iOS的导航栏一直是很多人的头疼问题，因为在自定义的时候会出现各种各样的bug，本文总结了目前遇到的问题，及解决方案，希望能帮到大家。
1.想要每个页面导航栏颜色不一样并且在切换时互不影响。
其实系统的导航控制器很是好用，我们也不要去太多干涉它以免影响基础结构。我参考kenshinCui的文章，使用以下方案：
继承一个导航控制器，把导航栏背景色设置为一张空图片，达到透明效果，这样在使用的时候，可以自定义一张图片放上去充当导航栏背景，很是方便。
基类导航控制器:
.h
#import <UIKit/UIKit.h>
@interface TransNavigationViewController : UINavigationController
@end
.m
#import "TransNavigationViewController.h"
@interface TransNavigationViewController ()<UINavigationControllerDelegate,UIGestureRecognizerDelegate>
@end
@implementation TransNavigationViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
[self.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
self.navigationBar.shadowImage = [UIImage new];
self.interactivePopGestureRecognizer.delegate = self;
self.delegate = self;
}
-(void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated{
if (animated) {
self.interactivePopGestureRecognizer.delegate = self;
}
[super pushViewController:viewController animated:animated];
}
-(NSArray<UIViewController *> *)popToViewController:(UIViewController *)viewController animated:(BOOL)animated{
if (animated) {
self.interactivePopGestureRecognizer.delegate = self;
}
return [super popToViewController:viewController animated:animated];
}
-(NSArray<UIViewController *> *)popToRootViewControllerAnimated:(BOOL)animated{
if (animated) {
self.interactivePopGestureRecognizer.delegate = self;
}
return [super popToRootViewControllerAnimated:animated];
}
-(void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated{
[self.interactivePopGestureRecognizer setEnabled:YES];
}
-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
if (gestureRecognizer == self.interactivePopGestureRecognizer && self.viewControllers.count < 2) {
return NO;
}
return YES;
}
在工程中的导航控制器用这一个就够了。
具体在某个页面时，想要不同的背景色，添加一个自定义view就行了。
像这样：
在viewDidLoad中使用
GLNavigationBar *navigationBackView = [[GLNavigationBar alloc] initWithVisualView:YES];
navigationBackView = [UIColor groupTableViewBackgroundColor];
[self.view addSubview: navigationBackView];
我的背景专用view GLNavigationBar
GLNavigationBar.h
#import <UIKit/UIKit.h>
@interface GLNavigationBar : UIView
/**
导航栏除去状态栏的部分，可用来添加自定义view
*/
@property(nonatomic,strong)UIView *viewWithoutStatusBar;
/**
生成导航栏背景并且可以创建毛玻璃效果
@param visual 是否带毛玻璃效果
@return self
*/
-(instancetype)initWithVisualView:(BOOL)visual;
/**
使用自定义的frame生成导航栏背景并且可以创建毛玻璃效果
@param visual 是否带毛玻璃效果
@param frame 自定义的frame
@return self
*/
-(instancetype)initWithVisualView:(BOOL)visual frame:(CGRect)frame;
/**
专为包含搜索框的导航栏创建背景
@param visual 是否带毛玻璃
@return self
*/
-(instancetype)initWithSearchBarVisual:(BOOL)visual;
@end
GLNavigationBar.m
#import "GLNavigationBar.h"
@interface GLNavigationBar ()
@property(nonatomic,assign)CGRect realFrame;
@property(nonatomic,assign)CGRect searchFrame;
@end
@implementation GLNavigationBar
-(CGRect)realFrame{
//适配iPhoneX
CGFloat height = 64;
if ([UIScreen mainScreen].bounds.size.height == 812) {
height = 88;
}
return CGRectMake(0, 0,SCREEN_WIDTH ,height);
}
-(CGRect)searchFrame{
//适配iPhoneX
CGFloat height = 64 + 12;
if ([UIScreen mainScreen].bounds.size.height == 812) {
height = 88 + 12;
}
return CGRectMake(0, 0,SCREEN_WIDTH ,height);
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
// Drawing code
}
*/
-(instancetype)init{
if (self = [super init]) {
}
return self;
}
-(instancetype)initWithVisualView:(BOOL)visual{
if (self = [super initWithFrame:self.realFrame]){
if (visual) {
[self addVisualView:self.realFrame];
}
}
return self;
}
-(void)addVisualView:(CGRect)frame{
UIBlurEffect *blur;
blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
