Question

我在UICollectionView中显示文章，并带有一个按钮，用于打开WYPopoverController，用户可以放大图像。

为避免两次下载图像，我试图将图像从UICollectionView传递到popover，但它无法正常工作：

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    LOArcticlesCustomCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"MyCell" forIndexPath:indexPath];

    [cell.imageView setImageWithURL:[NSURL URLWithString:[[articlesArray objectAtIndex:indexPath.row]objectForKey:@"photoUrl"]]placeholderImage:[UIImage imageNamed:@"simboloLakari29.png"]];


    index= indexPath.row;

    self.imageArticle = cell.imageView.image;
    self.imageUrl = [NSString stringWithString:[[articlesArray objectAtIndex:indexPath.row]objectForKey:@"photoUrl"]];
    cell.lblMake.text = [NSString stringWithString:[[articlesArray objectAtIndex:indexPath.row]objectForKey:@"marca"]];
    cell.lblMake.lineBreakMode = NSLineBreakByWordWrapping;
    cell.lblModel.text = [NSString stringWithString:[[articlesArray objectAtIndex:indexPath.row]objectForKey:@"modelo"]];
    cell.lblModel.lineBreakMode = NSLineBreakByWordWrapping;
    cell.lblPrice.text = [NSString stringWithString:[[articlesArray objectAtIndex:indexPath.row]objectForKey:@"precio"]];
    cell.lblOrder.text = [NSString stringWithFormat:@"%ld de %ld", (unsigned long)indexPath.row+1, (unsigned long)articlesArray.count];

    //button magnify position
    CGFloat screenHeight = [[UIScreen mainScreen] bounds].size.height;
    if (screenHeight == 568) {
        cell.magnify.frame = CGRectMake(145.0, 418.0, 30.0, 30.0);
        cell.imageView.frame = CGRectMake(20.0, 45.0, 260.0, 260.0);
    }

    return cell;
}


- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"biggerPicture"])
    {

        WYStoryboardPopoverSegue* popoverSegue = (WYStoryboardPopoverSegue*)segue;

        LOBiggerPictureViewController* destinationViewController = (LOBiggerPictureViewController *)segue.destinationViewController;


        destinationViewController.preferredContentSize = CGSizeMake(320, 320);
        destinationViewController.imageDownloaded = self.imageArticle;


        popoverController = [popoverSegue popoverControllerWithSender:sender permittedArrowDirections:WYPopoverArrowDirectionAny animated:YES];
        popoverController.delegate = self;
        WYPopoverBackgroundView* appearance = [WYPopoverBackgroundView appearance];
        [appearance setTintColor:[UIColor redColor]];

       UIColor* popColor = [UIColor colorWithRed:126/255.0 green:34/255.0 blue:110/255.0 alpha:1.0];


        WYPopoverBackgroundView* popoverAppearance = [WYPopoverBackgroundView appearance];

        [popoverAppearance setOuterCornerRadius:4];
        [popoverAppearance setOuterShadowBlurRadius:1];
        [popoverAppearance setOuterShadowColor:[UIColor darkGrayColor]];
        [popoverAppearance setOuterShadowOffset:CGSizeMake(1, 1)];

        [popoverAppearance setGlossShadowColor:[UIColor lightGrayColor]];
        [popoverAppearance setGlossShadowOffset:CGSizeMake(1, 1)];

        [popoverAppearance setBorderWidth:8];
        [popoverAppearance setArrowHeight:10];
        [popoverAppearance setArrowBase:20];

        [popoverAppearance setInnerCornerRadius:4];
        [popoverAppearance setInnerShadowBlurRadius:0];
        [popoverAppearance setInnerShadowColor:[UIColor darkTextColor]];
        [popoverAppearance setInnerShadowOffset:CGSizeMake(1, 1)];

        [popoverAppearance setFillTopColor:popColor];
        [popoverAppearance setFillBottomColor:popColor];
        [popoverAppearance setOuterStrokeColor:popColor];
        [popoverAppearance setInnerStrokeColor:popColor];
        UINavigationBar* navBarInPopoverAppearance = [UINavigationBar appearanceWhenContainedIn:[UINavigationController class], [WYPopoverController class], nil];
        [navBarInPopoverAppearance setTitleTextAttributes: @{
                                                             NSForegroundColorAttributeName  : [UIColor clearColor],
                                                             NSShadowAttributeName : [UIColor lightGrayColor],
                                                             NSShadowAttributeName : [NSValue valueWithUIOffset:UIOffsetMake(0, -1)]}];
    }

}

在popover中：

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

      [self.imageView performSelectorOnMainThread:@selector(setImage:) withObject:imageDownloaded waitUntilDone:YES];

    [self.imageView sizeToFit];
    self.scrollView.contentSize =self.image.size;
    self.scrollView.delegate = self;
    self.scrollView.minimumZoomScale   =  1.0;
    self.scrollView.maximumZoomScale    = 3.0;

}

NSLog显示一个空对象。有什么问题？

Answer 1

故事板中的弹出窗口在Xcode 6中有点被弃用。首先要检查的是你的弹出窗口，看看“segue”下拉是否显示为“Popover”或“Present as Popover”。我相信“Popover”有些东西在iOS8上已经停止正常工作。

如果您的应用能够使用，只需将其更改为“呈现为弹出窗口”即可解决此问题。如果您没有该选项，请检查故事板（第一个选项卡）的“文件检查器”部分中的“使用大小类”框，以启用新的弹出窗口。

Answer 2

尝试在 viewWillAppear 中设置图像，而不是 viewDidLoad 。我认为该变量尚未由 prepareforSegue 设置。

WYPopoverController：如何将图像传递给弹出窗口

2 个答案: