如何在下方顶部的集合视图中为部分添加标题 [英] how to add Header for section in collection view on top below
本文介绍了如何在下方顶部的集合视图中为部分添加标题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在使用带有搜索栏的集合视图.我已经通过 cod 添加了搜索栏，从顶部 (0,0) 开始.所以现在我的图像看起来像这样:
I am using collection view with search bar. i Have added search bar via cod with (0,0) orgin from top . so now my image look like this:
[![在此处输入图片描述][1]][1]
[![enter image description here][1]][1]
但我需要在我的搜索栏下方找到标题.我是通过故事板做的.但是在运行我的标题名称时搜索栏位于同一来源.我需要将标题部分放在 myseaarch 栏下方.
But i need to header below to my search bar . i did via story board.But while run my header name & search bar are in same orgin.I need to place my header section at below myseaarch bar.
注意:我正在唱 3 节标题.任何想法或代码都非常有帮助.
这是我的搜索栏代码...
Here my code for search bar...
#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
推荐答案
通过在属性检查器下勾选Section Header，可以在storyboard中添加标题:
The header can be added in the storyboard by checking Section Header under the attribute inspector:
您还需要在您的集合视图数据源中实现以下方法:
You also need to implement the following method in your collection view data source:
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
UICollectionReusableView *view = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"header" forIndexPath:indexPath];
return view;
}
其中标识符也在故事板中为标题设置.
where the identifier is also set in the storyboard for the header.
header高度可以通过delegate方法控制:
The header height can be controlled by the delegate method:
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
return CGSizeMake(0, 80);
}
故事板的外观如下:
当您手动添加搜索栏时，您可能无法获得正确的布局.可以在故事板中添加搜索栏.如果您选择在故事板中添加搜索栏，您将不得不重新构建您的视图，包括您的集合视图，以便它们包含在父视图中.否则，您必须手动操作约束以获得搜索栏的正确定位.
You may have trouble obtaining the correct layout as you are manually adding the search bar. The search bar can be added in the storyboard. If you choose to add the search bar in the storyboard, you will have to re-structure your views, including your collection view, so that they are contained in a parent view. Otherwise, you have to manually manipulate the constraints to get the correct positioning for the search bar.
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