使用KVC的方法替换系统的tabBar
首先继承UITabBarController和UITabBar创建俩类
本文只做点击中间按钮模态出一个界面的效果, 并不是把中间按钮做成和其他普通tabBar按钮一样对应的根控制器的效果
tabbar.h
@class LBTabBar;
@protocol LBTabBarDelegate <NSObject>
@optional
- (void)tabBarPlusBtnClick:(LBTabBar *)tabBar;
@end
@interface LBTabBar : UITabBar
/** tabbar的代理 */
@property (nonatomic, weak) id<LBTabBarDelegate> myDelegate ;
@end
tabBar.m里, 声明一个button
和#define LBMagin 10
初始化方法创建按钮, 添加点击事件
- (instancetype)initWithFrame:(CGRect)frame
{
if (self=[super initWithFrame:frame]) {
// ----runtime - test----
// unsigned int count = 0;
// Ivar *ivarList = class_copyIvarList([UITabBar class], &count);
// for (int i =0; i<count; i++) {
// Ivar ivar = ivarList[i];
// LBLog(@"%s",ivar_getName(ivar));
// }
//[self setBackgroundImage:[UIImage imageWithColor:[UIColor clearColor]]];
//设置tabBar背景颜色最好别这么写
// self.backgroundColor = [UIColor whiteColor];
// [self setShadowImage:[UIImage imageWithColor:[UIColor clearColor]]];
UIButton *plusBtn = [[UIButton alloc] init];
[plusBtn setBackgroundImage:[UIImage imageNamed:@"post_normal"] forState:UIControlStateNormal];
[plusBtn setBackgroundImage:[UIImage imageNamed:@"post_normal"] forState:UIControlStateHighlighted];
self.plusBtn = plusBtn;
[plusBtn addTarget:self action:@selector(plusBtnDidClick) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:plusBtn];
}
return self;
}
在子视图布局中, 遍历所有tabbarItem, 然后腾出中间的位置, 重点是遍历的UIView !
- (void)layoutSubviews
{
[super layoutSubviews];
//系统自带的按钮类型是UITabBarButton，找出这些类型的按钮，然后重新排布位置，空出中间的位置
Class class = NSClassFromString(@"UITabBarButton");
self.plusBtn.centerX = self.centerX;
//调整发布按钮的中线点Y值
self.plusBtn.centerY = self.height * 0.5 - 2*LBMagin ;
self.plusBtn.size = CGSizeMake(self.plusBtn.currentBackgroundImage.size.width, self.plusBtn.currentBackgroundImage.size.height);
UILabel *label = [[UILabel alloc] init];
label.text = @"发布";
label.font = [UIFont systemFontOfSize:11];
[label sizeToFit];
label.textColor = [UIColor grayColor];
[self addSubview:label];
label.centerX = self.plusBtn.centerX;
label.centerY = CGRectGetMaxY(self.plusBtn.frame) + LBMagin ;
int btnIndex = 0;
for (UIView *btn in self.subviews) {//遍历tabbar的子控件
if ([btn isKindOfClass:class]) {//如果是系统的UITabBarButton，那么就调整子控件位置，空出中间位置
//每一个按钮的宽度==tabbar的五分之一
btn.width = self.width / 5;
btn.x = btn.width * btnIndex;
btnIndex++;
//如果是索引是2(从0开始的)，直接让索引++，目的就是让消息按钮的位置向右移动，空出来发布按钮的位置
if (btnIndex == 2) {
btnIndex++;
}
}
}
[self bringSubviewToFront:self.plusBtn];
}
点击了发布按钮, 通过协议把点击事件传到tabbarcontroller
- (void)plusBtnDidClick
{
//如果tabbar的代理实现了对应的代理方法，那么就调用代理的该方法
if ([self.delegate respondsToSelector:@selector(tabBarPlusBtnClick:)]) {
[self.myDelegate tabBarPlusBtnClick:self];
}
}
重写hitTest方法，去监听发布按钮的点击，目的是为了让凸出的部分点击也有反应
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
//这一个判断是关键，不判断的话push到其他页面，点击发布按钮的位置也是会有反应的，这样就不好了
//self.isHidden == NO 说明当前页面是有tabbar的，那么肯定是在导航控制器的根控制器页面
//在导航控制器根控制器页面，那么我们就需要判断手指点击的位置是否在发布按钮身上
//是的话让发布按钮自己处理点击事件，不是的话让系统去处理点击事件就可以了
if (self.isHidden == NO) {
//将当前tabbar的触摸点转换坐标系，转换到发布按钮的身上，生成一个新的点
CGPoint newP = [self convertPoint:point toView:self.plusBtn];
//判断如果这个新的点是在发布按钮身上，那么处理点击事件最合适的view就是发布按钮
if ( [self.plusBtn pointInside:newP withEvent:event]) {
return self.plusBtn;
}else{//如果点不在发布按钮身上，直接让系统处理就可以了
return [super hitTest:point withEvent:event];
}
}
else {//tabbar隐藏了，那么说明已经push到其他的页面了，这个时候还是让系统去判断最合适的view处理就好了
return [super hitTest:point withEvent:event];
}
}
原作者在basenavigationController里的写法不错, 重写了push到下一界面总是要隐藏tabbar的麻烦
+ (void)load{
UIBarButtonItem *item=[UIBarButtonItem appearanceWhenContainedIn:self, nil ];
NSMutableDictionary *dic=[NSMutableDictionary dictionary];
dic[NSFontAttributeName]=[UIFont systemFontOfSize:15];
dic[NSForegroundColorAttributeName]=[UIColor blackColor];
[item setTitleTextAttributes:dic forState:UIControlStateNormal];
UINavigationBar *bar = [UINavigationBar appearanceWhenContainedInInstancesOfClasses:@[self]];
[bar setBackgroundImage:[UIImage imageWithColor:NavBarColor] forBarMetrics:UIBarMetricsDefault];
NSMutableDictionary *dicBar=[NSMutableDictionary dictionary];
