使用NSAttributedString，添加删除线，中划线 链接

常用的是其子类：NSMutableAttributedString 加中划线，删除线的方法：

#import

- (BOOL)saveCredentials:(NSError **)error {
    SSKeychainQuery *query = [[SSKeychainQuery alloc] init];
    query.password = @"MySecretPassword";
    query.service = @"MyAwesomeService";
    query.account = @"John Doe";
    query.synchronizable = YES;
    return [query save:&error];
}

- (NSString *)savedPassword:(NSError **)error {
    SSKeychainQuery *query = [[SSKeychainQuery alloc] init];
    query.service = @"MyAwesomeService";
    query.account = @"John Doe";
    query.synchronizable = YES;
    query.password = nil;
    if ([query fetch:&error]) {
        return query.password;
    }
    return nil;
NSAttributedString *attrString; // from previous code
NSDictionary *options = @{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType};

NSData *htmlData = [attrString dataFromRange:NSMakeRange(0, [attrString length]) documentAttributes:options error:nil];
NSString *htmlString = [[NSString alloc] initWithData:htmlData encoding:NSUTF8StringEncoding];