C# 打印机连接状态判断

原文：https://www.cnblogs.com/Old-Fish/p/6258118.html

/// <summary>
        /// 判断是否连接打印机
        /// </summary>
        public bool CheckPrinter()
        {
            //取得默认打印机名
            PrintDocument pdoc = new PrintDocument();
            string printerName1 = pdoc.PrinterSettings.PrinterName;

            ManagementScope scope = new ManagementScope(@"\root\cimv2");
            scope.Connect();

            // Select Printers from WMI Object Collections
            ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_Printer");

            string printerName = "";
            foreach (ManagementObject printer in searcher.Get())
            {
                printerName = printer["Name"].ToString().ToLower();
                if (printerName.IndexOf(printerName1.ToLower()) > -)
                {

                    if (printer["WorkOffline"].ToString().ToLower().Equals("true"))
                    {
                        switch (MessageBox.Show("默认打印机未连接或出错", "警告", MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Error))
                        {
                            case DialogResult.Retry:
                                CheckPrinter();
                                break;
                        }
                        return false;
                        // printer is offline by user

                    }
                    else
                    {
                        // printer is not offline

                        return true;
                    }
                }
            }
            switch (MessageBox.Show("默认打印机未连接或出错", "警告", MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Error))
            {
                case DialogResult.Retry:
                    CheckPrinter();
                    break;
            }
            return false;
        }

        /// <summary>
        /// 判断打印机状态,传Exception
        /// </summary>
        /// <param name="ex">Exception</param>
        public void ErrerPrint(Exception ex)
        {
            PrintQueue pq = LocalPrintServer.GetDefaultPrintQueue();
            string PrintStaticText = "";
            bool isPrintErrer = false;

            switch (pq.QueueStatus)
            {
                case PrintQueueStatus.Busy:
                    PrintStaticText = "打印机正忙";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.DoorOpen:
                    PrintStaticText = "打印机上的门已打开";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.Error:
                    PrintStaticText = "由于错误情况，打印机无法打印。";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.IOActive:
                    PrintStaticText = "打印机正在与打印服务器交换数据";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.Initializing:
                    PrintStaticText = "打印机正在初始化";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.ManualFeed:
                    PrintStaticText = "打印机正在等待用户将打印介质放入手动送纸盒";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.NoToner:
                    PrintStaticText = "打印机墨粉用完";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.None:
                    PrintStaticText = "未指定状态。";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.NotAvailable:
                    PrintStaticText = "状态信息不可用";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.Offline:
                    PrintStaticText = "打印机处于脱机状态。";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.OutOfMemory:
                    PrintStaticText = "打印机无可用内存";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.OutputBinFull:
                    PrintStaticText = "打印机的输出纸盒已满";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.PagePunt:
                    PrintStaticText = "打印机不能打印当前页";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.PaperJam:
                    PrintStaticText = "打印机卡纸";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.PaperOut:
                    PrintStaticText = "打印机中没有或已用完当前打印作业所需的纸张类型";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.PaperProblem:
                    PrintStaticText = "打印机中的纸张导致未指定的错误情况";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.Paused:
                    PrintStaticText = "打印队列已暂停";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.PendingDeletion:
                    PrintStaticText = "打印队列正在删除打印作业";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.PowerSave:
                    PrintStaticText = "打印机处于节能模式";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.Printing:
                    PrintStaticText = "设备正在打印";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.Processing:
                    PrintStaticText = "设备正在执行某种工作，如果此设备是集打印机、传真机和扫描仪于一体的多功能设备，则不需要打印";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.ServerUnknown:
                    PrintStaticText = "打印机处于错误状态";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.TonerLow:
                    PrintStaticText = "打印机中只剩下少量墨粉";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.UserIntervention:
                    PrintStaticText = "打印机要求通过用户操作来更正错误情况";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.Waiting:
                    PrintStaticText = "打印机正在等待打印作业";
                    isPrintErrer = true;
                    break;
                case PrintQueueStatus.WarmingUp:
                    PrintStaticText = "打印机正在预热";
                    isPrintErrer = true;
                    break;
            }

            if (isPrintErrer)
            {
                WriteLog.SetString(PrintStaticText);
                MessageBox.Show(PrintStaticText, "警告", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            if (ex.Message == "The net printer is unavailable.")
            {
　　　　　　　　　　

                MessageBox.Show("网络打印机不可用", "警告", MessageBoxButtons.OK, MessageBoxIcon.Error);
                WriteLog.SetString(ex.Message);
            }
            else
            {
                WriteLog.SetException(ex);
            }
        }