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前言

例子:调整BarButtonItem按钮和titleView的间距

1、原理：titleview的起点位置和尺寸依赖于leftBarButtonItem和rightBarButtonItem的位置。

2、设置titleview之前，先初始化leftBarButtonItem和rightBarButtonItem的位置，然后根据leftBarButtonItem和rightBarButtonItem的位置来使titleview居中。

常见问题

1、 BarButtonItem 隐藏失效的解决方案：使用initWithCustomView进行实例化BarButtonItem

2、 iOS13.5.1 版本无法点击导航条右侧按钮：CustomView 不能直接是UIButton, 因此解决方案只要对UIButton进行包装一层之后再作为CustomView

I、调整BarButtonItem按钮和titleView的间距

与屏幕边界 或者与titleView 的间距 只要分别调整rightBarButtonItems 数组元素的顺序。

主要利用UIBarButtonItem 的UIBarButtonSystemItemFixedSpace 系统控件

 UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc]
                                       initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace
                                       target:nil action:nil];
    /**
     *  width为负数时，相当于btn向右移动width数值个像素，由于按钮本身和边界间距为5pix，所以width设为-5时，间距正好调整
     *  为0；width为正数时，正好相反，相当于往左移动width数值个像素
     */
    negativeSpacer.width = 10;

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1.1 调整右边按钮和titleView的间距

 //设置右边按钮
    UIBarButtonItem *btn_right =  [UIBarButtonItem barButtonItemWithTarget:self  Image:@"in" highlightedImage:@"in" actionMethod:@selector(in)];
    
    
    
    UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc]
                                       initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace
                                       target:nil action:nil];
    /**
     *  width为负数时，相当于btn向右移动width数值个像素，由于按钮本身和边界间距为5pix，所以width设为-5时，间距正好调整
     *  为0；width为正数时，正好相反，相当于往左移动width数值个像素
     */
    negativeSpacer.width = 10;
    self.navigationItem.rightBarButtonItems = [NSArray arrayWithObjects: btn_right, negativeSpacer,nil];
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1.2 调整左边按钮和titleView的间距

//    经过尝试，发现titleview的起点位置和尺寸依赖于leftBarButtonItem和rightBarButtonItem的位置。
    

        UILabel * centerView = [[UILabel alloc] initWithFrame:CGRectMake(kAdjustRatio(20),0 , self.view.frame.size.width- kAdjustRatio(20), self.navigationController.navigationBar.frame.size.height)];
    
    self.navigationItem.titleView = centerView;
    
//    设置titleview之前，先初始化leftBarButtonItem和rightBarButtonItem的位置，然后根据leftBarButtonItem和rightBarButtonItem的位置来使titleview居中。
    

//    self.navigationItem.titleView.
    
    
    UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc]
                                       initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace
                                       target:nil action:nil];
    /**
     *  width为负数时，相当于btn向右移动width数值个像素，由于按钮本身和边界间距为5pix，所以width设为-5时，间距正好调整
     *  为0；width为正数时，正好相反，相当于往左移动width数值个像素
     */

    negativeSpacer.width = 10;

    
//    self.navigationItem.leftBarButtonItem =negativeSpacer;

    self.navigationItem.leftBarButtonItems = [NSArray arrayWithObjects:  negativeSpacer,nil];

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1.3 设置webViewVC 导航条的左边按钮的位置

- (void)updateNavigationItems {
    [self.navigationItem setLeftBarButtonItems:nil animated:NO];
    if (self.webView.canGoBack/* || self.webView.backForwardList.backItem*/) {// Web view can go back means a lot requests exist.
        UIBarButtonItem *spaceButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
        spaceButtonItem.width = -6.5;
        self.navigationController.interactivePopGestureRecognizer.enabled = NO;
        if (self.navigationController.viewControllers.count == 1) {
            NSMutableArray *leftBarButtonItems = [NSMutableArray arrayWithArray:@[spaceButtonItem,self.navigationBackBarButtonItem]];
            // If the top view controller of the navigation controller is current vc, the close item is ignored.
            if (self.showsNavigationCloseBarButtonItem && self.navigationController.topViewController != self){
                [leftBarButtonItems addObject:self.navigationCloseBarButtonItem];
            }
            
            [self.navigationItem setLeftBarButtonItems:leftBarButtonItems animated:NO];
        } else {
            if (self.showsNavigationCloseBarButtonItem){
                [self.navigationItem setLeftBarButtonItems:@[self.navigationCloseBarButtonItem] animated:NO];
            }else{
                [self.navigationItem setLeftBarButtonItems:@[] animated:NO];
            }
        }
    } else {
        self.navigationController.interactivePopGestureRecognizer.enabled = YES;
        [self.navigationItem setLeftBarButtonItems:nil animated:NO];
    }
}

