我的打印按钮如何打印8.5英寸x 11英寸的图像？Swift 3，IOS

if UIPrintInteractionController.canPrint(<#yourImage#>) {
    let printInfo = UIPrintInfo.printInfo()
    printInfo.outputType = .photo
    printInfo.jobName = "My Print Job"
    printInfo.orientation = .portrait
    printInfo.paperSize = CGSize(width: 8.5 * 72.0, height: 11.0 * 72.0) // 设置纸张尺寸，72.0是每英寸的点数

    let printController = UIPrintInteractionController.shared
    printController.printInfo = printInfo
    printController.printingItem = <#yourImage#> // 设置要打印的图像数据

    printController.present(animated: true, completionHandler: nil)
}