UIImage返回零

Question

我将数据从一个控制器传递到另一个控制器.

TemplateController 发送数据的那个是这样的:

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
     PreviewController *destViewController = [[PreviewController alloc]init];
     destViewController.passFrameLabel = [self.frameImages[indexPath.section] objectAtIndex:indexPath.row];
     [self.collectionView deselectItemAtIndexPath:indexPath animated:NO];
     [destViewController loadFrame];
     [self dismissViewControllerAnimated:YES completion:nil];
}

我的loadFrame方法PreviewController看起来像这样:

UIImageView *frameImageView = [[UIImageView alloc] init];
[self.view addSubview:frameImageView];
self.frameImageView.image = [UIImage imageNamed:self.passFrameLabel];

调试后,self.passFrameLabel包含正确的值但self.frameImageView.image返回nil.我错过了什么？

Answer 1

frameImageView当您的类也具有frameImageView属性时,您似乎正在创建本地对象.您正在添加本地对象UIImageView作为子视图但是分配image给属性(似乎没有初始化).

你应该修改你的代码,

//frameImageView should be a strong property
_frameImageView = [[UIImageView alloc] init]; 
self.frameImageView.frame = CGRectMake(10,10,50,50); //Add suitable frame
//Now assign image
self.frameImageView.image = [UIImage imageNamed:self.passFrameLabel];
//Add this property as subview
[self.view addSubview:self.frameImageView];

试试看.