當在一個頁面觸發一個事件跳轉到一個H5頁面時,H5頁面內部也可以進行下一級的跳轉,這個時候我們導航欄使用蘋果原生的返回按鈕就需要處理頁面中的返回效果。是返回到pushH5的上一級頁面還是返回H5內部的上一級頁面?

- (void)viewDidLoad {
     [super viewDidLoad];
     UIButton * backButton = [UIButton buttonWithType:UIButtonTypeSystem];
     backButton.frame = CGRectMake(10, 20, 20, 20);
     [backButton setBackgroundImage:[UIImage imageNamed:@"goBackImage"] forState:UIControlStateNormal];
     [backButton addTarget:self action:@selector(back:) forControlEvents:UIControlEventTouchUpInside];
     self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:backButton];
     
     self.webView =[[UIWebView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height)];
     _webView.backgroundColor = [UIColor clearColor];
     for (UIView * views in [self.webView subviews]) {
          if ([views isKindOfClass:[UIScrollView class]]) {
               //去掉水平方向的滑動條
               [(UIScrollView *)views setShowsHorizontalScrollIndicator:NO];
               //去掉垂直方向的滑動條
               [(UIScrollView *)views setShowsVerticalScrollIndicator:NO];
               for (UIView * inScrollView in views.subviews) {
                    if ([inScrollView isKindOfClass:[UIImageView class]]) {
                         //隱藏上下滾動出邊界時的黑色的圖片
                         inScrollView.hidden = YES;
                    }
               }
          }
     }
     NSString * urlString = [NSString stringWithFormat:@"%@xxxxxxxx",BASE_URL];
     NSURL * url = [NSURL URLWithString:urlString];
     NSURLRequest * request = [NSURLRequest requestWithURL:url];
     _webView.delegate = self;
     [_webView loadRequest:request];
     [self.view addSubview:self.webView];
}

//用蘋果自帶的返回鍵按鈕處理如下(自定義的返回按鈕)
- (void)back:(UIBarButtonItem *)btn
{
     if ([self.webView canGoBack]) {
          [self.webView goBack];
          
     }else{
          [self.view resignFirstResponder];
          [self.navigationController popViewControllerAnimated:YES];
     }
}


//如果是H5頁面里面自帶的返回按鈕處理如下:
#pragma mark - webViewDelegate
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
     NSString * requestString = [[request URL] absoluteString];
     requestString = [requestString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
     //獲取H5頁面里面按鈕的操作方法,根據這個進行判斷返回是內部的還是push的上一級頁面
     if ([requestString hasPrefix:@"goback:"]) {
          [self.navigationController popViewControllerAnimated:YES];
     }else{
          [self.webView goBack];
     }
     return YES;
}

//獲取當前頁面的title和url
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
     
     [SVProgressHUD dismiss];
     NSString * title = [webView stringByEvaluatingJavaScriptFromString:@"document.title"];//獲取當前頁面的title
     self.title = title;
     //獲取當前網頁的html
     self.currentURL = webView.request.URL.absoluteString;
     NSLog(@"title-%@--url-%@--",self.title,self.currentURL);
     NSString *lJs = @"document.documentElement.innerHTML";
     self.currentHTML = [webView stringByEvaluatingJavaScriptFromString:lJs];
}