pragma mark - UICollectionViewDelegate

// 允许选中时，高亮

- (BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
  return YES;  
}  

// 高亮完成后回调

- (void)collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
}  

// 由高亮转成非高亮完成时的回调

- (void)collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
}  

// 设置是否允许选中

- (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
  return YES;  
}  

// 设置是否允许取消选中

- (BOOL)collectionView:(UICollectionView *)collectionView shouldDeselectItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
  return YES;  
}  

// 选中操作

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
}  

// 取消选中操作

- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {  
  NSLog(@"%s", __FUNCTION__);  
}

/**************修改选中cell的背景颜色*******************/

/选中时的操作
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = (UICollectionViewCell *)[collectionView cellForItemAtIndexPath:indexPath];
    cell.backgroundColor = KDefaultColor;
    //选中之后的cell变颜色
    [self updateCellStatus:cell selected:YES];
}

//取消选中操作
- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath
{
     UICollectionViewCell *cell = (UICollectionViewCell *)[collectionView cellForItemAtIndexPath:indexPath];
   [self updateCellStatus:cell selected:NO];
}
// 改变cell的背景颜色
-(void)updateCellStatus:(UICollectionViewCell *)cell selected:(BOOL)selected
{
    cell.backgroundColor = selected ? KDefaultColor:[UIColor whiteColor];
    
    cell.layer.borderWidth = selected ? 0:1.0;
}