- (void)saveToAlbumWithMetadata:(NSDictionary*)metadata                      imageData:(NSData*)imageData                customAlbumName:(NSString*)customAlbumName                completionBlock:(void(^)(void))completionBlock                   failureBlock:(void(^)(NSError*error))failureBlock{    ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc] init];
    //接下来是疯狂的 block    void(^AddAsset)(ALAssetsLibrary *, NSURL*) = ^(ALAssetsLibrary *assetsLibrary, NSURL*assetURL) {
        //1 遍历 AssetsLibrary 整个相册库        [assetsLibrary assetForURL:assetURL resultBlock:^(ALAsset *asset) {
　　　　　　　//2 遍历 ALAssetsGroup 相册库中文件夹            [assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL*stop) {
                //3 找到 customAlbumName 对应的相册库文件夹                if([[group valueForProperty:ALAssetsGroupPropertyName] isEqualToString:customAlbumName]) {                    [group addAsset:asset];                    if(completionBlock) {                        completionBlock();                    }                }            } failureBlock:^(NSError*error) {                if(failureBlock) {                    failureBlock(error);                }            }];        } failureBlock:^(NSError*error) {            if(failureBlock) {                failureBlock(error);            }        }];    };

    //把照片写入相册    [assetsLibrary writeImageDataToSavedPhotosAlbum:imageData metadata:metadata completionBlock:^(NSURL*assetURL, NSError*error) {        if(customAlbumName) {            [assetsLibrary addAssetsGroupAlbumWithName:customAlbumName resultBlock:^(ALAssetsGroup *group) {                if(group) {                    [assetsLibrary assetForURL:assetURL resultBlock:^(ALAsset *asset) {                        [group addAsset:asset];                        if(completionBlock) {                            completionBlock();                        }                    } failureBlock:^(NSError*error) {                        if(failureBlock) {                            failureBlock(error);                        }                    }];                }else{                    AddAsset(assetsLibrary, assetURL);                }            } failureBlock:^(NSError*error) {                AddAsset(assetsLibrary, assetURL);            }];        }else{            if(completionBlock) {                completionBlock();            }        }    }];     } - (void)saveImage:(UIImage*)image{    ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc] init];    NSMutableArray*groups=[[NSMutableArrayalloc]init];    ALAssetsLibraryGroupsEnumerationResultsBlock listGroupBlock = ^(ALAssetsGroup *group, BOOL*stop)    {        if(group)        {            [groups addObject:group];        }        else        {            BOOLhaveHDRGroup = NO;                         for(ALAssetsGroup *gp in groups)            {                NSString*name =[gp valueForProperty:ALAssetsGroupPropertyName];                                 if([name isEqualToString:@"Flickr墙纸"])                {                    haveHDRGroup = YES;                }            }                         if(!haveHDRGroup)            {                //do add a group named "HDR"                [assetsLibrary addAssetsGroupAlbumWithName:@"Flickr墙纸"                                               resultBlock:^(ALAssetsGroup *group)                 {                     [groups addObject:group];                                       }                                              failureBlock:nil];                haveHDRGroup = YES;            }        }             };    //创建相簿    [assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAlbum usingBlock:listGroupBlock failureBlock:nil];     

//在我的"扫一扫"代码中，生成的二维码图片存到新创建的相薄后显示全黑，后同事指点原来是下边红色方法的问题，后换了个方法实现了：UIImageJPEGRepresentation(image,1)    [self saveToAlbumWithMetadata:nilimageData:UIImagePNGRepresentation(image) customAlbumName:@"Flickr墙纸"completionBlock:^    {        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"保存成功"message:@"若想马上启用该墙纸，请进入图库找到该墙纸并设置为墙纸即可，感谢您的使用。"delegate:nilcancelButtonTitle:@"好"otherButtonTitles: nil];        [alert show];             } failureBlock:^(NSError*error)    {        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"保存失败"message:error.description delegate:nilcancelButtonTitle:@"知道了"otherButtonTitles: nil];        [alert show];//面这个方法可判断是否是因为用户拒绝访问地址所致，如果是中文环境返回 的是“用户拒绝访问”if (([myerror.localizedDescription rangeOfString:@"User denied access"].location!=NSNotFound ）|| （[myerror.localizedDescription rangeOfString:@"用户拒绝访问"].location!=NSNotFound）)    }]; }