ios - 截图在模拟器中有效，但在真实设备上失败

Question

我有以下代码截取游戏屏幕截图，然后在点击“分享”按钮时分享它。

它在模拟器上运行良好并返回正确的图像。但是，在我的真实设备上，它返回一个白色图像。每次。

代码如下:

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

    let Touch : UITouch! = touches.first
    let TouchLocation = Touch.location(in: self)

    if let body = self.physicsWorld.body(at: TouchLocation){

        if body.node!.name == "shareButton" {
                let postText: String = "Check out my score! Can you beat it?"
                let postImage: UIImage = getScreenshot()
                let activityItems = [postText as AnyObject, postImage] //as [Any]
                let activityController = UIActivityViewController(
                    activityItems: activityItems,
                    applicationActivities: nil
                )

                let controller: UIViewController = scene!.view!.window!.rootViewController!

                controller.present(
                    activityController,
                    animated: true,
                    completion: nil
                )
        }
    }
}

函数如下:

func getScreenshot() -> UIImage {
    let snapshotView = self.view!.snapshotView(afterScreenUpdates: true)
    let bounds = UIScreen.main.bounds

    UIGraphicsBeginImageContextWithOptions(bounds.size, false, 0)

    snapshotView?.drawHierarchy(in: bounds, afterScreenUpdates: true)

    let screenshotImage : UIImage = UIGraphicsGetImageFromCurrentImageContext()!

    UIGraphicsEndImageContext()

    return screenshotImage;
}

我将我的问题缩小到这些代码行:

let postText: String = "Check out my score! Can you beat it?"
let postImage: UIImage = getScreenshot()
let activityItems = [postText as AnyObject, postImage] //as [Any]
let activityController = UIActivityViewController(
    activityItems: activityItems,
    applicationActivities: nil
)

let controller: UIViewController = scene!.view!.window!.rootViewController!

controller.present(
    activityController,
    animated: true,
    completion: nil
)

func getScreenshot() -> UIImage {
    let snapshotView = self.view!.snapshotView(afterScreenUpdates: true)
    let bounds = UIScreen.main.bounds

    UIGraphicsBeginImageContextWithOptions(bounds.size, false, 0)

    snapshotView?.drawHierarchy(in: bounds, afterScreenUpdates: true)

    let screenshotImage : UIImage = UIGraphicsGetImageFromCurrentImageContext()!

    UIGraphicsEndImageContext()

    return screenshotImage;
}

请注意，我只使用一个类。这个:

class GameScene: SKScene {
}

我通过创建一个新应用缩小了范围。除了添加这些代码行之外，我对默认的 Hello World 应用程序没有任何更改。它们返回相同的结果:空白图像。

感谢所有帮助!

Answer 1

这是我用来截图的代码。最大的不同是我有 false，而你有 true 的 afterScreenUpdates:

public extension UIView {
    public func snapshotImage() -> UIImage? {
        UIGraphicsBeginImageContextWithOptions(bounds.size, isOpaque, 0)
        drawHierarchy(in: bounds, afterScreenUpdates: false)
        let snapshotImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return snapshotImage
    }

    public func snapshotView() -> UIView? {
        if let snapshotImage = snapshotImage() {
            return UIImageView(image: snapshotImage)
        } else {
            return nil
        }
    }
}