// for (NSString *fontFamilyName in [UIFont familyNames]) {
// NSLog(@"family: \'%@\'", fontFamilyName);
// for (NSString *fontName in [UIFont fontNamesForFamilyName:fontFamilyName]) {
// NSLog(@"\tfont:\'%@\'", fontName);
// }
// NSLog(@"--------------");
// }
// family: \'PingFang SC\'
// font:\'PingFangSC-Medium\'
// font:\'PingFangSC-Semibold\'
// font:\'PingFangSC-Light\'
// font:\'PingFangSC-Ultralight\'
// font:\'PingFangSC-Regular\'
// font:\'PingFangSC-Thin\'