解决方法
这是怎么做到的,但是我必须警告你这是缓慢的(ish)和框架所需要的这是内存密集型,因为它遍历ALAssetsLibrary寻找海报图像.
这在后台线程上,所以UI更改被发送到主线程进行渲染.
这在后台线程上,所以UI更改被发送到主线程进行渲染.
self.assetsLibrary = [[ALAssetsLibrary alloc] init];
NSUInteger groupTypes = ALAssetsGroupAlbum | ALAssetsGroupSavedPhotos | ALAssetsGroupPhotoStream;
[self.assetsLibrary enumerateGroupsWithTypes:groupTypes
usingBlock:^(ALAssetsGroup *group,BOOL *stop) {
if (group.posterImage != nil) {
dispatch_async(dispatch_get_main_queue(),^{
self.pictureLayer.contents = (__bridge_transfer id) CGImageCreateCopy(group.posterImage);
[self.layer setNeedsDisplay];
self.assetsLibrary = nil;
*stop = YES;
});
}
}
failureBlock:^(NSError *error) {
self.assetsLibrary = nil;
NSLog(@"AssetLib error:%@",error);
}];
