Objective c IOS7风格模糊UICollectionViewCell'；s的观点随时可用

我正在尝试在点击时模糊UICollectionViewCell。我试着拍下手机的截图，然后模糊截图。使用模糊的屏幕截图作为背景并隐藏所有标签

我注意到的行为是

点击单元格1：单元格1消失

轻触单元格2：有点模糊，但我可以看出错误单元格的内容被模糊了

轻触第三单元：模糊一点

点击第四单元：大量模糊

我认为问题是：

错误的单元格内容变得模糊

当另一个单元格模糊时，模糊的屏幕截图将被重新使用，因此模糊会增加

然后我编辑了代码，将背景设置为原始的未模糊屏幕截图

点击单元格1：单元格1消失

轻触单元格2：显示单元格1的屏幕截图

轻触单元格3：显示单元格2的屏幕截图

等等

代码如下：

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
 //Code to get data from database and add to labels

  if(![[modelArray objectAtIndex:indexPath.row] isEqualToString:@"1"]){
      UIGraphicsBeginImageContextWithOptions(cell.overviewView.bounds.size, NO, cell.overviewView.window.screen.scale);
      [cell.overviewView drawViewHierarchyInRect:cell.overviewView.frame afterScreenUpdates:NO];
      UIImage *snapshotImage = UIGraphicsGetImageFromCurrentImageContext();
      UIGraphicsEndImageContext();

      snapshotImage = [snapshotImage applyLightEffect];

      cell.overviewView.backgroundColor = [UIColor colorWithPatternImage:snapshotImage];
      cell.overviewView.alpha = 1;

      cell.descLabel.alpha = 0;
      cell.dayLabel.alpha = 0;
      cell.weatherImage.alpha = 0;
      cell.tempLabel.alpha = 0;
  }


  NSLog(@"Cell :%d condition : %@", indexPath.row, weather.desc );
  return cell;
}
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
  WeekCell *cell = (WeekCell*)[collectionView cellForItemAtIndexPath:indexPath];
  NSLog(@"%@", cell.descLabel.text);
  if([[modelArray objectAtIndex:indexPath.row] isEqualToString:@"1"]){
     [modelArray setObject:@"0" atIndexedSubscript:indexPath.row];
  }else{
    [modelArray setObject:@"1" atIndexedSubscript:indexPath.row];
  }

  NSLog(@"sequence : %@", modelArray);
  [collectionView reloadItemsAtIndexPaths:@[indexPath]];

}

---

我只是发布了你可以尝试的示例代码

在自定义

UICollectionViewCell

中，我将其命名为

CustomCollectionVIewCell

，其nib文件如下所示

 - (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
 {

   CustomCollectionVIewCell *cell = (CustomCollectionVIewCell *)[collectionView cellForItemAtIndexPath:indexPath];
   UIGraphicsBeginImageContext(cell.cellImageView.bounds.size);
   [cell.forGroundView.layer renderInContext:UIGraphicsGetCurrentContext()];
   UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
   UIGraphicsEndImageContext();
   //   self.blurrImage = [image applyTintEffectWithColor:[UIColor colorWithRed:25.0f/255.0f green:77.0f/255.0f blue:108.0f/255.0f alpha:1.0f ]];
   cell.forGroundView.alpha = 0.0f;
   cell.blurImageVIew.image = [image applyLightEffect];
 }

在上面的图像中，u可以看到

视图背景视图

包含用于保存模糊图像的图像视图和

视图前景

是一个包含普通图像和两个标签的视图，一个带有绿色和黑色文本，这两个标签添加到集合视图单元，而不是任何其他视图

单元层次结构如下图所示

在代码中，将所有这些连接为单元中的插座，

CustomCollectionVIewCell.h

  @interface CustomCollectionVIewCell : UICollectionViewCell

  @property (nonatomic, assign) id<CellFooterDelegate> myCustomdelegate;//define a delegate
  @property (weak, nonatomic) IBOutlet UIView *backGroundView;
  @property (weak, nonatomic) IBOutlet UIImageView *blurImageVIew;
  @property (weak, nonatomic) IBOutlet UIView *forGroundView;
  @property (weak, nonatomic) IBOutlet UIImageView *cellImageView; 
  //..other objects

  @end

在控制器中

  -(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
 {
    CustomCollectionVIewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:cellIdentifier forIndexPath:indexPath];
    cell.myCustomdelegate = self;
    cell.cellImageView.image = [dataSourceArray objectAtIndex:indexPath.row];
    return cell;
 }

选择单元格后，u可以放置模糊图像，如下所示

 - (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
 {

   CustomCollectionVIewCell *cell = (CustomCollectionVIewCell *)[collectionView cellForItemAtIndexPath:indexPath];
   UIGraphicsBeginImageContext(cell.cellImageView.bounds.size);
   [cell.forGroundView.layer renderInContext:UIGraphicsGetCurrentContext()];
   UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
   UIGraphicsEndImageContext();
   //   self.blurrImage = [image applyTintEffectWithColor:[UIColor colorWithRed:25.0f/255.0f green:77.0f/255.0f blue:108.0f/255.0f alpha:1.0f ]];
   cell.forGroundView.alpha = 0.0f;
   cell.blurImageVIew.image = [image applyLightEffect];
 }

取消选择后，只需更改前景视图的alpha

 - (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath
 {
    CustomCollectionVIewCell *cell = (CustomCollectionVIewCell *)[collectionView cellForItemAtIndexPath:indexPath];
    cell.blurImageVIew.image = nil;
    cell.forGroundView.alpha = 1.0f;
 }

我们会像下面一样

 - (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
 {

   CustomCollectionVIewCell *cell = (CustomCollectionVIewCell *)[collectionView cellForItemAtIndexPath:indexPath];
   UIGraphicsBeginImageContext(cell.cellImageView.bounds.size);
   [cell.forGroundView.layer renderInContext:UIGraphicsGetCurrentContext()];
   UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
   UIGraphicsEndImageContext();
   //   self.blurrImage = [image applyTintEffectWithColor:[UIColor colorWithRed:25.0f/255.0f green:77.0f/255.0f blue:108.0f/255.0f alpha:1.0f ]];
   cell.forGroundView.alpha = 0.0f;
   cell.blurImageVIew.image = [image applyLightEffect];
 }

---

希望这对你有帮助：）

你需要什么？你能分享一张图片吗？@Bhaskar添加了一张图片谢谢@Shan，很好的解释。非常感谢。