Swift实现截屏并保存相册

 func saveToLocal() {
        //截屏
        let screenRect = UIScreen.mainScreen().bounds
        UIGraphicsBeginImageContext(screenRect.size)
        let ctx:CGContextRef = UIGraphicsGetCurrentContext()!
        self.view.layer.renderInContext(ctx)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext();

        //保存相册
        UIImageWriteToSavedPhotosAlbum(image!, self, "image:didFinishSavingWithError:contextInfo:", nil)

    }

    func image(image:UIImage,didFinishSavingWithError error:NSError?,contextInfo:AnyObject) {

        if error != nil {
            K12ProgressHUD.showError("保存失败", view: self.view)
        } else {
            K12ProgressHUD.showSucess("保存成功", view: self.view)
        }
    }