iOS探索之從拍照中獲取圖像對應的ALAsset

    if(nil == _library)

        _library = [[ALAssetsLibrary alloc] init];

    __weak __typeof__(self) weakSelf = self;

    [_library writeImageToSavedPhotosAlbum:[savedImage CGImage] orientation:(ALAssetOrientation)[savedImage imageOrientation] completionBlock:^(NSURL *assetURL, NSError *error){

        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0),^{

            [weakSelf.library assetForURL:assetURL resultBlock:^(ALAsset *asset){//這裏的asset即是咱們所須要的圖像對應的ALAsset了

                dispatch_async(dispatch_get_main_queue(),^{

   

                });

            }failureBlock:nil];

        });

    }];