dicBar[NSFontAttributeName]=[UIFont systemFontOfSize:15];
[bar setTitleTextAttributes:dic];
}
- (void)viewDidLoad {
[super viewDidLoad];
}
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
if (self.viewControllers.count > 0) {
viewController.hidesBottomBarWhenPushed = YES;
}
return [super pushViewController:viewController animated:animated];
}
来到tabbarController
初始化的时候定义一些字体属性
#pragma mark - 第一次使用当前类的时候对设置UITabBarItem的主题
+ (void)initialize
{
UITabBarItem *tabBarItem = [UITabBarItem appearanceWhenContainedInInstancesOfClasses:@[self]];
NSMutableDictionary *dictNormal = [NSMutableDictionary dictionary];
dictNormal[NSForegroundColorAttributeName] = [UIColor grayColor];
dictNormal[NSFontAttributeName] = [UIFont systemFontOfSize:11];
NSMutableDictionary *dictSelected = [NSMutableDictionary dictionary];
dictSelected[NSForegroundColorAttributeName] = [UIColor darkGrayColor];
dictSelected[NSFontAttributeName] = [UIFont systemFontOfSize:11];
[tabBarItem setTitleTextAttributes:dictNormal forState:UIControlStateNormal];
[tabBarItem setTitleTextAttributes:dictSelected forState:UIControlStateSelected];
}
视图加载完成时, 创建其余四个普通的tabBarItem并把系统的tabbar替换成自定义的那个
- (void)viewDidLoad {
[super viewDidLoad];
[self setUpAllChildVc];
//创建自己的tabbar，然后用kvc将自己的tabbar和系统的tabBar替换下
LBTabBar *tabbar = [[LBTabBar alloc] init];
tabbar.myDelegate = self;
//kvc实质是修改了系统的_tabBar
[self setValue:tabbar forKeyPath:@"tabBar"];
}
以下俩方法是对普通的tabbaritem的创建, 同样, 原作者的封装值得学习(第二个方法)
#pragma mark - ------------------------------------------------------------------
#pragma mark - 初始化tabBar上除了中间按钮之外所有的按钮
- (void)setUpAllChildVc{
LBHomeViewController *HomeVC = [[LBHomeViewController alloc] init];
[self setUpOneChildVcWithVc:HomeVC Image:@"home_normal" selectedImage:@"home_highlight" title:@"首页"];
LBFishViewController *FishVC = [[LBFishViewController alloc] init];
[self setUpOneChildVcWithVc:FishVC Image:@"fish_normal" selectedImage:@"fish_highlight" title:@"鱼塘"];
LBMessageViewController *MessageVC = [[LBMessageViewController alloc] init];
[self setUpOneChildVcWithVc:MessageVC Image:@"message_normal" selectedImage:@"message_highlight" title:@"消息"];
LBMineViewController *MineVC = [[LBMineViewController alloc] init];
[self setUpOneChildVcWithVc:MineVC Image:@"account_normal" selectedImage:@"account_highlight" title:@"我的"];
}
#pragma mark - 初始化设置tabBar上面单个按钮的方法
/**
* @author li bo, 16/05/10
*
* 设置单个tabBarButton
*
* @param Vc 每一个按钮对应的控制器
* @param image 每一个按钮对应的普通状态下图片
* @param selectedImage 每一个按钮对应的选中状态下的图片
* @param title 每一个按钮对应的标题
*/
- (void)setUpOneChildVcWithVc:(UIViewController *)Vc Image:(NSString *)image selectedImage:(NSString *)selectedImage title:(NSString *)title
{
LBNavigationController *nav = [[LBNavigationController alloc] initWithRootViewController:Vc];
Vc.view.backgroundColor = [self randomColor];
UIImage *myImage = [UIImage imageNamed:image];
myImage = [myImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
//tabBarItem，是系统提供模型，专门负责tabbar上按钮的文字以及图片展示
Vc.tabBarItem.image = myImage;
UIImage *mySelectedImage = [UIImage imageNamed:selectedImage];
mySelectedImage = [mySelectedImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
Vc.tabBarItem.selectedImage = mySelectedImage;
Vc.tabBarItem.title = title;
Vc.navigationItem.title = title;
[self addChildViewController:nav];
}
前面tabbar的协议方法在这里实现(模态出一个界面)
#pragma mark - ------------------------------------------------------------------
#pragma mark - LBTabBarDelegate
//点击中间按钮的代理方法
- (void)tabBarPlusBtnClick:(LBTabBar *)tabBar{
LBpostViewController *plusVC = [[LBpostViewController alloc] init];
plusVC.view.backgroundColor = [self randomColor];
LBNavigationController *navVc = [[LBNavigationController alloc] initWithRootViewController:plusVC];
[self presentViewController:navVc animated:YES completion:nil];
}
//这是随机色, 为区分不同界面用的
- (UIColor *)randomColor
{
CGFloat r = arc4random_uniform(256);
CGFloat g = arc4random_uniform(256);
CGFloat b = arc4random_uniform(256);
return [UIColor colorWithRed:r/255.0 green:g/255.0 blue:b/255.0 alpha:1.0];
}