UIVisualEffectView *visualView = [[UIVisualEffectView alloc] initWithEffect:blur];
visualView.frame = frame;
[self addSubview:visualView];
}
-(instancetype)initWithSearchBarVisual:(BOOL)visual{
if (self = [super initWithFrame:self.searchFrame]) {
if (visual) {
[self addVisualView:self.searchFrame];
}
}
return self;
}
-(instancetype)initWithVisualView:(BOOL)visual frame:(CGRect)frame{
if (self = [super initWithFrame:frame]){
if (visual) {
[self addVisualView:frame];
}
}
return self;
}
-(instancetype)initWithFrame:(CGRect)frame{
//如果有frame值就使用，否则默认标准导航栏的尺寸
if (frame.size.width) {
self = [super initWithFrame:frame];
}else{
CGRect viewWithoutStatusBarFrame;
//适配iPhoneX
if ([UIScreen mainScreen].bounds.size.height == 812) {
viewWithoutStatusBarFrame = CGRectMake(0, 44,SCREEN_WIDTH, 44);
}else{
viewWithoutStatusBarFrame = CGRectMake(0, 20, SCREEN_WIDTH, 44);
}
self = [super initWithFrame:self.realFrame];
_viewWithoutStatusBar = [[UIView alloc] initWithFrame:viewWithoutStatusBarFrame];
_viewWithoutStatusBar.backgroundColor = [UIColor clearColor];
[self addSubview:_viewWithoutStatusBar];
}
return self;
}
@end
比如我这有两个viewController，要求分别有不同的导航栏背景:
navi.gif
可以看到切换非常丝滑，没有那种卡顿的bug。
2.自定义返回图标
如果只是想改变返回图标，系统自带的上一级的控制器名称还要的话，那就这样
UIImage *highlighted_backImage = [[UIImage imageNamed:@"navigationbar_back_highlighted"] imageWithRenderingMode:UIImageRenderingModeAutomatic];
//设置返回图标
self.navigationController.navigationBar.backIndicatorImage = highlighted_backImage;
self.navigationController.navigationBar.backIndicatorTransitionMaskImage = highlighted_backImage;
其实更多的需求是顺便连返回文字都不要了，只想要在左边留一个返回图标,刚开始思路是那就把系统的返回图标设置为我的图片，然后设置一个新的返回按钮，名称为空字符串
UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
self.navigationItem.backBarButtonItem = item;
,这种方法很容易造成一个问题，就是返回图片不居中。
应该通过调整尺寸可以解决，但是我懒得慢慢去试，而且限制图片尺寸这件事本来就很局限，所以我用了下面这个方法：
1.首先把一张空图片设置成返回图标，其实是看不见的。然后用你自己的返回图标创建一个UIBarButtonItem赋给返回按钮，就OK了。
back.png
如果项目风格统一，可以直接用runtime解决，新建一个UIViewController的category，具体代码如下：
#import "UIViewController+BackImage.h"
#import <objc/runtime.h>
@implementation UIViewController (BackImage)
+ (void)load {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class class = [self class];
SEL originalSelector = @selector(viewDidLoad);
SEL swizzledSelector = @selector(back_viewDidLoad);
Method originalMethod = class_getInstanceMethod(class, originalSelector);
Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
BOOL didAddMethod = class_addMethod(class, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod));
if (didAddMethod) {
class_replaceMethod(class, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));
} else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
});
}
#pragma mark - Method Swizzling
- (void)back_viewDidLoad {
[self back_viewDidLoad];
//设置返回图标为空
self.navigationController.navigationBar.backIndicatorImage = [UIImage new];
self.navigationController.navigationBar.backIndicatorTransitionMaskImage = [UIImage new];
//导航栏返回按钮
UIImage *highlighted_backImage = [[UIImage imageNamed:@"navigationbar_back_highlighted"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
UIBarButtonItem *backButton = [[UIBarButtonItem alloc]initWithImage:highlighted_backImage style:UIBarButtonItemStylePlain target:self action:@selector(gl_private_popViewController)];
[self.navigationItem setBackBarButtonItem:backButton];
}
-(void)gl_private_popViewController{
[self.navigationController popViewControllerAnimated:YES];
}
@end
如果你只是希望某几个控制器用这种风格，可以在runtime里判断，或者干脆建个基类解决。
附，kenshinCui大神的博客地址： iOS开发tips-UINavigationBar的切换
以上
网友评论