二:在手机相册(ios设备相册)中创建相册
第一步:向工程里添加AssetsLibrary 库文件
第二步:在项目中"import" 导入库(在哪用就在哪导入)
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#import <AssetsLibrary/AssetsLibrary.h> |
核心代码
在需要添加相册的地方调用代码
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//添加到相册我让它执行是异步执行的方式,如果不想用这种方式,可以不去开一个线程 dispatch_async(dispatch_get_global_queue(0, 0), ^{
[self createAlbumInPhoneAlbum];
}); |
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#pragma mark - 在手机相册中创建相册 - (void)createAlbumInPhoneAlbum { ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc] init]; NSMutableArray *groups=[[NSMutableArray alloc]init]; ALAssetsLibraryGroupsEnumerationResultsBlock listGroupBlock = ^(ALAssetsGroup *group, BOOL *stop) { if (group) { [groups addObject:group]; }
else { BOOL haveHDRGroup = NO;
for (ALAssetsGroup *gp in groups) { NSString *name =[gp valueForProperty:ALAssetsGroupPropertyName];
if ([name isEqualToString:@"相册名字"]) { haveHDRGroup = YES; } }
if (!haveHDRGroup) { //do add a group named "XXXX" [assetsLibrary addAssetsGroupAlbumWithName:@"相册名字" resultBlock:^(ALAssetsGroup *group) { [groups addObject:group];
} failureBlock:nil]; haveHDRGroup = YES; } }
}; //创建相簿 [assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAlbum usingBlock:listGroupBlock failureBlock:nil];
[self saveToAlbumWithMetadata:nil imageData:UIImagePNGRepresentation(self.imageView.image) customAlbumName:@"相册名字" completionBlock:^ { //这里可以创建添加成功的方法
} failureBlock:^(NSError *error) { //处理添加失败的方法显示alert让它回到主线程执行,不然那个框框死活不肯弹出来 dispatch_async(dispatch_get_main_queue(), ^{
//添加失败一般是由用户不允许应用访问相册造成的,这边可以取出这种情况加以判断一下 if([error.localizedDescription rangeOfString:@"User denied access"].location != NSNotFound ||[error.localizedDescription rangeOfString:@"用户拒绝访问"].location!=NSNotFound){
UIAlertView *alert=[[UIAlertView alloc]initWithTitle:error.localizedDescription message:error.localizedFailureReason delegate:nil cancelButtonTitle:NSLocalizedString(@"ok", nil) otherButtonTitles: nil];
[alert show]; [alert release];
} }); }]; }
- (void)saveToAlbumWithMetadata:(NSDictionary *)metadata imageData:(NSData *)imageData customAlbumName:(NSString *)customAlbumName completionBlock:(void (^)(void))completionBlock failureBlock:(void (^)(NSError *error))failureBlock {
ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc] init]; void (^AddAsset)(ALAssetsLibrary *, NSURL *) = ^(ALAssetsLibrary *assetsLibrary, NSURL *assetURL) { [assetsLibrary assetForURL:assetURL resultBlock:^(ALAsset *asset) { [assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
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); } }]; }; [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(); } } }]; } |
三、ALAssetsLibrary、ALAssetsGroup、ALAsset 介绍
1、ALAssetsLibrary
ALAssetsLibrary提供了我们对iOS设备中的相片、视频的访问。它是连接了我们应用程序和相册之间的访问的一个桥梁。
2、ALAssetsGroup
指代一个相册。
3、ALAsset
每一个ALAsset代表一个单一资源文件(也就是一张图片,或者一个视频文件)
4、ALAssetRepresentation
ALAssetRepresentation封装了ALAsset,包含了一个资源文件中的很多属性。(可以说是ALAsset的不同的表示方式,本质上都表示同一个资源文件)