How does iOS cache images and iOS images?

How does iOS cache images and iOS images?

How does iOS cache images?

In iOS development, it is common to get images from the network. If we load a lot of images, we should add cache to the images so that the next time we can quickly read the images, improve Efficiency

Note: Only one view is created, and no other attributes are written.

1. Normal image loading method (no cache ):

UIImageView * imageView = [[UIImageView alloc]init];    imageView.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://su.bdimg.com/static/superplus/img/logo_white_ee663702.png"]]];

2. You can use a third-party library SDWebImage to add a cache for images.

Download the latest SDWebImage and drag them to the project to import # import "UIImageView + WebCache. h "is introduced into the project. The following example adds a cache to the image. The first time the cache is slow, it will soon become available.

[imageView setImageWithURL:[NSURL URLWithString:@"http://su.bdimg.com/static/superplus/img/logo_white_ee663702.png"] placeholderImage:[UIImage imageNamed:@"1.png"]];

PlaceholderImage: [UIImage imageNamed: @ "1.png"]. Here is a backup image that has not been loaded.