在导航栏添加搜索框

    //导航条的搜索条
        UISearchBar *searchBar = [[UISearchBar alloc]initWithFrame:CGRectMake(500.0f,0.0f,250.0f,44.0f)];
         = self;
        [searchBar setPlaceholder:@ "搜索" ];

        //将搜索条放在一个UIView上
        UIView *searchView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 768, 44)];
         = [UIColor clearColor];
        [searchView addSubview:searchBar];

         = searchView;

      
// 自定义导航栏的背景：
[[UINavigationBar appearance] setBarTintColor:[UIColor redColor]];   //@{}代表Dictionary   

 [[UINavigationBar appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor whiteColor]}];