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II、相关的常见问题

2.1 self.navigationItem.leftBarButtonItem.customView.hidden=YES 失效

• UIBarButtonItem 使用initWithCustomView 进行实例化的时，这个方法才生效

self.navigationItem.leftBarButtonItem.customView.hidden=YES
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• 解决方法： 使用initWithCustomView 进行实例化

 UIBarButtonItem *lefttItem = [[UIBarButtonItem alloc]initWithCustomView:btn];

    
    self.navigationItem.leftBarButtonItem = lefttItem;

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2.2 iOS13.5.1 版本无法点击导航条右侧按钮

• 无法点击代码

//    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
//    [btn setTitle:QCTLocal(@"print") forState:UIControlStateNormal];
//    [btn setTitleColor:HWColor(51, 51, 51) forState:UIControlStateNormal];
//    btn.titleLabel.font = [UIFont systemFontOfSize:14.0f];
//    [btn addTarget:self action:@selector(printBtn:) forControlEvents:UIControlEventTouchUpInside];
//    btn.tag = 0;
//    btn.tintColor = [UIColor blackColor];
//    UIBarButtonItem *rightBtn = [[UIBarButtonItem alloc] initWithCustomView:btn];
//    rightBtn.tintColor = [UIColor blackColor];
//    self.navigationItem.rightBarButtonItem = rightBtn;

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• 解决方案

CustomView 不能直接是UIButton, 因此解决方案只要对UIButton进行包装一层即可

- (void)setupNavigationBar {
    // 设置导航条右侧的按钮
    UIButton *btn = [[UIButton alloc] init];
    //    [btn setImage:[UIImage imageNamed:@"icon_kaidan_huiyuan"] forState:UIControlStateNormal];
    [btn setTitle:QCTLocal(@"print") forState:UIControlStateNormal];
    [btn setTitleColor:rgb(51,51,51) forState:UIControlStateNormal];
    [btn addTarget:self action:@selector(printBtn:) forControlEvents:UIControlEventTouchDown];
    btn.titleLabel.font = kTextFont(14);
    [btn sizeToFit];
    UIView *btnView = [[UIView alloc] init];
    btnView.frame = btn.bounds;
    [btnView addSubview:btn];
    UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithCustomView:btnView];
    item.tintColor = [UIColor whiteColor];
    self.navigationItem.rightBarButtonItem = item;
    
    
    
    
    
}


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2.3 使用 [UIBarButtonItem alloc] initWithImage: 方法，导致图片颜色被冲的解决方案

从其他VC回到当前控制器的时候，发现右边的self.navigationItem.rightBarButtonItem的背景颜色被冲淡了

• 解决方法：UIImageRenderingModeAlwaysOriginal

    UIImage *aimage = [UIImage imageNamed:@"icon_right_menu"];
    UIImage *image = [aimage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    UIBarButtonItem *rightItem = [[UIBarButtonItem alloc] initWithImage:image style:UIBarButtonItemStylePlain target:self action:@selector(moreAction)];
    [self.navigationItem setRightBarButtonItem:rightItem animated:YES];



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III、 控制器的跳转和回退细节处理

3.1 UIActionSheet打开相册的处理：通常是等didDismissWithButtonIndex 之后才进行控制器跳转

- (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex NS_DEPRECATED_IOS(2_0, 8_3) __TVOS_PROHIBITED{
    
    if (buttonIndex == 0) {
        [self createCamera];
    }
}

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3.2 pop回栈中指定的VC

- (void)pop
{
    for (UIViewController *temp in self.navigationController.viewControllers) {
        if ([temp isKindOfClass:[QCTMyFinancialViewController class]]) {
            [self.navigationController popToViewController:temp animated:YES];
        }
    }
}
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IV、see also

感谢支持，更多内容请关注公众号：iOS逆向

常用的扩展方法

UIBarButtonItem (Extension)

@implementation UIBarButtonItem (Extension)
+ (UIBarButtonItem*)barButtonItemWithTarget:(id)target Image:(NSString*)imageName highlightedImage:(NSString*)highlightedImage actionMethod:(SEL)actionMethod{
    // 设置图片
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setBackgroundImage:[UIImage imageNamed:imageName] forState:UIControlStateNormal];
    [button setBackgroundImage:[UIImage imageNamed:highlightedImage] forState:UIControlStateHighlighted];
    //设置frame
    button.size = button.currentBackgroundImage.size;
    
    //设置监听
    [button addTarget:target action:actionMethod forControlEvents:UIControlEventTouchUpInside];
    return  [[UIBarButtonItem alloc]initWithCustomView:button];
}


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