iOS - UICollectionView 的自定义头视图
这里只自定义区头，区尾类似。方便起见，一个类实现：
#import "ViewController.h"
@interface ViewController ()<UICollectionViewDataSource,UICollectionViewDelegateFlowLayout>
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self creatUI];
}
#pragma mark - 方法
- (void)creatUI {
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
UICollectionView *collect = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 20, self.view.frame.size.width, self.view.frame.size.height-20) collectionViewLayout:layout];
[collect registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cell"];
/**
* 这里这个Kind必须要用常量字符串，否则会崩溃的不要不要的
*在UICollectionViewFlowLayout.h里面有
UIKIT_EXTERN NSString *const UICollectionElementKindSectionHeader NS_AVAILABLE_IOS(6_0);
UIKIT_EXTERN NSString *const UICollectionElementKindSectionFooter NS_AVAILABLE_IOS(6_0);
UIKIT_EXTERN const CGSize UICollectionViewFlowLayoutAutomaticSize NS_AVAILABLE_IOS(10_0);
*/
[collect registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"headerID"];
collect.backgroundColor = [UIColor whiteColor];
collect.delegate = self;
collect.dataSource = self;
[self.view addSubview:collect];
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
return CGSizeMake(self.view.frame.size.width, 150);
}
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 3;
}
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {
UICollectionReusableView *headerView = nil;
if (kind == UICollectionElementKindSectionHeader) {
headerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"headerID" forIndexPath:indexPath];
if (indexPath.section == 0) {
NSLog(@"这是区头0");
headerView.backgroundColor = [UIColor redColor];
}else if (indexPath.section == 1) {
NSLog(@"这是区头1");
headerView.backgroundColor = [UIColor greenColor];
}else {
NSLog(@"这是区头2");
headerView.backgroundColor = [UIColor yellowColor];
}
}
return headerView;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return 20;
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
return CGSizeMake((self.view.frame.size.width-10)/2, 100);
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
for (UIView *subView in cell.contentView.subviews) {
[subView removeFromSuperview];
}
UIView *view0 = [[UIView alloc] init];
if (indexPath.row%2==0) {
view0.frame = CGRectMake(10, 0, (self.view.frame.size.width-10)/2 - 10, 100);
}else {
view0.frame = CGRectMake(0, 0, (self.view.frame.size.width-10)/2 - 10, 100);
}
view0.backgroundColor = [UIColor cyanColor];
[cell.contentView addSubview:view0];
return cell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"第%ld个",indexPath.row);
}