CODEWITHSUNDEEP
c#posprinter
Tamer Hatoum
Tamer Hatoum

Reputation: 49

PosPrinter for .net Printing only once and Hangs

I am building winforms .net Application , I have a E-Pos printer on Network , using this Code below : On Form Loading Printer initializing : 

    explorer = new PosExplorer(this);
        DeviceInfo receiptPrinterDevice = explorer.GetDevice("PosPrinter", Properties.Settings.Default.KitchenPrinter); //May need to change this if you don't use a logicial name or use a different one.
        kitchenPrinter = (PosPrinter)explorer.CreateInstance(receiptPrinterDevice);
       ConnectToPrinter();


    private void ConnectToPrinter()
    {  
        kitchenPrinter.Open();
        kitchenPrinter.Claim(10000);
        kitchenPrinter.DeviceEnabled = true;
     }

Function Call on Print Button : 

 private void PrintReceipt()
    {

         try
            {  kitchenPrinter.PrintNormal(PrinterStation.Receipt, "test");
              }
            finally
            {

            }
    }

When I want to Switch to Other Form I call Disconnect Function 

        DisconnectFromPrinter(kitchenPrinter);
        Reporting frm = new Reporting(curuser);
        frm.Show();
        this.Hide();


  private void DisconnectFromPrinter(PosPrinter kitchenPrinter)
    {

        try
        {
           kitchenPrinter.Release();
            kitchenPrinter.Close();
        }
       catch { }
    }

It prints successful one time ,when pressing to print next time it throws and exception
Method ClaimDevice threw an exception. Attempt was made to perform an illegal or unsupported operation with the device, or an invalid parameter value was used.

any suggestion ?

Upvotes: 0

Views: 918

Answers (1)

Tamer Hatoum
Tamer Hatoum

Reputation: 49

Since the Release command is not being effective and may Claim command is throwing an error every time I am loading my form because it is being Claimed before.

So I have Create a separate Class Called "createPOS" 

         class createPOS
{
 public  static PosExplorer explorer;
  public  static PosPrinter kitchenPrinter;
  public static void createPos()
  {
      explorer = new PosExplorer();
      DeviceInfo receiptPrinterDevice = explorer.GetDevice("PosPrinter", Properties.Settings.Default.KitchenPrinter); //May need to change this if you don't use a logicial name or use a different one.
      kitchenPrinter = (PosPrinter)explorer.CreateInstance(receiptPrinterDevice);
      kitchenPrinter.Open();
      kitchenPrinter.Claim(10000);
      kitchenPrinter.DeviceEnabled = true;
  }
      public static void Print(string text){
          if (kitchenPrinter.Claimed)
              PrintTextLine(kitchenPrinter, text);  // kitchenPrinter.PrintNormal(PrinterStation.Receipt, text ); //Print text, then a new line character.
       }
      private static void PrintTextLine(PosPrinter printer, string text)
      {
          if (text.Length < printer.RecLineChars)
              printer.PrintNormal(PrinterStation.Receipt, text + Environment.NewLine); //Print text, then a new line character.
          else if (text.Length > printer.RecLineChars)
              printer.PrintNormal(PrinterStation.Receipt, TruncateAt(text, printer.RecLineChars)); //Print exactly as many characters as the printer allows, truncating the rest, no new line character (printer will probably auto-feed for us)
          else if (text.Length == printer.RecLineChars)
              printer.PrintNormal(PrinterStation.Receipt, text + Environment.NewLine); //Print text, no new line character, printer will probably auto-feed for us.
      }
      private static string TruncateAt(string text, int maxWidth)
      {
          string retVal = text;
          if (text.Length > maxWidth)
              retVal = text.Substring(0, maxWidth);

          return retVal;
      }
  }

and On the Login form that it will only be accessed once I have initialized my printer 

     createPOS.createPos();

and on MainForm I have called the Printing Method :

        createPOS.Print("This allows me to Print Several times");

on that way I am able to print several times and even I navigate to other forms and come back that works fine.

Thank you guys.

Upvotes: 1

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