我是UICollectionViews的新手，我想知道如何做到这一点，以便在滚动UICollectionView时以下代码不会重绘自身？
最初滚动时效果很好，但是当您重新滚动时，它将再次绘制自身，并且彼此之间出现重复项。
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"cellIdentifier" forIndexPath:indexPath];
UIView *tmpView;
if([self.selectedEffects isEqualToString:@"Effects"]){
int index = indexPath.row;
NSLog(@"%i",index);
tmpView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 70, 90)];
[tmpView setBackgroundColor:[UIColor clearColor]];
UIImageView *imageViewWithEffect = [[UIImageView alloc] initWithFrame:CGRectMake(5, 0, 60, 60)];
imageViewWithEffect.layer.cornerRadius = 10.00;
imageViewWithEffect.clipsToBounds = YES;
UILabel *labelEffect = [[UILabel alloc] initWithFrame:CGRectMake(0, 65, 70, 20)];
[labelEffect setText:[[self.activeEffectsArray objectAtIndex:index] objectAtIndex:1]];
labelEffect.textAlignment = NSTextAlignmentCenter;
labelEffect.textColor = [UIColor whiteColor];
[labelEffect setFont:[UIFont boldSystemFontOfSize:8]];
UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
[activityIndicator setFrame:CGRectMake(0, 0, 60, 60)];
activityIndicator.alpha = 1.0;
[activityIndicator startAnimating];
UIButton *buttonSelect = [UIButton buttonWithType:UIButtonTypeCustom];
[buttonSelect setFrame:CGRectMake(0, 0, 60, 90)];
[buttonSelect setTag:index];
[buttonSelect addTarget:self action:@selector(applyEffects:) forControlEvents:UIControlEventTouchUpInside];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
UIImage *imageWithEffect = [self editImage:[[self.activeEffectsArray objectAtIndex:indexPath.row] objectAtIndex:0] ImageToEdit:self.thumbnailImage];
dispatch_async(dispatch_get_main_queue(), ^{
[imageViewWithEffect setImage:imageWithEffect];
[activityIndicator removeFromSuperview];
});
});
[tmpView addSubview:imageViewWithEffect];
[tmpView addSubview:labelEffect];
[tmpView addSubview:activityIndicator];
[tmpView addSubview:buttonSelect];
}
if([self.selectedEffects isEqualToString:@"Frames"]){
int index = indexPath.row;
tmpView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 70, 90)];
[tmpView setBackgroundColor:[UIColor clearColor]];
UIImageView *imageViewWithEffect = [[UIImageView alloc] initWithFrame:CGRectMake(5, 0, 60, 60)];
UILabel *labelEffect = [[UILabel alloc] initWithFrame:CGRectMake(0, 65, 70, 20)];
[labelEffect setText:[[self.activeFrameArray objectAtIndex:index] objectAtIndex:1]];
labelEffect.textAlignment = NSTextAlignmentCenter;
labelEffect.textColor = [UIColor whiteColor];
[labelEffect setFont:[UIFont boldSystemFontOfSize:10]];
UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
[activityIndicator setFrame:CGRectMake(0, 0, 60, 60)];
activityIndicator.alpha = 1.0;
[activityIndicator startAnimating];
UIButton *buttonSelect = [UIButton buttonWithType:UIButtonTypeCustom];
[buttonSelect setFrame:CGRectMake(0, 0, 60, 90)];
[buttonSelect setTag:index];
[buttonSelect addTarget:self action:@selector(applyFrames:) forControlEvents:UIControlEventTouchUpInside];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
UIImage *imageWithEffect = [self applyFrame:[[self.activeFrameArray objectAtIndex:indexPath.row] objectAtIndex:0] ImageToEdit:self.thumbnailImage];
dispatch_async(dispatch_get_main_queue(), ^{
[imageViewWithEffect setImage:imageWithEffect];
[activityIndicator removeFromSuperview];
});
});
[tmpView addSubview:imageViewWithEffect];
[tmpView addSubview:labelEffect];
[tmpView addSubview:activityIndicator];
[tmpView addSubview:buttonSelect];
}
[cell addSubview:tmpView];
return cell;
}
谢谢
最佳答案
似乎更好的方法是使用UICollectionViewCell子类，也许是ORSEffectsCell
在子类内部，您将配置适当的视图层次结构，然后为这些视图提供访问器。
然后，这意味着您将创建一次单元视图层次结构，然后重新配置每个单元的内容。
关于ios - UICollectionView重绘到自身上，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/21797158/