iOS自定义TabBar底部栏

前言：更新了PPHub之后发现了了一个很有意思的功能，自定义底部栏。可以动态的更换BarItem的位置。想着就动手实现了下Demo，思路如下：

演示GIF

PPHub效果演示

思路

• 首先本地缓存一个ChidItems数组并作为默认数组展示。
• 点击进入自定义TabBar底部栏界面，并在点击完成的时候存储新的ChidItems数组和发送通知。
• UITabBarController接受通知，并重新初始化。并选择上
  一次selectedIndex的控制器。

核心代码

1.在DCTabBarController.m中声明两个数组：控制器数组和记录上一次排序Items数组。并且接受更新通知。

/* 控制器Vc */
@property (nonatomic, strong) NSMutableArray *childVcArray;
/* 旧items数组 */
@property (nonatomic, copy) NSArray *oldChildArray;

#pragma mark - 添加子控制器
- (void)addDcChildViewContorller
{
    NSMutableArray *newChildArray = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults]objectForKey:@"tabBarItems"]];
    if ([newChildArray isEqual:_oldChildArray]) return; //如果数组顺序未更改则返回
    NSArray *normalArray = @[
                             @{MallClassKey  : @"DCBaseViewController",
                               MallTitleKey  : @"美信",
                               MallImgKey    : @"tabr_01_up",
                               MallSelImgKey : @"tabr_01_down"},
                             
                             @{MallClassKey  : @"DCBaseViewController",
                               MallTitleKey  : @"商城",
                               MallImgKey    : @"tabr_02_up",
                               MallSelImgKey : @"tabr_02_down"},
                             
                             @{MallClassKey  : @"DCBaseViewController",
                               MallTitleKey  : @"美媒榜",
                               MallImgKey    : @"tabr_03_up",
                               MallSelImgKey : @"tabr_03_down"},
                             
                             @{MallClassKey  : @"DCBaseViewController",
                               MallTitleKey  : @"美店",
                               MallImgKey    : @"tabr_04_up",
                               MallSelImgKey : @"tabr_04_down"},
                             
                             @{MallClassKey  : @"DCBaseViewController",
                               MallTitleKey  : @"我的",
                               MallImgKey    : @"tabr_05_up",
                               MallSelImgKey : @"tabr_05_down"},
                             
                             ];
    NSArray *childArray = (array.count == 0) ?  normalArray : newChildArray;
    
    __weak typeof(self)weakSelf = self;
    [self.childVcArray removeAllObjects];
    
    NSInteger newTag = 0;
    if (self.childViewControllers.count != 0){
        for (NSInteger i = 0; i < childArray.count; i++) {
            if ([childArray[i][MallTitleKey] isEqualToString:self.oldChildArray[self.selectedIndex][MallTitleKey]]) {
                newTag = i;
            }
        }
    }
    
    [childArray enumerateObjectsUsingBlock:^(NSDictionary *dict, NSUInteger idx, BOOL * _Nonnull stop) {

        UIViewController *vc = [NSClassFromString(dict[MallClassKey]) new];
        vc.navigationItem.title = dict[MallTitleKey];

        NSLog(@"%@  %@",dict[MallTitleKey],vc.navigationItem.title);
        DCNavigationController *nav = [[DCNavigationController alloc] initWithRootViewController:vc];
        nav.tabBarItem.image = [UIImage imageNamed:dict[MallImgKey]];
        nav.tabBarItem.selectedImage = [[UIImage imageNamed:dict[MallSelImgKey]] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
        nav.tabBarItem.imageInsets = UIEdgeInsetsMake(6, 0,-6, 0);//（当只有图片的时候）需要自动调整

        // 添加子控制器至数组
        [weakSelf.childVcArray addObject:nav];
    }];
    
    self.oldChildArray = childArray;
    self.selectedIndex = newTag;
    self.viewControllers = weakSelf.childVcArray;
    
    [[NSUserDefaults standardUserDefaults] setObject:childArray forKey:@"tabBarItems"];
    [[NSUserDefaults standardUserDefaults] synchronize];
}

这里我通过遍历找出上一次选中的控制器，并在重置后再次让其选中。

#pragma mark - 接受通知
- (void)accectNate
{
    __weak typeof(self)weakSelf = self;
    [[NSNotificationCenter defaultCenter]addObserverForName:@"updateTabBar" object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification * _Nonnull note) {
        
        [weakSelf addDcChildViewContorller]; //接受通知再次初始化
    }];
}

#pragma mark - 移除
- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

2.在更换TabBar顺序的控制器内打开编辑模式可拖动更改Items顺序，并且在点击确定后存储最新的tabItems数组并且发送通知。

a.介绍几个用到的代理方法

#pragma mark - 

- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
    return YES;
}
#pragma mark - 拖动
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath
{
    NSString *exchangeStr = _items[sourceIndexPath.row];
    //根据拖动改变数组
    [_items removeObjectAtIndex:sourceIndexPath.row];
    [_items insertObject:exchangeStr atIndex:destinationIndexPath.row];
}

#pragma mark - 编辑模式下StyleNone
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return UITableViewCellEditingStyleNone;
}

#pragma mark - 编辑模式下cell不缩进（默认缩进）
- (BOOL)tableView:(UITableView *)tableView shouldIndentWhileEditingRowAtIndexPath:(NSIndexPath *)indexPath
{
    return NO;
}

b.点击完成保存数组，发送通知并返回

#pragma mark - 完成
- (void)overBarItemBtnClick
{
    [SVProgressHUD show];
    [SVProgressHUD setDefaultMaskType:SVProgressHUDMaskTypeBlack];
    
    [[NSUserDefaults standardUserDefaults] setObject:_items forKey:@"tabBarItems"]; //存储最新items数组
    [[NSUserDefaults standardUserDefaults] synchronize];
    
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        
        [SVProgressHUD dismiss];
        
        [[NSNotificationCenter defaultCenter] postNotificationName:@"updateTabBar" object:nil];
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            
            [self.navigationController popViewControllerAnimated:YES];
        });
    });

}

3.实现效果

实现demo

最后如果你有更好的想法欢迎指教~