Xamarin Zebra Sdk - 蓝牙打印“读取失败，插座可能关闭或超时，读取ret：-1”

Posted 2021-03-31

我正在使用最新的Xamarin Zebra SDK打印到ZQ520打印机。大约70％的时间打印工作正常。其余30％的时间因错误而失败

“读取失败，套接字可能关闭或超时，读取ret：-1”

并且需要关闭/打开打印机才能进行打印。

我发送的内容是签名和标签，我在不安全的蓝牙连接上打印。

事实证明难以一致地重现错误。我想它可能与我的代码中的initialResponseTimeout和responseCompletionTimeout有关。有没有人设置这些值的经验？

        IConnection connection = null;

        try
        {

            connection = new BluetoothConnectionInsecure(address);
            connection.Open();

            using (var printer = ZebraPrinterFactory.GetInstance(
                               PrinterLanguage.Cpcl, connection))
            {

                using (var image = ZebraImageFactory.GetImage(signature))
                {
                   printer.StoreImage(SignatureFilename, image,
                              image.Width, image.Height);
                }

                // pause to ensure image is saved
                Thread.Sleep(1000);

                var initialResponseTimeout = 3000;
                var responseCompletionTimeout = 1000;

                // is the timeout too small or large ?
                connection.SendAndWaitForResponse(printLabel,
                initialResponseTimeout, responseCompletionTimeout, null);
            }

        }

        catch (Exception exception)
        {
            Microsoft.AppCenter.Crashes.Crashes.TrackError(exception);
        }
        finally
        {
            connection.Close();
        } 

答案

当我尝试直接连接我的设备时，我遇到了相关问题。我建议您在本地计算机上创建一个应用程序，以便与您的手机和打印机进行通信。还尝试增加代码中的超时。

 using (var printer = ZebraPrinterFactory.GetInstance(
                           PrinterLanguage.Cpcl, connection))
        {

            using (var image = ZebraImageFactory.GetImage(signature))
            {
               printer.StoreImage(SignatureFilename, image,
                          image.Width, image.Height);
            }

            // pause to ensure image is saved
            //Thread.Sleep(1000); I recommend you to remove this line

            var initialResponseTimeout = 15000;
            var responseCompletionTimeout = 15000;

            // is the timeout too small or large ?
            connection.SendAndWaitForResponse(printLabel,
            initialResponseTimeout, responseCompletionTimeout, null);
        }