风格一致的backItem在项目中怎样设置

在相应的navigationController中重写- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated方法

参照代码：

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (self.childViewControllers.count > 0) { // 如果push进来的不是第一个控制器
        UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
        [button setTitle:@"返回" forState:UIControlStateNormal];
        [button setImage:[UIImage imageNamed:@"navigationButtonReturn"] forState:UIControlStateNormal];
        [button setImage:[UIImage imageNamed:@"navigationButtonReturnClick"] forState:UIControlStateHighlighted];
        button.size = CGSizeMake(70, 30);
        // 让按钮内部的所有内容左对齐
        button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
        button.backgroundColor = [UIColor redColor];
//        [button sizeToFit];
        // 让按钮的内容往左边偏移10
        button.contentEdgeInsets = UIEdgeInsetsMake(0, -10, 0, 0);
        [button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [button setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
        [button addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
        
        // 修改导航栏左边的item
        viewController.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:button];
        
        // 隐藏tabbar
        viewController.hidesBottomBarWhenPushed = YES;
    }
    
    // 这句super的push要放在后面, 让viewController可以覆盖上面设置的leftBarButtonItem
    [super pushViewController:viewController animated:animated];
    
}