swift - 有没有办法获得 ping 的结果，显示在文本框中，但没有旋转的色轮？

Question

由于 ping 的结果可能需要超过 4 秒(取决于跳数)，我得到了旋转的色轮(沙滩球)，这通常表示程序已锁定或无法运行。

应用会继续旋转色轮，并在文本框中显示结果。有没有办法摆脱“沙滩球”？

我通过将结果打印到每个变量来进行调试。 在执行“let handle1 = pipe.fileHandleForReading”后，沙滩球出现了。 我尝试了 Grand Central Dispatch (GCD)，但仍然得到相同的结果。

// Built using X-Code Version 8.2.1 - Swift Version 3.0.2

// Text view for results (display)
@IBOutlet weak var Results: NSTextField!

// Start button to execute ping
@IBAction func startButton(_ sender: Any)
{
    cmdPing()
}

// Global variables
var myArg = ""
var shellResults = ""

func cmdPing()
{
    // Step 1
    myArg = "ping -c 10 www.google.com"
    shellResults = getPing(shellArgs: myArg)
    Results.stringValue = shellResults

    // Step 2
    myArg = "ping -c 10 127.0.0.1"
    shellResults = getPing(shellArgs: myArg)
    Results.stringValue = shellResults

}


// function that executes a shell command and returns its value (myArg)
func getPing(shellArgs: String) -> String
{
    let task:Process = Process()
    let pipe:Pipe = Pipe()
    task.launchPath = "/bin/sh"
    task.arguments = ["-c", shellArgs]
    task.standardOutput = pipe
    task.launch()
    let handle1 = pipe.fileHandleForReading
    let data1 = handle1.readDataToEndOfFile()
    let result1 = NSString(data: data1, encoding: String.Encoding.utf8.rawValue)
    let trimmed1 = (result1! as NSString).trimmingCharacters(in: NSCharacterSet.whitespaces)
    shellResults = trimmed1
    task.waitUntilExit()
    return shellResults
}

我确实在文本框中得到了结果。如果可以做到的话，最好是在没有“沙滩球”的情况下，在每次 ping 期间在文本框中显示每一行(跃点)。任何帮助将不胜感激。

Answer 1

这才是有效的。它将执行命令并返回 TextView 或 ScrollView 窗口中的每个跃点。这将摆脱旋转的“沙滩球”。添加了一个计数器或者你可以做一个循环来继续你的许多任务(命令 ping)

func getPing(shellArgs: String)
{

    let task = Process()
    task.launchPath = "/bin/sh"
    task.arguments = ["-c", shellArgs]

    let pipe = Pipe()
    task.standardOutput = pipe
    let outHandle = pipe.fileHandleForReading
    outHandle.waitForDataInBackgroundAndNotify()

    var obs1 : NSObjectProtocol!
    obs1 = NotificationCenter.default.addObserver(forName: NSNotification.Name.NSFileHandleDataAvailable, object: outHandle, queue: nil)
    {
        notification -> Void in let data = outHandle.availableData

        if data.count > 0
        {
            if let str = NSString(data: data, encoding: String.Encoding.utf8.rawValue)
            {
                // place data (str) in Results (textview) window
                self.Results.stringValue += "\(str)"
            }
            outHandle.waitForDataInBackgroundAndNotify()
        }
        else
        {
            print("EOF on stdout from process")
            NotificationCenter.default.removeObserver(obs1)
        }
    }

    var obs2 : NSObjectProtocol!
    obs2 = NotificationCenter.default.addObserver(forName: Process.didTerminateNotification, object: task, queue: nil)
    {
        notification -> Void in print("terminated")
        NotificationCenter.default.removeObserver(obs2)
        if self.pingCount < 3
        {
            // add counter and continue for other commands (steps)
            self.pingCount += 1
            self.cmdPing()
        }
        else
        {
            // end task
            task.terminate()
        }
    }
    task.launch()
}