Saving image to Documents directory and retrieving for email attachment

- (IBAction)getImage {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *getImagePath = [documentsDirectory stringByAppendingPathComponent:@"savedImage.png"];
    UIImage *img = [UIImage imageWithContentsOfFile:getImagePath];
}

This should get you started!

Swift 3

// Create a URL
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first
let imageURL = documentsURL?.appendingPathComponent("MyImageName.png")

// save image to URL
let myImage = imageView.image! // or wherever you have your UIImage

do {
    try UIImagePNGRepresentation(myImage)?.write(to: imageURL!)
} catch {}


// Use the URL to retrieve the image for sharing to email, social media, etc.
// docController.URL = imageURL
// ...

I force unwrapped some of the optionals for brevity. Use guard or if let in your code.