ios - 以编程方式在 swift 上截图

Question

当我快速按下一个按钮时，我正在尝试截取整个 View 。问题是，当我截屏时，有些部分被切断了，比如顶部...

被截断的其他部分是我在屏幕底部的容器 View 。它包含一个开关、一个文本字段和一个按钮。这是我用来截屏的代码......

func screenShotMethod() {
    let layer = UIApplication.shared.keyWindow!.layer
    let scale = UIScreen.main.scale
    UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale);

    layer.render(in: UIGraphicsGetCurrentContext()!)
    let screenshot = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    UIImageWriteToSavedPhotosAlbum(screenshot!, nil, nil, nil)
}

这是我用来创建容器 View 的代码...

lazy var inputContainerView: UIView = {

    let containerView = UIView()
    containerView.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: 50)
    containerView.backgroundColor = UIColor.white
    //Other things...

override var inputAccessoryView: UIView? {
    get {
        return inputContainerView
    }
}

override var canBecomeFirstResponder : Bool {
    return true
}

这就是结局图像的样子......

那我该怎么做才能解决呢？谢谢!

Answer 1

如果您具有某种 Objective-C 知识，那么这里就是您想要的答案。

打开这个Link并遵循遍历所有 View 层次结构的最后一个答案，并逐行注释以完全理解代码。

图像最终被转换为NSData 和UIImage。如果你仍然感到困惑，那么我可以将它转换成 swift，但首先你自己尝试一下。

这是该答案的 Swift 代码。

func screenshot() -> UIImage {
    let imageSize = UIScreen.main.bounds.size as CGSize;
    UIGraphicsBeginImageContextWithOptions(imageSize, false, 0)
    let context = UIGraphicsGetCurrentContext()
    for obj : AnyObject in UIApplication.shared.windows {
        if let window = obj as? UIWindow {
            if window.responds(to: #selector(getter: UIWindow.screen)) || window.screen == UIScreen.main {
                                // so we must first apply the layer's geometry to the graphics context
                                context!.saveGState();
                                // Center the context around the window's anchor point
                                context!.translateBy(x: window.center.x, y: window.center
                                    .y);
                                // Apply the window's transform about the anchor point
                                context!.concatenate(window.transform);
                                // Offset by the portion of the bounds left of and above the anchor point
                context!.translateBy(x: -window.bounds.size.width * window.layer.anchorPoint.x,
                                     y: -window.bounds.size.height * window.layer.anchorPoint.y);

                                // Render the layer hierarchy to the current context
                                window.layer.render(in: context!)

                                // Restore the context
                                context!.restoreGState();
            }
        }
    }
    let image = UIGraphicsGetImageFromCurrentImageContext();
    return image!
}