如何将图片保存至自定义分组

一般我们照片存储都是直接存储在相机胶卷中，调用下面的方法就可以了：

[plain]
void UIImageWriteToSavedPhotosAlbum (
   UIImage *image,
   id       completionTarget,
   SEL      completionSelector,
   void     *contextInfo
);

void UIImageWriteToSavedPhotosAlbum (
   UIImage *image,
   id       completionTarget,
   SEL      completionSelector,
   void     *contextInfo
);
       但是如果我们想将图片存储到自定义的分组该怎么做呢，我查了一下ALAssetsLibrary的文档，发现没有相应的方法，好吧，google一下，发现了一篇文章：点击打开链接。

作者的解决思路如下：

1.将图片先保存到相机胶卷中；

2.在相机胶卷中找到这个图片所创建的AlAsset；

3.将此AlAsset添加到你需要存放的自定义分组中。

主要代码如下所示，注释也很清楚了：

[plain]
-(void)saveImage:(UIImage*)image toAlbum:(NSString*)albumName withCompletionBlock:(SaveImageCompletion)completionBlock
{
    //write the image data to the assets library (camera roll)
    [self writeImageToSavedPhotosAlbum:image.CGImage orientation:(ALAssetOrientation)image.imageOrientation
                        completionBlock:^(NSURL* assetURL, NSError* error) {

                          //error handling
                          if (error!=nil) {
                              completionBlock(error);
                              return;
                          }

                          //add the asset to the custom photo album
                          [self addAssetURL: assetURL
                                    toAlbum:albumName
                        withCompletionBlock:completionBlock];

                      }];
}

-(void)saveImage:(UIImage*)image toAlbum:(NSString*)albumName withCompletionBlock:(SaveImageCompletion)completionBlock
{
    //write the image data to the assets library (camera roll)
    [self writeImageToSavedPhotosAlbum:image.CGImage orientation:(ALAssetOrientation)image.imageOrientation
                        completionBlock:^(NSURL* assetURL, NSError* error) {

                          //error handling
                          if (error!=nil) {
                              completionBlock(error);
                              return;
                          }

                          //add the asset to the custom photo album
                          [self addAssetURL: assetURL
                                    toAlbum:albumName
                        withCompletionBlock:completionBlock];

                      }];
}
[plain]
-(void)addAssetURL:(NSURL*)assetURL toAlbum:(NSString*)albumName withCompletionBlock:(SaveImageCompletion)completionBlock
{
    __block BOOL albumWasFound = NO;

    //search all photo albums in the library
    [self enumerateGroupsWithTypes:ALAssetsGroupAlbum
                        usingBlock:^(ALAssetsGroup *group, BOOL *stop) {

                            //compare the names of the albums
                            if ([albumName compare: [group valueForProperty:ALAssetsGroupPropertyName]]==NSOrderedSame) {
&nbs

补充：移动开发 , IOS ,