如何使用扩展市场保存裁剪的uiview屏幕截图

Question

我的扩展方法现在获取视图控制器内部的整个uiview的屏幕截图。我想用同样的函数来做同样的事情，只取uiview的一个确切区域，而不是整个视图。具体地说，我想捕获x:0，y:0，长度200，高度200，

    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!
    }

Answer 1

这样如何：

extension UIView {
    func screenshot(for rect: CGRect) -> UIImage {
        return UIGraphicsImageRenderer(bounds: rect).image { _ in
            drawHierarchy(in: CGRect(origin: .zero, size: bounds.size), afterScreenUpdates: true)
        }
    }
}

这使得它更具可重用性，但如果您愿意，您可以将其更改为硬编码值。

let image = self.view.screenshot(for: CGRect(x: 0, y: 0, width: 200, height: 200))