公司的产品要求做一个很通用框架的APP，在整个APP构思的过程中还是有很多误区，以下为一些初步总结：
一、UINavigationController+UITabBarController 和 UITabBarController +UINavigationController差别
UITabBarController +UINavigationController ,从ViewController1push到下一个ViewController，UITabBar会自动消失:

UITabBarController *tabbar = [[UITabBarController alloc] init];
    ViewController1 *v1 = [[ViewController1 alloc] init];
    [tabbar addChildViewController:v1];
    ViewControllerB *vb = [[ViewControllerB alloc] init];
    [tabbar addChildViewController:vb];
    MeViewController *me = [[MeViewController alloc] init];
    [tabbar addChildViewController:me];
    UINavigationController  *nav = [[UINavigationController alloc] initWithRootViewController:tabbar];
    nav.navigationBar.barTintColor = [UIColor redColor];
    self.window.rootViewController = nav;

UINavigationController+UITabBarController 从ViewController1push到下一个ViewController，UITabBar不会自动消失，可以通过系统自带的hidesBottomBarWhenPushed使UITabBar隐藏，全都用原生的是没有问题的，但是如果结合WKWebView，因为有网络请求和页面加载的时差，导致加载过程中UITabBar会是黑色的背景，用户体验很差:

   UITabBarController *tabbar = [[UITabBarController alloc] init];
 ViewController1 *v1 = [[ViewController1 alloc] init];
  UINavigationController  *nav1 = [[UINavigationController alloc]   initWithRootViewController:v1];
    [tabbar addChildViewController:nav1];
    ViewController2 *v2 = [[ViewController2 alloc] init];
  UINavigationController  *nav2 = [[UINavigationController alloc]   initWithRootViewController:v2];
    [tabbar addChildViewController:nav2];
    self.window.rootViewController = tabbar;

二，合理抽取类

图片.png

UITabBar显示的ViewController与点击ViewController进去的页面抽取为2重不同的ViewController考虑为以下几点：
①，frame的不同，UITabBar显示的ViewController的frame需要减去tabbar的高度，而点进去的ViewController则不需要减去tabbar的高度
②，点击ViewController进去的页面只需要创建一次，其余交互页面在该页面交互即可，不用每次点击新页面就创建新的ViewController
③，用户体验好，当用户点击了UITabBar页面的ViewController立即创建新的ViewController，显示加载中，接近原生效果
附上实例代码参考：
CommonWebViewVC

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{
    
    NSString *url = [navigationAction.request.URL.absoluteString stringByRemovingPercentEncoding];
    NSString* reUrl=[[webView URL] absoluteString];
    if ([url containsString:kBaseUrl]||[url containsString:kProductBaseUrl])
    {
        reUrl=url;
    }
   
    if ([self show:reUrl]) {
        decisionHandler(WKNavigationActionPolicyCancel);
        SecondWebViewController* vc=[[SecondWebViewController alloc] init];
        vc.delegate = self;
        vc.webViewUrl=reUrl;
        NSLog(@"redirectUrl=%@",reUrl);
        [self.navigationController pushViewController:vc animated:YES];
    }else{
        decisionHandler(WKNavigationActionPolicyAllow);
         NSLog(@"redirectUrl=%@,allow",reUrl);

    }
}


-(BOOL)show:(NSString*) url{
    return false;
}

BaseAppWebviewViewController

@interface BaseAppWebviewViewController : CommonWebViewVC
-(NSString*)loadUrl;
@end

- (void)viewDidLoad {
    [super viewDidLoad];
    self.edgesForExtendedLayout = UIRectEdgeNone;
    self.automaticallyAdjustsScrollViewInsets = NO;
    self.webView.frame = CGRectMake(0, 0, kScreenWidth, kScreenHeight  - kTabbarH);
    // Do any additional setup after loading the view.
}


-(BOOL)show:(NSString *)url{//YES 拦截
//如果要跳转的页面不是当前页面和空页面
    if (![url isEqualToString:[self loadUrl]]&&![[UrlCollection blankURL] isEqualToString:url]) {
        return YES;
    }
    return NO;
}
- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    self.navigationController.navigationBar.hidden = YES;
}

SecondWebViewController

@interface SecondWebViewController : CommonWebViewVC

@end

- (void)viewDidLoad {
    [super viewDidLoad];
    self.webView.frame = CGRectMake(0, kStatusH, kScreenWidth, kScreenHeight - kStatusH);
}
- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
     //将status bar 文本颜色设置为白色,当前页面为白色
    self.navigationController.navigationBar.barStyle = UIBarStyleDefault;
    self.navigationController.navigationBar.hidden = YES;
    
}