如何在 Swift 3 中为 UIPrintInfo 打印缩放到页面的 UIImage？答案

【问题标题】：How to print an UIImage with scale to page for UIPrintInfo in Swift 3?如何在 Swift 3 中为 UIPrintInfo 打印缩放到页面的 UIImage？
【发布时间】：2018-04-24 21:45:55
【问题描述】：

我有一个带有子视图的 UIView，如下图所示。

在这里我必须打印或分享标记的 - 视图。

为了分享，我将标记的 UIView 转换为 PDF 并在电子邮件中分享。效果完全符合我的客户的预期。

为了打印，我将标记的 UIView 转换为 UIImage 并打印出来。它也可以工作，但我除了必须打印转换后的 UIImage 并缩放到页面。 但收据打印太小，如下图（Epson TM-T88V 打印机）。

我将 UIView 转换为 UIImage 的代码：

extension UIView {
    func toImage() -> UIImage {
        UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.main.scale)
        drawHierarchy(in: self.bounds, afterScreenUpdates: false)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image!
    }
}

我打印图片的代码：

@IBAction func act_PrintBtnPressed(_ sender: UIButton) {
    m_PrintView.frame.size.height = view.frame.size.height
    let printInfo = UIPrintInfo(dictionary:nil)
    printInfo.outputType = UIPrintInfoOutputType.photo
    printInfo.jobName = "PrintingReceipt"
    printInfo.orientation = .portrait

    let printController = UIPrintInteractionController.shared
    printController.printInfo = printInfo
    printController.printingItem = m_PrintView.toImage()
    printController.showsNumberOfCopies = false
    printController.present(animated: true, completionHandler: nil)
}

最后，如何设置份数必须在代码中打印。因为不想在UI中设置份数，所以我将printController.showsNumberOfCopies设置为false。

请指导我创建这个。

【问题讨论】：

标签： ios swift uiprintinteractioncntrler uiprintformatter

【解决方案1】：

最后我自己找到了。我通过 htmlString 创建了 uicontrols 值。并使用了如下所述的 UIPrintPageRenderer。

class TicketPrintPageRenderer: UIPrintPageRenderer {
    let receipt: String

    init(receipt: String) {
        self.receipt = receipt
        super.init()

        self.headerHeight = 0.0
        self.footerHeight = 0.0 // default

        let formatter = UIMarkupTextPrintFormatter(markupText: receipt)
        formatter.perPageContentInsets = UIEdgeInsets(top: 2, left: 2,
                                                      bottom: 2, right: 2)
        addPrintFormatter(formatter, startingAtPageAt: 0)
    }
}

这里正在为 html 字符串创建控件值，如下所述：

func createHTMLString(ticketDetail: Ticket, QRImage: UIImage) {
        let priceStr = String(format: "$%.02f", ticketDetail.price!)

        let storeLogoImage: String = self.getImage(imageName: "storeLogo")
        let qrCodeImagePath: String = self.getImage(imageName: "qrCode")
        printHtmlString = "<html lang=\"en\"><head><meta charset=\"UTF-8\"><meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\"><meta http-equiv=\"X-UA-Compatible\" content=\"ie=edge\"><title>Document</title><style>body {font-family: sans-serif;}.top_Content {text-align: center;padding-top: 10px;}.margin_8 {margin: 8px auto;}.fontstyle_normal {font-weight: normal;}.float_left {float: left;}.float_right {float: right;}.vl {border-left: 2px solid rgb(0, 0, 0);height: 40px;position: absolute;left: 50%;}.container_body{text-align: center;font-weight: normal;}.squareBackground {background-color: rgb(162, 161, 159);width: 100px;height: 100px;}</style></head><body><div><div class=\"top_Content\"><img src=\"file://\(storeLogoImage)\" alt=\"laundryboss_logo\" height=\"100px\"><h3 class=\"margin_8 fontstyle_normal\">\(EmployeeModel.sharedInstance.currentEmployee.employeeSelectedLocation.customerName!)</h3><h4 class=\"margin_8 fontstyle_normal\">\(EmployeeModel.sharedInstance.currentEmployee.employeeSelectedLocation.locationName!)</h4><h3 style=\"width:40%; padding-left: 17px; font-size:1em;\" class=\"float_left margin_8 fontstyle_normal\">Date : \((self.printShareViewModel?.splitDateandTime(createdAt: ticketDetail.ticketDate).createdDate)!)</h3><!-- <span>&#10072</span> --><div class=\"vl\"></div><h3 style=\"width:40%; padding-right: 17px; font-size:1em;\" class=\"float_right margin_8 fontstyle_normal\">Time : \((self.printShareViewModel?.splitDateandTime(createdAt: ticketDetail.ticketDate).createdTime)!)</h3><h2 style=\"margin: 0;clear: both;padding-top: 14px; font-size:1.2em;\" class=\"fontstyle_normal\">Ticket #\(ticketDetail.ticketNumber!)</h2><h2 style=\"margin: 0;clear: both;padding-top: 14px; font-size:1.2em;\" class=\"fontstyle_normal\">\(ticketDetail.user.name!)</h2><div style=\"display: table;margin: 0 auto;padding-top: 16px;\"><h2 style=\"margin: 0; font-size:1.2em;\" class=\"float_left fontstyle_normal\">Phone :</h2><h3 style=\"margin: 0; font-size:1.2em; padding-left:6px;\" class=\"float_left fontstyle_normal\">\(ticketDetail.user.phone!)</h3></div><p style=\"margin: 0;padding-top: 16px; font-size:1.2em;\">\(ticketDetail.notes!)</p><div style=\"display: table;margin: 0 auto;padding-top: 16px;\"><h2 style=\"margin: 0; font-size:1.2em;\" class=\"float_left fontstyle_normal\">Price :</h2><h3 style=\"margin: 0; font-size:1.2em; padding-left:6px;\" class=\"float_left fontstyle_normal\">\(priceStr)</h3></div><div style=\"margin: 0 auto;display: table; margin-top: 16px;\" class=\"squareBackground\"><!-- <div class=\"squareBackground\"> --><img src=\"file://\(qrCodeImagePath)\" alt=\"Qr_code\" width=\"90\" height=\"90\" align=\"middle\" style=\"padding:5px;\"><!-- </div> --></div></div></div></body></html>"
    }

现在当用户点击打印按钮时：

@IBAction func act_PrintBtnPressed(_ sender: UIButton) {   
        let formatter = TicketPrintPageRenderer(receipt: printHtmlString)
        let printController = UIPrintInteractionController.shared
        printController.showsNumberOfCopies = true
        printController.showsPageRange = false
        printController.printPageRenderer = formatter
        printController.present(animated: true) { (controller, success, errorMsg) in
            if success {
                print("*************** Print Successfully")
            } else {
                print("*************** Print Failed : \(errorMsg?.localizedDescription)")
            }
        }
    }

它符合我的例外情况。

【讨论】：