iOS 导航栏颜色字体等的自定义

1.设置导航栏中间文字的文字颜色和文字大小

方法一：系统方法

self.title = @"下载微课";//在有navigationController的控制器中，作用与self.navigationItem.title = @"下载微课";相同
[self.navigationController.navigationBar setTitleTextAttributes:
  @{NSFontAttributeName:[UIFont systemFontOfSize:18],
    NSForegroundColorAttributeName:[UIColor whiteColor]}];//系统方法

 方法二：自定义控件

self.navigationItem.title = @"下载微课";
//修改导航栏
UILabel *titleLable = [[UILabel alloc]initWithFrame:CGRectMake(0,0,100,30)];
titleLable.text = @"下载微课";
titleLable.textColor = [UIColor whiteColor];
titleLable.font = [UIFont systemFontOfSize:18];
self.navigationItem.titleView = titleLable;

 效果图：

2.设置返回键的颜色和样式