统一设置 " 返回 " 按钮

方法一 : 在 NavigationController 中, 重写父类的push方法

/**
* 拦截所有push进来的子控制器
* @param viewController 每一次push进来的子控制器
*/
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
  //    if (不是第一个push进来的子控制器) {
  if (self.childViewControllers.count >= 1) {
      // 左上角的返回
      UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
      [backButton setTitle:@"返回" forState:UIControlStateNormal];
      [backButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
      [backButton setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
      [backButton setImage:[UIImage imageNamed:@"navigationButtonReturn"] forState:UIControlStateNormal];
      [backButton setImage:[UIImage imageNamed:@"navigationButtonReturnClick"] forState:UIControlStateHighlighted];
      [backButton sizeToFit];
      [backButton addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
      backButton.contentEdgeInsets = UIEdgeInsetsMake(0, -20, 0, 0);
      viewController.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
      viewController.hidesBottomBarWhenPushed = YES; // 隐藏底部的工具条
  }

  // super的push方法一定要写到最后面
  // 一旦调用super的pushViewController方法,就会创建子控制器viewController的view
  // 也就会调用viewController的viewDidLoad方法
  [super pushViewController:viewController animated:animated];
}
- (void)back
{
  [self popViewControllerAnimated:YES];
}

方法二 : 在BaseViewController 中, 写一个 - (void)setupNavigationwithTitle:(NSString *)title; 方法, 然后, 在需要 "返回" 按钮的页面, 调用此方法.

/**
 *  设置navigationbar的title（同时还默认的包含有设置返回按钮为黑色）
 *
 *  @param title title的内容
 */
- (void)setupNavigationwithTitle:(NSString *)title;

- (void)setupNavigationwithTitle:(NSString *)title {
    
    UIButton *backBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    backBtn.frame = CGRectMake(0.0, 0.0, 80.0, 40.0);
    UIImageView *backImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"back_black"]];
    backImg.frame = CGRectMake(-14.0, 2.0, 30.0, 40.0);
    [backBtn addSubview:backImg];
    
    UILabel *backLabel = [[UILabel alloc]init];
    backLabel.text = @"返回";
    backLabel.textColor = [UIColor whiteColor];
    backLabel.font = [UIFont systemFontWithSize:16.0f];
    backLabel.frame = CGRectMake(10, 2.0, 40, 40);
    
    [backBtn addSubview:backLabel];
    
    [backBtn addTarget:self
                action:@selector(btnItemClick)
      forControlEvents:UIControlEventTouchUpInside];
    UIBarButtonItem *leftButton = [[UIBarButtonItem alloc] initWithCustomView:backBtn];
    [self.navigationItem setLeftBarButtonItem:leftButton];
    
    self.title = title;
    
}
- (void)btnItemClick
{
    [self.navigationController popViewControllerAnimated:YES];

}