自定义navbar

实习中遇到了一个问题，使用系统自带UINavigationController的时候，有些效果做不到。比如各个界面的navbar需要不同的颜色，pop的时候颜色切换很不自然

push后.png pop时.png

这样的效果很不美观，而很多知名APP的切换是非常自然的，于是便去网上搜索解决办法

代码部分

自定义一个继承于UINavigationController的子类，添加如下方法（此方法可放在load方法里）

+ (void)setUpBase
{
    UINavigationBar *bar = [UINavigationBar appearance];
    bar.barTintColor = [UIColor redColor];
    [bar setTintColor:[UIColor darkGrayColor]];
    bar.translucent = YES;
    [bar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
    [bar setShadowImage:[UIImage new]];
    NSMutableDictionary *attributes = [NSMutableDictionary dictionary];
    // 设置导航栏字体颜色
    UIColor * naiColor = SYJColor(100, 100, 100, 1);
    attributes[NSForegroundColorAttributeName] = naiColor;
    attributes[NSFontAttributeName] = [UIFont systemFontOfSize:18];;
    bar.titleTextAttributes = attributes;
}

重写pushViewController方法

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (self.childViewControllers.count > 0) {
        viewController.hidesBottomBarWhenPushed = YES;
        // 就有滑动返回功能
        self.interactivePopGestureRecognizer.delegate = nil;
        //返回按钮自定义
        UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
        negativeSpacer.width = -15;
        
        UIButton *button = [[UIButton alloc] init];
        [button setImage:[UIImage imageNamed:@"返回"] forState:UIControlStateNormal];
        [button setImage:[UIImage imageNamed:@"返回"] forState:UIControlStateHighlighted];
        button.frame = CGRectMake(0, 0, 33, 33);
        
        if (@available(ios 11.0,*)) {
            button.contentEdgeInsets = UIEdgeInsetsMake(0, -15,0, 0);
            button.imageEdgeInsets = UIEdgeInsetsMake(0, -10,0, 0);
        }
        
        [button addTarget:self action:@selector(backButtonTapClick) forControlEvents:UIControlEventTouchUpInside];
        UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithCustomView:button];
        
        viewController.navigationItem.leftBarButtonItems = @[negativeSpacer, backButton];
    }
    [super pushViewController:viewController animated:animated];
}
#pragma mark - 点击
- (void)backButtonTapClick {
    
    [self popViewControllerAnimated:YES];
}

然后在你各个UIViewController中添加一个view

    UIView *view=[[UIView alloc]initWithFrame:CGRectMake(0, 0, ScreenWidth, NAVBAR_HEIGHT+STATUS_HEIGHT)];//NAVBAR_HEIGHT+STATUS_HEIGHT指navbar的高度和status的高度
    view.backgroundColor=[UIColor redColor];//加上你要的颜色
    [self.view addSubview:view];

效果

push后.png
pop时.png