,5"]) {return @"iPhone 8 Plus";}if([phoneType isEqualToString:@"iPhone10,3"]) {return @"iPhone X";}if([phoneType isEqualToString:@"iPhone10,6"]) {return @"iPhone X";}if([phoneType isEqualToString:@"iPhone11,8"]) {return @"iPhone XR";}if([phoneType isEqualToString:@"iPhone11,2"]) {return @"iPhone XS";}if([phoneType isEqualToString:@"iPhone11,4"]) {return @"iPhone XS Max";}if([phoneType isEqualToString:@"iPhone11,6"]) {return @"iPhone XS Max";}if([phoneType isEqualToString:@"iPhone12,1"]) {return @"iPhone 11";}if ([phoneType isEqualToString:@"iPhone12,3"]) {return @"iPhone 11 Pro";}if ([phoneType isEqualToString:@"iPhone12,5"]) {return @"iPhone 11 Pro Max";}if ([phoneType isEqualToString:@"iPhone12,8"]) {return @"iPhone SE2";}if ([phoneType isEqualToString:@"iPhone13,1"]) {return @"iPhone 12 mini";}if ([phoneType isEqualToString:@"iPhone13,2"]) {return @"iPhone 12";}if ([phoneType isEqualToString:@"iPhone13,3"]) {return @"iPhone 12 Pro";}if ([phoneType isEqualToString:@"iPhone13,4"]) {return @"iPhone 12 Pro Max";}if ([phoneType isEqualToString:@"iPhone14,4"]) {return @"iPhone 13 mini";}if ([phoneType isEqualToString:@"iPhone14,5"]) {return @"iPhone 13";}if ([phoneType isEqualToString:@"iPhone14,2"]) {return @"iPhone 13 Pro";}if ([phoneType isEqualToString:@"iPhone14,3"]) {return @"iPhone 13 Pro Max";}return phoneType;}
关于iPhone的phoneType，在网站 theiphonewiki 可以查到。
通过当前视图的 Safe Area 位置判断
因为iPhone X外形与往代iPhone的变化，iOS 11 中引入了 Safe Area （安全区）这个概念，并且建议我们不要把任何交互放在 Safe Area 之外。
利用 Safe Area，我们可以简单的判断当前机型是否是刘海屏。
if (UIApplication.sharedApplication.keyWindow.safeAreaInsets.top > 20) {NSLog(@"是刘海屏");
} else {NSLog(@"不是刘海屏");
}
通过状态栏高度判断
通过状态栏高度判断是否是刘海屏，与通过 Safe Area 判断差不多。但它的好处是不用调用keyWindow，在SDK开发中更广适。
if ([[UIApplication sharedApplication] statusBarFrame].size.height > 20) {NSLog(@"是刘海屏");
}else{NSLog(@"不是刘海屏");
}
