ios - 屏幕上未显示的 VC 的屏幕截图

Question

我需要截取属于另一个不在屏幕上的 View Controller 的一部分的 View 的屏幕截图。

我相信我需要创建该 VC，用正确的数据填充它，“渲染它”，然后截取屏幕截图，我该怎么做？

这是我当前的代码，它从目标 VC 触发 viewDidLoad() 但生成空白图像:

    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = storyboard.instantiateViewController(withIdentifier: "ShareVC") as! ShareTransactionViewController
    vc.transaction = self.transaction

    vc.view.drawHierarchy(in: self.view.bounds, afterScreenUpdates: false)

    UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, true, 0.0)

    let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()

    let imageToShare = [ image ]

提前谢谢

Answer 1

经过一番工作后，我设法找到了一个解决方案，它可能不是最好的解决方案，因此如果有人有更好的方法，我将不胜感激。

我在当前 View Controller 中添加了一个 View ，以便我可以将目标 View 添加到其中。我捕获图像，然后删除添加的 View ，以便当前 VC 看起来与原来相同。

func share(sender:UIBarButtonItem){

    // Create the VC that has the view we are going to share
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = storyboard.instantiateViewController(withIdentifier: "ShareVC") as! ShareTransactionViewController
    vc.transaction = self.transaction

    // Prepare the image context
    UIGraphicsBeginImageContextWithOptions(self.snap.bounds.size, true, 0.0)

    // Draw the view we want to share from the created VC into the current VC
    vc.view.drawHierarchy(in: self.snap.bounds, afterScreenUpdates: true)

    // Adds the view from the other vc to the snap of the current VC
    self.snap.insertSubview(vc.view, at:0)

    // Redraws all the views of this vc
    self.view.drawHierarchy(in: self.view.bounds, afterScreenUpdates: true)

    // Defining the variable for activityItems
    let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()

    let imageToShare = [ image ]
    let activityViewController = UIActivityViewController(activityItems: imageToShare, applicationActivities: nil)

    // set up activity view controller
    activityViewController.popoverPresentationController?.sourceView = self.view  // so iPads won't crash

    // Present the view controllet that shares the content
    self.present(activityViewController, animated: true, completion: nil)

    // Removes added subview in current VC
    for view in self.snap.subviews {
        view.removeFromSuperview()
    }

}