将图像保存到文档目录不再适用于iOS8

Question

将图像保存到文档目录似乎不再适用于iOS8。我听说有Changes To App Containers In iOS 8。但我似乎仍然无法让我的代码工作。我将图像保存到文档目录，稍后检索以使用。这是我在图像目录中保存图像的代码;

-(void) simpleCam:(SimpleCam *)simpleCam didFinishWithImage:(UIImage *)image {

if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
    //choose Photo

}else{

    if (image) {

        //save the image to photos library
        UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);

        NSData *imageData = UIImageJPEGRepresentation(image,1);

        // Get image path in user's folder and store file with name image_CurrentTimestamp.jpg (see documentsPathForFileName below)
        NSString *imagePath = [self documentsPathForFileName:[NSString stringWithFormat:@"image_%f.jpg", [NSDate timeIntervalSinceReferenceDate]]];


        // Write image data to user's folder
        [imageData writeToFile:imagePath atomically:YES];

        // Store path in NSUserDefaults
        [[NSUserDefaults standardUserDefaults] setObject:imagePath forKey:[NSString stringWithFormat:@"%@%@",kImageDataKey,self.accessToken]];

        // Sync user defaults
        [[NSUserDefaults standardUserDefaults] synchronize];
    }
}

我的documentsPathForFileName方法;

- (NSString *)documentsPathForFileName:(NSString *)name {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];

return [documentsPath stringByAppendingPathComponent:name];
}

图像路径返回空，但在iOS7中完美运行。