How to go back to RootViewController from presentView controller?

Question

I am developing a iPhone Photos Gallery app and In my app I created one folder into gallery and that gallery folder is shown up into my app and while use click on Image its

Answer 1

I found solution for my question is :

 @IBAction func btnTrash(sender: AnyObject) {

    let alert = UIAlertController(title: "Delete Image", message: "Are You Sure To delete this Image?", preferredStyle: .Alert)
    alert.addAction(UIAlertAction(title: "Yes", style: .Default, handler: {(alertAction)in
        //Delete Photo

        PHPhotoLibrary.sharedPhotoLibrary().performChanges({
            let request = PHAssetCollectionChangeRequest(forAssetCollection: self.assetCollection)
            request.removeAssets([self.photosAsset[self.index]])
            }, completionHandler: {(success, error )in
                NSLog("\nDeleted Image -> %@", (success ? "Success" : "Error"))

                alert.dismissViewControllerAnimated(true, completion: nil)

                // here is the code for go back to root view controller

                if(success){
                    // Move to the main thread to execute
                    dispatch_async(dispatch_get_main_queue(), {
                        self.photosAsset = PHAsset.fetchAssetsInAssetCollection(self.assetCollection, options: nil)
                        if(self.photosAsset.count == 0){
                            println("No Images Left!!")
                            self.navigationController?.popToRootViewControllerAnimated(true)
                        }else{
                            if(self.index >= self.photosAsset.count){
                                self.index = self.photosAsset.count - 1
                            }
                            self.displayPhoto()
                        }
                    })
                }else{
                    println("Error: \(error)")
                }
        })


    }))
    alert.addAction(UIAlertAction(title: "Cancle", style: .Cancel, handler: {(alertAction)in
    //Do not delete Photo

    self.dismissViewControllerAnimated(true, completion: nil)
    }))
    self.presentViewController(alert, animated: true, completion: nil)
}