How can I check if there is a default printer (Windows)?

Question

Is there a API or registry key which I can use from applications (native, Java or .Net) to check if the currently logged on user has configured a default printer?

Update: Many thanks for the answers so far! According to the KB article http://support.microsoft.com/kb/156212, the registry entry (read/write) is only documented up to Windows 2000. Is there a Win API method in newer versions for native access?

Answer 1

In .NET this code works for me:

public static string DefaultPrinterName()
{
  string functionReturnValue = null;
  System.Drawing.Printing.PrinterSettings oPS 
    = new System.Drawing.Printing.PrinterSettings();

  try
  {
    functionReturnValue = oPS.PrinterName;
  }
  catch (System.Exception ex)
  {
    functionReturnValue = "";
  }
  finally
  {
    oPS = null;
  }
  return functionReturnValue;
}

From: http://in.answers.yahoo.com/question/index?qid=20070920032312AAsSaPx

Answer 2

There is a Java API to get the default printer:

PrintService defaultPrinter = PrintServiceLookup.lookupDefaultPrintService();

It returns null if there is no default Printer or Service. That can be used as a test.

---

Old answer

The information can be found in the registry. You can't access the registry with plain Java, but there are JNDI solutions around for this problem. So basically you have to test, if a certain key exists in the registry. And, as a bonus, if you've come so far, you should even be able to get the name of the default printer :)

Further Reading:

• Changing a User's Default Printer in the Registry
• jRegistryKey (as an example, there are more solutions around)

Answer 3

There is a function in the unmanaged Print Spooler API winspool.drv. You can call the GetDefaultPrinter function to return the name of the default printer.

This is the P/Invoke signature for the unmanaged function:

[DllImport("winspool.drv", CharSet=CharSet.Auto, SetLastError=true)]
private static extern bool GetDefaultPrinter(
    StringBuilder buffer,
    ref int bufferSize);

Use this function to determine whether a default printer is set:

    public static bool IsDefaultPrinterAssigned()
    {
        //initialise size at 0, used to determine size of the buffer
        int size = 0;

        //for first call provide a null StringBuilder and 0 size to determine buffer size
        //return value will be false, as the call actually fails internally setting the size to the size of the buffer
        GetDefaultPrinter(null, ref size);

        if (size != 0)
        {
            //default printer set
            return true;
        }

        return false;
    }

Use this function to return the default printer name, returns empty string if default is not set:

    public static string GetDefaultPrinterName()
    {
        //initialise size at 0, used to determine size of the buffer
        int size = 0;

        //for first call provide a null StringBuilder and 0 size to determine buffer size
        //return value will be false, as the call actually fails internally setting the size to the size of the buffer
        GetDefaultPrinter(null, ref size);

        if (size == 0)
        {
            //no default printer set
            return "";
        }

        StringBuilder printerNameStringBuilder = new StringBuilder(size);

        bool success = GetDefaultPrinter(printerNameStringBuilder, ref size);

        if (!success)
        {
            throw new Win32Exception(Marshal.GetLastWin32Error());
        }

        return printerNameStringBuilder.ToString();
    }

Full code to test in a Console Application:

using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Text;

namespace DefaultPrinter
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(IsDefaultPrinterAssigned());
            Console.WriteLine(GetDefaultPrinterName());
            Console.ReadLine();
        }

        [DllImport("winspool.drv", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern bool GetDefaultPrinter(
            StringBuilder buffer,
            ref int bufferSize);

        public static bool IsDefaultPrinterAssigned()
        {
            //initialise size at 0, used to determine size of the buffer
            int size = 0;

            //for first call provide a null StringBuilder to and 0 size to determine buffer size
            //return value will be false, as the call actually fails internally setting the size to the size of the buffer
            GetDefaultPrinter(null, ref size);

            if (size != 0)
            {
                //default printer set
                return true;
            }

            return false;
        }

        public static string GetDefaultPrinterName()
        {
            //initialise size at 0, used to determine size of the buffer
            int size = 0;

            //for first call provide a null StringBuilder to and 0 size to determine buffer size
            //return value will be false, as the call actually fails internally setting the size to the size of the buffer
            GetDefaultPrinter(null, ref size);

            if (size == 0)
            {
                //no default printer set
                return "";
            }

            StringBuilder printerNameStringBuilder = new StringBuilder(size);

            bool success = GetDefaultPrinter(printerNameStringBuilder, ref size);

            if (!success)
            {
                throw new Win32Exception(Marshal.GetLastWin32Error());
            }

            return printerNameStringBuilder.ToString();
        }
    }
}