Swift屏幕截图图像分辨率与UigraphicSgetImageFromCurrentImageContext有关

Question

我有一个长的日历屏幕滚动并尝试共享完整日历的完整屏幕截图，使用了此扩展名，但在iPhone 8加上真实设备上获得了202x1024的不良图像质量。我如何获得完整的分辨率屏幕截图，包括屏幕的滚动区域。

fileprivate extension UITableView {
    func screenshot() -> UIImage? {
        let savedContentOffset = contentOffset
        let savedFrame = frame
        UIGraphicsBeginImageContext(contentSize)
        contentOffset = .zero
        frame = CGRect(x: 0, y: 0, width: contentSize.width, height: contentSize.height)
        guard let context = UIGraphicsGetCurrentContext() else { return nil }
        layer.render(in: context)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        contentOffset = savedContentOffset
        frame = savedFrame
        return image
    }
}

Answer 1

您是否尝试过为图像上下文指定刻度？

UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.mainScreen().scale)