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：
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：
保存照片至相册：
-(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];
}];
}
增加图片至自定义相册：
-(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) {
//target album is found
albumWasFound = YES;
//get a hold of the photo's asset instance
[self assetForURL: assetURL
resultBlock:^(ALAsset *asset) {
//add photo to the target album
[group addAsset: asset];
//run the completion block
completionBlock(nil);
} failureBlock: completionBlock];
//album was found, bail out of the method
return;
}
if (group==nil && albumWasFound==NO) {
//photo albums are over, target album does not exist, thus create it
__weak ALAssetsLibrary* weakSelf = self;
//create new assets album
[self addAssetsGroupAlbumWithName:albumName
resultBlock:^(ALAssetsGroup *group) {
//get the photo's instance
[weakSelf assetForURL: assetURL
resultBlock:^(ALAsset *asset) {
//add photo to the newly created album
[group addAsset: asset];
//call the completion block
completionBlock(nil);
} failureBlock: completionBlock];
} failureBlock: completionBlock];
//should be the last iteration anyway, but just in case
return;
}
} failureBlock: completionBlock];
}
如何添加分组：
[[DataCenter defaultAssetsLibrary] addAssetsGroupAlbumWithName:[alertView textFieldAtIndex:0].text
resultBlock:resulBlock
failureBlock:nil];