Basic example for sharing text or image with UIActivityViewController in Swift

I started my search by wanting to know how I could share to other apps in iOS. I discovered that two important ways are

UIActivityViewController
UIDocumentInteractionController

These and other methods are compared in this SO answer.

Often when I am learning a new concept I like to see a basic example to get me started. Once I get something basic set up I can modify it how I like later.

There are many SO questions related to UIActivityViewController, but I couldn't find any that were just asking for a simple example. Since I just learned how to do this, I will provide my own answer below. Feel free to add a better one (or an Objective-C version).

Solution

UIActivityViewController Example Project

Set up your storyboard with two buttons and hook them up to your view controller (see code below).

Add an image to your Assets.xcassets. I called mine "lion".

Code

import UIKit
class ViewController: UIViewController {
    
    // share text
    @IBAction func shareTextButton(_ sender: UIButton) {
        
        // text to share
        let text = "This is some text that I want to share."
        
        // set up activity view controller
        let textToShare = [ text ]
        let activityViewController = UIActivityViewController(activityItems: textToShare, applicationActivities: nil)
        activityViewController.popoverPresentationController?.sourceView = self.view // so that iPads won't crash
        
        // exclude some activity types from the list (optional)
        activityViewController.excludedActivityTypes = [ UIActivity.ActivityType.airDrop, UIActivity.ActivityType.postToFacebook ]
        
        // present the view controller
        self.present(activityViewController, animated: true, completion: nil)
        
    }
    
    // share image
    @IBAction func shareImageButton(_ sender: UIButton) {
        
        // image to share
        let image = UIImage(named: "Image")
        
        // set up activity view controller
        let imageToShare = [ image! ]
        let activityViewController = UIActivityViewController(activityItems: imageToShare, applicationActivities: nil)
        activityViewController.popoverPresentationController?.sourceView = self.view // so that iPads won't crash
        
        // exclude some activity types from the list (optional)
        activityViewController.excludedActivityTypes = [ UIActivity.ActivityType.airDrop, UIActivity.ActivityType.postToFacebook ]
        
        // present the view controller
        self.present(activityViewController, animated: true, completion: nil)
    }
    
}

Result

Clicking "Share some text" gives result on the left and clicking "Share an image" gives the result on the right.

Notes

I retested this with iOS 11 and Swift 4. I had to run it a couple times in the simulator before it worked because it was timing out. This may be because my computer is slow.
If you wish to hide some of these choices, you can do that with excludedActivityTypes as shown in the code above.
Not including the popoverPresentationController?.sourceView line will cause your app to crash when run on an iPad.
This does not allow you to share text or images to other apps. You probably want UIDocumentInteractionController for that.

Basic example for sharing text or image with UIActivityViewController in Swift

UIActivityViewController Example Project

Code

Result

Notes

See also