Question

你好我们试图将Objective-c代码转换为swift我做了但我得到了错误这是我的代码

 func imageWithView(view: UIView) -> UIImage {
    UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.isOpaque, 0.0)
    view.drawHierarchy(in: view.bounds, afterScreenUpdates: true)
    let img = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return img!

}

@IBAction func uploadbutton(_ sender: Any)
{
    let viewcontroller = newViewController()

    viewcontroller.self.storyboard?.instantiateViewController(withIdentifier: "newViewController")
    viewcontroller.uiimageview = self.imageWithView(view: view1)
    self.present(viewcontroller, animated: true, completion: nil)


}

我在代码中遇到错误：无法将类型'UIImage'的值分配给UIImageView类型

viewcontroller.uiimageview = self.imageWithView(view: view1)

Answer 1

尝试viewcontroller.uiimageview.image = self.imageWithView(view: view1)

图像视图只是一个包含图像属性的视图容器

Answer 2

imageWithView(view:)的结果是UIImage，但您将其分配给UIImageView对象。

viewcontroller.uiimageview.image = self.imageWithView(view: view1)

Answer 3

我强烈建议您修改问题。听起来（从您的评论中）您希望：

选择UIView并创建UIImage
选择UIImage并在UIActivityViewController

你不需要做更多的事情！假设你已经有UIViewController显示（1）您要上传的视图，包括它的子视图，以及（2）有一个按钮来显示要分享的选项。以下是如何完成这两个：

这是一个扩展视图（及其子视图）并返回UIImage。

extension UIView {
    public func createImage() -> UIImage {
        UIGraphicsBeginImageContextWithOptions(
            CGSize(width: self.frame.width, height: self.frame.height), true, 1)
        self.layer.render(in: UIGraphicsGetCurrentContext()!)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image!
    }
}

现在你有一个UIImage，只需出示一个UIActivityViewController：

@IBAction func shareImage(_ sender: UIBarButtonItem) {
    var shareImage = myView.createUIImage()
    let vc = UIActivityViewController(activityItems: [shareImage], applicationActivities: [])
    vc.excludedActivityTypes =  [
        //UIActivityTypePostToTwitter,
        //UIActivityTypePostToFacebook,
        UIActivityType.postToWeibo,
        //UIActivityTypeMessage,
        //UIActivityTypeMail,
        UIActivityType.print,
        //UIActivityTypeCopyToPasteboard,
        UIActivityType.assignToContact,
        //UIActivityTypeSaveToCameraRoll,
        UIActivityType.addToReadingList,
        //UIActivityTypePostToFlickr,
        UIActivityType.postToVimeo,
        UIActivityType.postToTencentWeibo
    ]
    present(vc,
            animated: true,
            completion: nil)
    vc.popoverPresentationController?.sourceView = self.view
    vc.completionWithItemsHandler = {(activity, success, items,  error) in
    }
}

我通常会将所有排除在外的UIActivityTypes（甚至是我评论出来的那些）包含在内，以提醒我那些我所包含的内容。

将uiivew转换为图像

3 个答案: