iOS 開發筆記 - 使用 AssetsLibrary (assets-library://) 取得相簿內照片的原圖、縮圖

一直以來都是自己檔案管理，最近開始想要用內建相簿來管理儲存。

用法：

#import <AssetsLibrary/ALAssetsLibrary.h>
#import <AssetsLibrary/AssetsLibrary.h>

typedef void (^DoneHandler)(NSDictionary *ret);
- (void)get:(NSString *)key callback:(DoneHandler)handler {
 
ALAssetsLibrary* assetslibrary = [[ALAssetsLibrary alloc] init];
 
[assetslibrary assetForURL:[NSURL URLWithString:key] resultBlock:^(ALAsset *asset) {
//NSLog(@"asset:%@",asset);
UIImage *image = nil;
image = [UIImage imageWithCGImage:[asset aspectRatioThumbnail]];
image = [UIImage imageWithCGImage:[[asset defaultRepresentation] fullResolutionImage]];
image = [UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]];
        handler(@{@"image":image});
} failureBlock:^(NSError *error) {
        handler(@{});
}];
}

其中 key 是類似這樣：assets-library://asset/asset.JPG?id=xxx&ext=JPG。