判断型号
#import <sys/utsname.h>
struct utsname systemInfo;
uname(&systemInfo);
NSString * phoneType = [NSString stringWithCString: systemInfo.machine encoding:NSASCIIStringEncoding];
if ([phoneType isEqualToString:@"iPhone12,8"]) return @"iPhone SE2";
来源参考：https://stackoverflow.com/questions/26028918/how-to-determine-the-current-iphone-device-model
设计规范
SE2的UI设计规范可以参考 iPhone 8
设计参考规范： http://www.xueui.cn/design/142395.html