[[PHImageManager defaultManager] requestImageForAsset:asset targetSize:CGSizeMake(200, 200) contentMode:PHImageContentModeAspectFill options:options resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
//此处result会渲染，导致内存极高，然会发生崩溃
}];
[[PHImageManager defaultManager] requestImageDataForAsset:asset options:options resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
//将其由data转换为image就可以解决内存占有率过高的问题
UIImage * result = [UIImage imageWithData:imageData];
}];
