ios - UIImageView没有更新

Question

嗨，iam，当我加载该UIviewcontroller时，使用以下代码将图像加载至uiimageview，但如果我从现有的uiviewcontroller中打开任何其他uiviewcontroller并返回到旧的uiviewcontroller，并且如果单击缩略图图像，则不会更新UIimageview uiviewcontroller。

img包含图像路径(设备内部)
在viewdidload

[self setBookimage:img];

在setBookimage()中

- (void)setBookImage:(UIImage *)bookImage{

    book_cover_image.image=nil;
    book_cover_image.image = bookImage;
    CATransition *transition = [CATransition animation];
    transition.duration = 1.0f;
    transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    transition.type = kCATransitionFade;

    [book_cover_image.layer addAnimation:transition forKey:nil];
}

缩略图didselect方法代码

   - (void)thumbnailListView:(ThumbnailListView*)thumbnailListView
             didSelectAtIndex:(NSInteger)index
    {

//filePathsofimages  contains 10 image paths

//下面的代码更新图像，如果正在加载uiviewcontroller并单击缩略图，而不是打开另一个viewcontroller并返回然后单击。

     img =[[UIImage alloc]initWithContentsOfFile:[filePathsofImages objectAtIndex:index]];
                [self setBookImage:img];
    }

Answer 1

尝试:

[book_cover_image setNeedsDisplay];