Swift:截取 viewController 的屏幕截图，并在 Facebook 上分享

Question

我创建了以下函数来在Facebook上分享帖子：

@IBAction func socialShare(_ sender: Any){
    //Alert
    let alert = UIAlertController(title: "Share", message: "First share!", preferredStyle: .actionSheet)
    //First action
    let actionOne = UIAlertAction(title: "Share on Facebook", style: .default) { (action) in
        //Checking if user is connected to Facebook
        if SLComposeViewController.isAvailable(forServiceType: SLServiceTypeFacebook)
        {
            let post = SLComposeViewController(forServiceType: SLServiceTypeFacebook)!
            post.setInitialText("First")
            post.add(UIImage(named: "Mylogo.png"))
            self.present(post, animated: true, completion: nil)
        } else {self.showAlert(service: "Facebook")}
    }
    let actionThree = UIAlertAction(title: "Cancel", style: .cancel, handler: nil)
    //Add action to action sheet
    alert.addAction(actionOne)
    alert.addAction(actionThree)
    //Present alert
    self.present(alert, animated: true, completion: nil)    
}
func showAlert(service:String){
    let alert = UIAlertController(title: "Error", message: "You are not connected to (service)", preferredStyle: .alert)
    let action = UIAlertAction(title: "Dismiss", style: .cancel, handler: nil)
    alert.addAction(action)
    present(alert, animated: true, completion: nil)
}

但我真正想做的是共享一个图像，这个图像必须是用户点击共享按钮的视图控制器的屏幕截图。这可能吗？如果是这样，如何？

更新：

对于屏幕截图，我找到了这样的函数：

func screenShotMethod() {
    //Create the UIImage
    UIGraphicsBeginImageContext(view.frame.size)
    view.layer.renderInContext(UIGraphicsGetCurrentContext())
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    //Save it to the camera roll
    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
}

但是我不知道如何在我的代码中实现它。

Answer 1

要做到这一点，你可以做这样的事情

func screenShotMethod() -> UIImage? {
    //Create the UIImage
    UIGraphicsBeginImageContext(view.frame.size)
    view.layer.render(in: UIGraphicsGetCurrentContext()!)
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return image
}

并将其添加到：

    let post = SLComposeViewController(forServiceType: SLServiceTypeFacebook)!
    post.setInitialText("First")
    post.add(screenShotMethod())
    self.present(post, animated: true, completion: nil)