沙盒路径获取以及图片保存到相簿的方法

// 获取沙盒主目录路径 
NSString *homeDir = NSHomeDirectory(); 
// 获取Documents目录路径 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *docDir = [paths objectAtIndex:0]; 
// 获取Caches目录路径 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES); 
NSString *cachesDir = [paths objectAtIndex:0]; 
// 获取tmp目录路径 
NSString *tmpDir = NSTemporaryDirectory(); 
// 获取当前程序包中一个图片资源（apple.png）路径 
NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"apple" ofType:@"png"]; 
UIImage *appleImage = [[UIImage alloc] initWithContentsOfFile:imagePath]; 

- (void)loadImageFinished:(UIImage *)image
{
 UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), (__bridge void *)self);
}
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
 NSLog(@"image = %@, error = %@, contextInfo = %@", image, error, contextInfo);
}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo;

- (void)loadImageFinished:(UIImage *)image
{
 __block ALAssetsLibrary *lib = [[ALAssetsLibrary alloc] init];
 [lib writeImageToSavedPhotosAlbum:image.CGImage metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {
  NSLog(@"assetURL = %@, error = %@", assetURL, error);
  lib = nil;
 }];
}

- (void)loadImageFinished:(UIImage *)image
{
 [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
   /写入图片到相册
   PHAssetChangeRequest *req = [PHAssetChangeRequest creationRequestForAssetFromImage:image];

  } completionHandler:^(BOOL success, NSError * _Nullable error) {
   NSLog(@"success = %d, error = %@", success, error);
 }];
}

- (void)loadImageFinished:(UIImage *)image
{
 NSMutableArray *imageIds = [NSMutableArray array];
  [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
   //写入图片到相册
   PHAssetChangeRequest *req = [PHAssetChangeRequest creationRequestForAssetFromImage:image];
   //记录本地标识，等待完成后取到相册中的图片对象
   [imageIds addObject:req.placeholderForCreatedAsset.localIdentifier];

  } completionHandler:^(BOOL success, NSError * _Nullable error) {
   NSLog(@"success = %d, error = %@", success, error);
   if (success)
   {
    //成功后取相册中的图片对象
    __block PHAsset *imageAsset = nil;
    PHFetchResult *result = [PHAsset fetchAssetsWithLocalIdentifiers:imageIds options:nil];
    [result enumerateObjectsUsingBlock:^(PHAsset * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
     imageAsset = obj;
     *stop = YES;
    }];
    if (imageAsset)
    {
     //加载图片数据
     [[PHImageManager defaultManager] requestImageDataForAsset:imageAsset
       options:nil
       resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
        NSLog("imageData = %@", imageData);
       }];
    }
   }
  }];
}