iOS 之UICollectionView

-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView

-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {

　　　　static NSString * CellIdentifier = @"GradientCell";

　　　　UICollectionViewCell * cell = [collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];

　　　　cell.backgroundColor = [UIColor colorWithRed:((10 * indexPath.row) / 255.0) green:((20 * indexPath.row)/255.0) blue:((30 * indexPath.row)/255.0) alpha:1.0f];

　　　　return cell;

　　}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {  
    return CGSizeMake(96, 100);  
} 

-(UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section  {  
    return UIEdgeInsetsMake(5, 5, 5, 5);  
}  

//UICollectionView被选中时调用的方法  
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath  {  
    UICollectionViewCell * cell = (UICollectionViewCell *)[collectionView cellForItemAtIndexPath:indexPath];  
    cell.backgroundColor = [UIColor whiteColor];  
}  

-(BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath  {  
    return YES;  
}