You should take advantage of the UIActivityItemSource
protocol. The activityItems
parameter of the initializer of UIActivityViewController
accepts either an array of data objects or an array of objects that implement the UIActivityItemSource
protocol.
As an example consider an item source like the following.
class MyStringItemSource: NSObject, UIActivityItemSource {
@objc func activityViewControllerPlaceholderItem(activityViewController: UIActivityViewController) -> AnyObject {
return ""
}
@objc func activityViewController(activityViewController: UIActivityViewController, itemForActivityType activityType: String) -> AnyObject? {
if activityType == UIActivityTypeMessage {
return "String for message"
} else if activityType == UIActivityTypeMail {
return "String for mail"
} else if activityType == UIActivityTypePostToTwitter {
return "String for twitter"
} else if activityType == UIActivityTypePostToFacebook {
return "String for facebook"
}
return nil
}
func activityViewController(activityViewController: UIActivityViewController, subjectForActivityType activityType: String?) -> String {
if activityType == UIActivityTypeMessage {
return "Subject for message"
} else if activityType == UIActivityTypeMail {
return "Subject for mail"
} else if activityType == UIActivityTypePostToTwitter {
return "Subject for twitter"
} else if activityType == UIActivityTypePostToFacebook {
return "Subject for facebook"
}
return ""
}
func activityViewController(activityViewController: UIActivityViewController, thumbnailImageForActivityType activityType: String!, suggestedSize size: CGSize) -> UIImage! {
if activityType == UIActivityTypeMessage {
return UIImage(named: "thumbnail-for-message")
} else if activityType == UIActivityTypeMail {
return UIImage(named: "thumbnail-for-mail")
} else if activityType == UIActivityTypePostToTwitter {
return UIImage(named: "thumbnail-for-twitter")
} else if activityType == UIActivityTypePostToFacebook {
return UIImage(named: "thumbnail-for-facebook")
}
return UIImage(named: "some-default-thumbnail")
}
}
The above item source returns different string data objects, subjects and thumbnail images based on the activity type. To use, you just need to pass it into the UIActivityViewController
initializer.
UIActivityViewController(activityItems: [MyStringItemSource()], applicationActivities: nil)
Similarly, you could define a custom MyUrlItemSource
class that returns different URLs based on the selected activity and pass it along in the initializer.
UIActivityViewController(activityItems: [MyStringItemSource(), MyUrlItemSource()], applicationActivities: nil)
All of this is outlined in the official documentation for UIActivityViewController
and UIActivityItemSource