Question

我正在编写一个使用Pos for .Net的应用程序，并且我注意到如果你调用WaitForDrawerClose，那么你将无法打印收据直到它返回。

这不是理想的行为。还有另一种方法可以在不阻塞打印机的情况下等待现金抽屉关闭吗？

我已查看OnDrawerStateChanged Event，但这是CashDrawerBase的受保护成员，我并不完全确定如何访问它。

这是我的SSCCE：

static void Main(string[] args)
{
    var posExplorer = new PosExplorer();
    var waitTask = WaitForCloseAsync(posExplorer);
    System.Threading.Thread.Sleep(500);
    PrintText(posExplorer);
    waitTask.Wait();
}

public static Task WaitForCloseAsync(PosExplorer posExplorer)
{
    var result = Task.Factory.StartNew(() =>
    {
        Console.WriteLine("waiting");
        var cashDrawer = GetCashDrawer(posExplorer);
        cashDrawer.Open();
        cashDrawer.Claim(1000);
        cashDrawer.DeviceEnabled = true;
        cashDrawer.WaitForDrawerClose(10000, 4000, 500, 5000);
        cashDrawer.Release();
        cashDrawer.Close();
        Console.WriteLine("waited");
    });
    return result;
}

public static void PrintText(PosExplorer posExplorer)
{
    Console.WriteLine("printing");
    var printer = GetPosPrinter(posExplorer);
    printer.Open();
    printer.Claim(1000);
    printer.DeviceEnabled = true;
    var text = "abc\x1B|1lF";
    printer.PrintNormal(PrinterStation.Receipt, text);
    printer.Release();
    printer.Close();
    Console.WriteLine("printed");
}

public static CashDrawer GetCashDrawer(PosExplorer posExplorer)
{
    var deviceInfo = posExplorer.GetDevices(DeviceCompatibilities.Opos)
        .Cast<DeviceInfo>()
        .Where(d => d.Type == "CashDrawer")
        .ToList();

    var device = deviceInfo.FirstOrDefault(d => d.Compatibility == DeviceCompatibilities.Opos);

    if (device == null)
    {
        return null;
    }
    else
        return (CashDrawer)posExplorer.CreateInstance(device);
}

private static PosPrinter GetPosPrinter(PosExplorer posExplorer)
{
    var deviceInfo = posExplorer.GetDevices(DeviceCompatibilities.Opos)
        .Cast<DeviceInfo>()
        .Where(d => d.Type == "PosPrinter")
        .ToList();

    var device = deviceInfo.FirstOrDefault(d => d.Compatibility == DeviceCompatibilities.Opos);

    if (device == null)
    {
        return null;
    }
    else
    {
        return (PosPrinter)posExplorer.CreateInstance(device);
    }
}

Answer 1

所以，我所做的基本上是这样的：我不是使用（WaitForClose），而是像这样轮询它：

        for (var i = 0; i < 15; i++)
        {
            cashDrawer = GetCashDrawer(posExplorer);
            cashDrawer.Open();
            cashDrawer.Claim(1000);
            cashDrawer.DeviceEnabled = true;
            if (!cashDrawer.DrawerOpened)
            {
                Console.WriteLine("waited");
                return;
            }                    
            cashDrawer.Release();
            cashDrawer.Close();
            System.Threading.Thread.Sleep(1500);
        }
        Console.WriteLine("timed out");

它并不理想，但它也没有锁定打印机，所以它现在必须这样做。

WaitForDrawerClose阻止打印

1 个答案: