如何在下方頂部的集合視圖中為部分添加標題

Question

我正在使用帶有搜索欄的集合視圖。 我已經通過 cod 添加了搜索欄，從頂部 (0,0) 開始。 所以現在我的圖像看起來像這樣：

[![在此處輸入圖像描述][1]][1]

但我需要在我的搜索欄下方標題。 我是通過故事板做的。但是在運行時，我的標題名稱和搜索欄在同一來源中。我需要將標題部分放在 myseaarch 欄下方。

注意：我正在唱 3 節標題。任何想法或代碼都非常有幫助。

這是我的搜索欄代碼...

#import "CollectionViewController.h"
#import "CollectionViewCell.h"
@interface CollectionViewController ()<UISearchBarDelegate>

    @property (nonatomic,strong) NSArray        *dataSource;
    @property (nonatomic,strong) NSArray        *dataSourceForSearchResult;
    @property (nonatomic)        BOOL           searchBarActive;
    @property (nonatomic)        float          searchBarBoundsY;

    @property (nonatomic,strong) UISearchBar        *searchBar;
    @property (nonatomic,strong) UIRefreshControl   *refreshControl;

@end

@implementation CollectionViewController

static NSString * const reuseIdentifier = @"Cell";

- (void)viewDidLoad {
    [super viewDidLoad];

    // Do any additional setup after loading the view.
    // datasource used when user search in collectionView
    self.dataSourceForSearchResult = [NSArray new];

    // normal datasource
    self.dataSource =@[@"Modesto",@"Rebecka",@"Andria",@"Sergio",@"Robby",@"Jacob",@"Lavera",@"Theola",@"Adella",@"Garry", @"Lawanda", @"Christiana", @"Billy", @"Claretta", @"Gina", @"Edna", @"Antoinette", @"Shantae", @"Jeniffer", @"Fred", @"Phylis", @"Raymon", @"Brenna", @"Gus", @"Ethan", @"Kimbery", @"Sunday", @"Darrin", @"Ruby", @"Babette", @"Latrisha", @"Dewey", @"Della", @"Dylan", @"Francina", @"Boyd", @"Willette", @"Mitsuko", @"Evan", @"Dagmar", @"Cecille", @"Doug", @"Jackeline", @"Yolanda", @"Patsy", @"Haley", @"Isaura", @"Tommye", @"Katherine", @"Vivian"];

}


-(void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    [self prepareUI];
}
-(void)dealloc{
    // remove Our KVO observer
    [self removeObservers];
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


#pragma mark - actions
-(void)refreashControlAction{
    [self cancelSearching];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        // stop refreshing after 2 seconds
        [self.collectionView reloadData];
        [self.refreshControl endRefreshing];
    });
}


#pragma mark - <UICollectionViewDataSource>
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    if (self.searchBarActive) {
        return self.dataSourceForSearchResult.count;
    }
    return self.dataSource.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:reuseIdentifier forIndexPath:indexPath];

    // Configure the cell
    if (self.searchBarActive) {
        cell.laName.text = self.dataSourceForSearchResult[indexPath.row];
    }else{
        cell.laName.text = self.dataSource[indexPath.row];
    }
    return cell;
}


#pragma mark -  <UICollectionViewDelegateFlowLayout>
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView
                        layout:(UICollectionViewLayout*)collectionViewLayout
        insetForSectionAtIndex:(NSInteger)section{
    return UIEdgeInsetsMake(self.searchBar.frame.size.height, 0, 0, 0);
}
- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout*)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath{
    CGFloat cellLeg = (self.collectionView.frame.size.width/2) - 5;
    return CGSizeMake(cellLeg,cellLeg);;
}


#pragma mark - search
- (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope{
    NSPredicate *resultPredicate    = [NSPredicate predicateWithFormat:@"self contains[c] %@", searchText];
    self.dataSourceForSearchResult  = [self.dataSource filteredArrayUsingPredicate:resultPredicate];
}

- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{
    // user did type something, check our datasource for text that looks the same
    if (searchText.length>0) {
        // search and reload data source
        self.searchBarActive = YES;
        [self filterContentForSearchText:searchText
                                   scope:[[self.searchDisplayController.searchBar scopeButtonTitles]
                                          objectAtIndex:[self.searchDisplayController.searchBar
                                                         selectedScopeButtonIndex]]];
        [self.collectionView reloadData];
    }else{
        // if text lenght == 0
        // we will consider the searchbar is not active
        self.searchBarActive = NO;
    }
}

- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar{
    [self cancelSearching];
    [self.collectionView reloadData];
}
- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar{
    self.searchBarActive = YES;
    [self.view endEditing:YES];
}
- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar{
    // we used here to set self.searchBarActive = YES
    // but we'll not do that any more... it made problems
    // it's better to set self.searchBarActive = YES when user typed something
    [self.searchBar setShowsCancelButton:YES animated:YES];
}
- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar{
    // this method is being called when search btn in the keyboard tapped
    // we set searchBarActive = NO
    // but no need to reloadCollectionView
    self.searchBarActive = NO;
    [self.searchBar setShowsCancelButton:NO animated:YES];
}
-(void)cancelSearching{
    self.searchBarActive = NO;
    [self.searchBar resignFirstResponder];
    self.searchBar.text  = @"";
}
#pragma mark - prepareVC
-(void)prepareUI{
    [self addSearchBar];
    [self addRefreshControl];
}
-(void)addSearchBar{
    if (!self.searchBar) {
        self.searchBarBoundsY = self.navigationController.navigationBar.frame.size.height + [UIApplication sharedApplication].statusBarFrame.size.height;
        self.searchBar = [[UISearchBar alloc]initWithFrame:CGRectMake(0,self.searchBarBoundsY, [UIScreen mainScreen].bounds.size.width, 44)];
        self.searchBar.searchBarStyle       = UISearchBarStyleMinimal;
        self.searchBar.tintColor            = [UIColor whiteColor];
        self.searchBar.barTintColor         = [UIColor whiteColor];
        self.searchBar.delegate             = self;
        self.searchBar.placeholder          = @"search here";

        [[UITextField appearanceWhenContainedIn:[UISearchBar class], nil] setTextColor:[UIColor whiteColor]];

        // add KVO observer.. so we will be informed when user scroll colllectionView
        [self addObservers];
    }

    if (![self.searchBar isDescendantOfView:self.view]) {
        [self.view addSubview:self.searchBar];
    }
}

-(void)addRefreshControl{
    if (!self.refreshControl) {
        self.refreshControl                  = [UIRefreshControl new];
        self.refreshControl.tintColor        = [UIColor whiteColor];
        [self.refreshControl addTarget:self
                                action:@selector(refreashControlAction)
                      forControlEvents:UIControlEventValueChanged];
    }
    if (![self.refreshControl isDescendantOfView:self.collectionView]) {
        [self.collectionView addSubview:self.refreshControl];
    }
}
-(void)startRefreshControl{
    if (!self.refreshControl.refreshing) {
        [self.refreshControl beginRefreshing];
    }
}

#pragma mark - observer 
- (void)addObservers{
    [self.collectionView addObserver:self forKeyPath:@"contentOffset" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];
}
- (void)removeObservers{
    [self.collectionView removeObserver:self forKeyPath:@"contentOffset" context:Nil];
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(UICollectionView *)object change:(NSDictionary *)change context:(void *)context{
    if ([keyPath isEqualToString:@"contentOffset"] && object == self.collectionView ) {
        self.searchBar.frame = CGRectMake(self.searchBar.frame.origin.x,
                                          self.searchBarBoundsY + ((-1* object.contentOffset.y)-self.searchBarBoundsY),
                                          self.searchBar.frame.size.width,
                                          self.searchBar.frame.size.height);
    }
}


@end

Answer 1

通過檢查屬性檢查器下的節標題，可以在故事板中添加標題：

您還需要在集合視圖數據源中實現以下方法：

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
    UICollectionReusableView *view = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"header" forIndexPath:indexPath];
    return view;
}

其中標識符也在故事板中設置為標題。

頭部高度可以通過委托方法控制：

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
    return CGSizeMake(0, 80);
}

這是故事板的外觀：

當您手動添加搜索欄時，您可能無法獲得正確的布局。 可以在故事板中添加搜索欄。 如果您選擇在故事板中添加搜索欄，您將不得不重新構建您的視圖，包括您的集合視圖，以便它們包含在父視圖中。 否則，您必須手動操作約束以獲得搜索欄的正確定位。

Answer 2

@Daniel Zhang說，您以垂直方式滾動。 所以你不能使用 x 軸來改變位置。但是你可以做一件事......做步驟：

1. Add the code @Daniel Zhang suggest and do
2. In story board make the header size height = 80, then place the label over there.

3. Then add constraint (i.e as you want where to place your header title).Then give background color for label. so that it will show different from your cell,searchbar.
4. Make you cell top = 0. You can do when you click your collection view & move to size inspector.

就是這樣，運行看看你會看到你的標題與單元格，搜索欄不同。

試試這個對我有用。如果它不起作用。嘗試查看這個演示項目，他們使用故事板使用搜索欄