Question

我在使用带有BT_MULTI连接类型的Zebra SDK中使用ConnectionBuilder类时遇到问题。 Zebra代表告诉我，这是一个已知的错误，他们没有修复ETA。

我用来连接打印机的代码如下：

    if (isBluetoothAvailable()) {
        // Make sure we still aren't connected to a printer
        if (thePrinterConnection != null &&
                thePrinterConnection.isConnected()) {
            thePrinterConnection.close();
        }

        // Connect to the printer
        Log.wtf(TAG, "Creating printer connection");

        /* TODO: This should be how the printer is connected to check status when printing,
         * TODO:  but currently throws ConnectionException with "Invalid connection type".
          */
        //thePrinterConnection = ConnectionBuilder.build("BT_MULTI:" + macAddress);
        thePrinterConnection = ConnectionBuilder.build("BT:" + macAddress);

        // Open the connection
        Log.wtf(TAG, "Opening connection");
        thePrinterConnection.open();

        // Get instance of link os printer
        thePrinterInstance = ZebraPrinterFactory.getLinkOsPrinter(thePrinterConnection);

        return true;
    } else {
        return false;
    }

注释掉的行是当前使用BT_MULTI标记的失败调用。

每次打印时，我都使用Connection类中的异步write（）方法。要检查打印机是否已准备好进行下一次打印，请通过执行以下方法确保打印机已准备就绪：

public boolean isPrinterReady() {
    /**
     * FIXME: If the printer is receiving data while this is called,
     * FIXME: it throws an exception, even if not printing. Above code might work with blocked
     * FIXME: channel, but currently will not connect to printer.
     */

    // Make sure we have a connection
    if (thePrinterConnection != null && thePrinterInstance != null) {
        try {
            // Try to get current printer status
            Log.wtf(TAG, "Printer is ready: " + thePrinterInstance.getCurrentStatus().isReadyToPrint);
            return thePrinterInstance.getCurrentStatus().isReadyToPrint;
        } catch (ConnectionException e) {
            Log.wtf(TAG, "Error getting printer status", e);
            return false;
        }
    } else {
        Log.wtf(TAG, "Printer connection was null");
        return false;
    }
}

如上面的评论中所述，当打印机处于write（）调用的中间并且我调用getCurrentStatus（）方法时，它会锁定打印机。之后，它将不会返回状态（抛出格式错误的状态异常）并且不会继续打印。打印机需要重新启动才能再次运行。

有人有任何替代方案的建议吗？

谢谢！

Zebra Link-OS Android SDK多渠道连接

0 个答案: