iOS Airprint 不使用打印机选择界面

Question

我正在制作一个应用程序，用户首先选择默认打印机，然后在单击“打印”按钮时继续，照片会自动打印，无需任何对话框。下面是我的代码。我收到错误消息“PrintViewController 没有初始化程序”

class PrintViewController: UIViewController {

var defaultPrinter : UIPrinter

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}


func SelecteDefaultPrinter(){
    let printerPicker = UIPrinterPickerController(initiallySelectedPrinter: nil)
    printerPicker.present(from: CGRect(x: 0, y: 0, width: 600, height: 500), in: self.view, animated: true) { (printerPicker, userDidSelect, error) in
        if userDidSelect {
            //Here get the selected UIPrinter
            self.defaultPrinter = printerPicker.selectedPrinter!
        }
    }
}


@IBAction func Button_DefaultPrinter(_ sender: Any) {
    SelecteDefaultPrinter()
}

//In your view controller
@IBAction func printButton(sender: AnyObject) {

    let printInfo = UIPrintInfo(dictionary:nil)
    printInfo.outputType = UIPrintInfoOutputType.general
    printInfo.jobName = "Test Print"

    // Set up print controller
    let printController = UIPrintInteractionController.shared
    printController.printInfo = printInfo

    // Assign a UIImage version of my UIView as a printing iten
    printController.printingItem = self.view.toImage()

    // Assign a Specific Image to printing item
    //printController.printingItem = customImageView.image

    // Print With Dialogue Box
    //printController.present(from: self.view.frame, in: self.view, animated: true, completionHandler: nil)


    // Print Without Dialogue Box
    printController.print(to: defaultPrinter, completionHandler: {(controller, success, error) -> Void in
        if success {
            debugPrint("Printing Completed.")
        } else {
            debugPrint("Printing Failed.")
        }
    })
}

Answer 1

解决了!这是错误的

var defaultPrinter : UIPrinter!

它正在吞噬我的大脑。 :D