屏幕快照 2017-09-29 下午2.53.59.png

屏幕快照 2017-09-29 下午2.53.38.png

 - (void)viewDidLoad {
[self addLeftButton];
  }
  - (void)webViewDidFinishLoad:(UIWebView *)webView{

    //判断是否有上一层H5页面
if ([webView canGoBack]) {
    //如果有则返回
    //同时设置返回按钮和关闭按钮为导航栏左边的按钮
    self.navigationItem.leftBarButtonItems = @[self.backItem, self.closeItem];
} else {
    self.navigationItem.leftBarButtonItems = @[self.backItem];
}


}



//点击返回的方法
  - (void)backNative
{
//判断是否有上一层H5页面
if ([webView canGoBack]) {
    //如果有则返回
    [webView goBack];
  } else {
    [self closeNative];
}
}

//关闭H5页面，直接回到原生页面
- (void)closeNative
{
[self.navigationController popViewControllerAnimated:YES];
}

  #pragma mark - init

- (UIBarButtonItem *)backItem
{
if (!_backItem) {
    _backItem = [[UIBarButtonItem alloc] init];
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    
    UIImage *image = [UIImage imageNamed:@"返回"];
    [btn setImage:image forState:UIControlStateNormal];
    [btn setTitle:@"返回" forState:UIControlStateNormal];
    [btn addTarget:self action:@selector(backNative) forControlEvents:UIControlEventTouchUpInside];
    [btn.titleLabel setFont:[UIFont systemFontOfSize:17]];
//        [btn setTitleColor:[UIColor sy_backColor] forState:UIControlStateNormal];
    //字体的多少为btn的大小
    [btn sizeToFit];
    //左对齐
    btn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
    //让返回按钮内容继续向左边偏移15，如果不设置的话，就会发现返回按钮离屏幕的左边的距离有点儿大，不美观
    btn.contentEdgeInsets = UIEdgeInsetsMake(0, -15, 0, 0);
    btn.frame = CGRectMake(0, 0, 40, 40);
    _backItem.customView = btn;
}
return _backItem;
}

    - (UIBarButtonItem *)closeItem
{
if (!_closeItem) {
    _closeItem = [[UIBarButtonItem alloc] initWithTitle:@"关闭" style:UIBarButtonItemStylePlain target:self action:@selector(closeNative)];
}
return _closeItem;
}