iOS项目 瀑布流 实现
一直对于collectionview处于半懂不懂的状态
所以现在自己做了一个，实现效果如下
#import "ViewController.h"
#import "CollectionViewCell.h"
static NSString *identifierCell = @"cellID";
@interface ViewController ()<UICollectionViewDelegateFlowLayout>
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.collectionView.allowsMultipleSelection = YES;
self.collectionView.allowsSelection = YES;
self.collectionView.showsVerticalScrollIndicator = YES;
self.collectionView.backgroundColor = [UIColor grayColor];
[self registerHeaderAndFooter];
// Do any additional setup after loading the view, typically from a nib.
}
-(BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
-(void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath
{
CollectionViewCell *cell = (CollectionViewCell *)[self.collectionView cellForItemAtIndexPath:indexPath];
cell.selectedBtn.selected = NO;
[cell.selectedBtn setImage:[UIImage imageNamed:@"1"] forState:UIControlStateNormal];
}
-(void)registerHeaderAndFooter{
[self.collectionView registerNib:[UINib nibWithNibName:@"HeaderCollectionReusableView" bundle:[NSBundle mainBundle]] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"HeaderCollectionReusableView"];
[self.collectionView registerNib:[UINib nibWithNibName:@"FooterCollectionReusableView" bundle:[NSBundle mainBundle]] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"FooterCollectionReusableView"];
}
-(UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
if ([kind isEqualToString:UICollectionElementKindSectionFooter]) {
UICollectionReusableView *footer = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"FooterCollectionReusableView" forIndexPath:indexPath];
return footer;
}
UICollectionReusableView *header = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"HeaderCollectionReusableView" forIndexPath:indexPath];
return header;
}
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
return CGSizeMake(150, 150);
}
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section
{
return CGSizeMake(80, 80);
}
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section
{
return CGSizeMake(80, 80);
}
//-(BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath{
//
// return YES;
//
//
//}
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
CollectionViewCell *cell = (CollectionViewCell *)[self.collectionView cellForItemAtIndexPath:indexPath];
// cell.selectedBtn.userInteractionEnabled = NO;
cell.selectedBtn.selected = YES;
[cell.selectedBtn setBackgroundImage:[UIImage imageNamed:@"2"] forState:UIControlStateSelected];
}
-(BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView{
return 5;
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 20;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifierCell forIndexPath:indexPath];
return cell;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
关键一步
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-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{ CGFloat height=100+(arc4random()%100); return CGSizeMake(100, height);} |
@end
