iOS UI NavigationController UINavigationBar UINavigationItem

大家做一些App应用时，很多时候会用到UINavigationController。下面我简单谈谈，欢迎指正：

1.使用UINavigationController：

<p class="p1"><span class="s1">ViewController</span><span class="s2"> *vc=[[</span><span class="s1">ViewController</span><span class="s2"> </span><span class="s3">alloc</span><span class="s2">]</span><span class="s3">init</span><span class="s2">];</span></p><p class="p2"><span class="s1">UINavigationController</span><span class="s2"> *navVc=[[</span><span class="s1">UINavigationController</span><span class="s2"> </span><span class="s3">alloc</span><span class="s2">]</span><span class="s3">initWithRootViewController</span><span class="s2">:vc];</span></p><p class="p2"><span class="s4">self</span><span class="s2">.</span><span class="s5">window</span><span class="s2">.</span><span class="s1">rootViewController</span><span class="s2">=navVc;</span></p>

跳转到下一个控制器：<p class="p1"><span class="s1">[</span><span class="s2">self</span><span class="s1">.navigationController pushViewController:下一个控制器 animated:</span><span class="s2">YES</span><span class="s1">];</span></p>

2.自定义UINavigationController，用于整个项目界面风格的统一控制

//设置导航栏的主题
+(void)setupNavBarTheme
{
  
    //1.去除apperance对象
    UINavigationBar *navBar=[UINavigationBar appearance];
    navBar.tintColor = [UIColor whiteColor];
    [navBar setBarTintColor:[UIColor blackColor]];
    navBar.translucent = YES;
   
    //2.设置标题属性
    NSMutableDictionary *textAttrs=[NSMutableDictionary dictionary];
    textAttrs[NSForegroundColorAttributeName]=[UIColor whiteColor];
    textAttrs[NSFontAttributeName]=[UIFont systemFontOfSize:18];
    textAttrs[UITextAttributeTextShadowOffset]=[NSValue valueWithUIOffset:UIOffsetZero];
    textAttrs[UITextAttributeFont]=[UIFont boldSystemFontOfSize:20];
    [navBar setTitleTextAttributes:textAttrs];
    
    //去掉导航栏但会按钮自带的文字
    [[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)
forBarMetrics:UIBarMetricsDefault];
}

//设置导航栏按钮主题
+(void)setupBarButtonItemTheme
{
    UIBarButtonItem *item=[UIBarButtonItem appearance];
    //设置文字属性
    NSMutableDictionary *textAttrs=[NSMutableDictionary dictionary];
    textAttrs[UITextAttributeTextColor]=[UIColor whiteColor];
    textAttrs[UITextAttributeTextShadowOffset]=[NSValue valueWithUIOffset:UIOffsetZero];
    textAttrs[UITextAttributeFont]=[UIFont systemFontOfSize:16];
    
    [item setTitleTextAttributes:textAttrs forState:UIControlStateNormal];
    [item setTitleTextAttributes:textAttrs forState:UIControlStateHighlighted];

}

3.如果对苹果系统自带的返回按钮不满意，想用自己的返回按钮（我以图片按钮为例）

    UIButton *leftButton=[[UIButton alloc]init];
    [leftButton setImage:[UIImage imageNamed:@"ct_icon_leftbutton"] forState:UIControlStateNormal];
    leftButton.frame=CGRectMake(0, 0, 25, 25);
    [leftButton setImageEdgeInsets:UIEdgeInsetsMake(0, -10, 0, 0)];
    [leftButton addTarget:self action:@selector(leftBtnClicked) forControlEvents:UIControlEventTouchUpInside];

    UIBarButtonItem *leftItem=[[UIBarButtonItem alloc]initWithCustomView:leftButton];

<p class="p1"><span class="s1">    </span><span class="s2">self</span><span class="s1">.</span><span class="s3">navigationItem</span><span class="s1">.</span><span class="s3">leftBarButtonItem</span><span class="s1"> = leftItem;</span></p>4.自定义返回按钮会失去系统自带的从左往右，从右往左切换效果。要想实现：<pre name="code" class="objc">- (void)leftBtnClicked

{
  
  for (UIViewController *controller in self.navigationController.viewControllers) 

  {
    
    if ([controller isKindOfClass:[上一个控制器 class]]) 

    {
      
      [self.navigationController popToViewController:controller animated:YES];
      
    }
    
  }
}

上面代码也可以实现从一个控制器返回上上个控制器，而不是上一个控制器。

 5.如果想在导航栏放自己想要放的东西：

- (void)setNaviBarItemButton{
  
  UILabel *titleView=[[UILabel alloc]init];
  [titleView setText:@"家居"];
  titleView.frame=CGRectMake(0, 0, 100, 16);
  titleView.font=[UIFont systemFontOfSize:16];
  [titleView setTextColor:[UIColor whiteColor]];
  titleView.textAlignment=NSTextAlignmentCenter;
  self.navigationItem.titleView=titleView;
  
  
  UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] initWithTitle:@"删除"
                                                                  style:UIBarButtonItemStyleDone
                                                                 target:self
                                                                 action:@selector(rightBtnClicked)];
  
    UIButton *leftButton=[[UIButton alloc]init];
    [leftButton setImage:[UIImage imageNamed:@"ct_icon_leftbutton"] forState:UIControlStateNormal];
    leftButton.frame=CGRectMake(0, 0, 25, 25);
    [leftButton setImageEdgeInsets:UIEdgeInsetsMake(0, -10, 0, 0)];
    [leftButton addTarget:self action:@selector(leftBtnClicked) forControlEvents:UIControlEventTouchUpInside];
    UIBarButtonItem *leftItem=[[UIBarButtonItem alloc]initWithCustomView:leftButton];
    
  
  rightButton.tintColor = [UIColor whiteColor];
  
  self.navigationItem.rightBarButtonItem = rightButton;
  self.navigationItem.leftBarButtonItem = leftItem;
  
}