UINavigationController的创建和相关设置---学习笔记四

#import "BSJMainNavViewController.h"

@interface BSJMainNavViewController ()<UIGestureRecognizerDelegate>

@end

@implementation BSJMainNavViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    UINavigationBar *navBar =  [UINavigationBar appearance];
    NSMutableDictionary *navInfo = [NSMutableDictionary dictionary];
    navInfo[NSFontAttributeName] = [UIFont systemFontOfSize:16];
    [navBar setBackgroundImage:[UIImage imageNamed:@"navigationbarBackgroundWhite"] forBarMetrics:UIBarMetricsDefault];
    [navBar setTitleTextAttributes:navInfo];
    
    //当重写导航的push方法时，导航的手势就失效了，可以这样写
    self.interactivePopGestureRecognizer.delegate = self;
    
}

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated{
   
    if (self.childViewControllers.count >=1) {
        
        UIButton *leftButton = [[UIButton alloc] init];
        [leftButton setImage:[UIImage imageNamed:@"navigationButtonReturn"] forState:UIControlStateNormal];
        [leftButton setImage:[UIImage imageNamed:@"navigationButtonReturnClick"] forState:UIControlStateHighlighted];
        [leftButton setTitle:@"返回" forState:UIControlStateNormal];
        [leftButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [leftButton setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
        [leftButton sizeToFit];
        [leftButton addTarget:self action:@selector(backItemClick:) forControlEvents:UIControlEventTouchUpInside];
        //按钮中有个imageView 和Label
        //设置这个是设置imageView的内边距，如果设置它会imageView向内缩进
//        leftButton setImageEdgeInsets:<#(UIEdgeInsets)#>
        //设置这个是设置title的内边距，如果设置它会title向内缩进
//        leftButton setTitleEdgeInsets:<#(UIEdgeInsets)#>
        //设置整个按钮的内边距
        [leftButton setContentEdgeInsets:UIEdgeInsetsMake(0,-20, 0, 0)];
        viewController.hidesBottomBarWhenPushed = YES;
        viewController.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:leftButton];
    }
    
    //最后再调这段代码，上面的代码是先改导航的左边按钮
    [super pushViewController:viewController animated:animated];
    
}
#pragma mark --- delegate
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
    
    //因为如果不设置>1，在主页面这个手势也会起作用，这样的话就不能push了就有bug
    return self.childViewControllers.count > 1;
}
#pragma mark --- response methods
- (void)backItemClick:(UIButton *)sender{
    [self popViewControllerAnimated:YES];
}
@end