nsprintoperation检查用户选择了什么

Question

使用此代码，我可以打印一个pdf文件：

let dictDocuments = NSURL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0])
let completePath = dictDocuments.appendingPathComponent("test.pdf")
let pdfDocument = PDFDocument(url: completePath!)

let printInfoDict = NSMutableDictionary(dictionary: NSPrintInfo.shared().dictionary())
printInfoDict.setObject(NSPrintSpoolJob, forKey: NSPrintJobDisposition as NSCopying)
let printInfo = NSPrintInfo(dictionary: printInfoDict as! [String : Any])
printInfo.isHorizontallyCentered = true
printInfo.isVerticallyCentered = true
printInfo.scalingFactor = 1.5


let printOp = pdfDocument!.printOperation(for: printInfo, scalingMode: .pageScaleNone, autoRotate: true)!
printOp.runModal(for: self.view.window!, delegate: self, didRun: nil, contextInfo: nil)

我可以检查一下，用户在打印面板中选择了哪个按钮？(取消或打印)

Answer 1

来自文档

didRunSelector参数指定的方法必须具有以下签名： func printOperationDidRun(_ printOperation NSPrintOperation，success: Bool，contextInfo: UnsafeMutableRawPointer?) 如果打印操作在没有取消或错误的情况下运行到完成，则成功的值为true，否则为false。 如果将canSpawnSeparateThread发送到带有true参数的NSPrintOperation对象，则在随后调用runOperationModalForWindow:delegate:didRunSelector:contextInfo:时指定的委托可能会在该生成的非主线程中传递消息。

Answer 2

如欲迅速5.1：

// prepare printOp
...

{
        //was: printOp.run()

        if let w = NSApp.mainWindow{
            let selector = #selector(printOperationDidRun(printOperation: success: contextInfo:))
            printOp.runModal(for: w, delegate: self,
                             didRun: selector,
                             contextInfo: nil)
        }
    }

    // apple docs:
    // - (void)printOperationDidRun:(NSPrintOperation *)printOperation  success:(BOOL)success  contextInfo:(void *)contextInfo

     @objc func printOperationDidRun( printOperation: NSPrintOperation,
                                      success: Bool,
                                      contextInfo: UnsafeMutableRawPointer?){
        // use callback..

    }