Objective C Printing:如何设置标题内容？

#import <UIKit/UIKit.h>

@property (strong, nonatomic) UILabel *titleLabel;

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // 初始化标题标签
    self.titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 40)];
    
    // 设置标题标签的属性
    self.titleLabel.text = @"标题内容";
    self.titleLabel.textColor = [UIColor whiteColor];
    self.titleLabel.textAlignment = NSTextAlignmentCenter;
    self.titleLabel.font = [UIFont systemFontOfSize:18];
    
    // 将标题标签添加到导航栏中
    self.navigationItem.titleView = self.titleLabel;
}