MessageQueue.Exists Method

The Exists(String) method determines whether a Message Queuing queue exists at a specified path. No method exists to determine whether a queue with a specified format name exists. For more information about the format name syntax and other path syntax forms, see the Path property.)

Exists(String) is an expensive operation. Use it only when it is necessary within the application.

Note
The Exists(String) method does not support the FormatName prefix.

The syntax for the path parameter depends on the type of queue, as shown in the following table.

Exists(String) cannot be called to verify the existence of a remote private queue.

For more syntax, see the Path property.

Alternatively, you can use the Label to describe the queue path.

The following table shows whether this method is available in various Workgroup modes.

The following code example verifies whether a Message Queuing queue exists, and then deletes it.

using System;
using System.Messaging;

namespace MyProject
{
	/// <summary> 
	/// Provides a container class for the example. 
	/// </summary> 
	public class MyNewQueue
	{

		//************************************************** 
		// Provides an entry point into the application. 
		//		  
		// This example verifies existence and attempts to  
		// delete a queue. 
		//************************************************** 

		public static void Main()
		{

			// Determine whether the queue exists. 
			if (MessageQueue.Exists(".\\myQueue"))
			{
				try
				{
					// Delete the queue.
					MessageQueue.Delete(".\\myQueue");
				}
				catch(MessageQueueException e)
				{
					if(e.MessageQueueErrorCode == 
						MessageQueueErrorCode.AccessDenied)
					{
						Console.WriteLine("Access is denied. " + 
							"Queue might be a system queue.");
					}

					// Handle other sources of MessageQueueException.
				}

			}
		
			return;
		}

	}
}

.NET Framework

.NET Framework Client Profile

• Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference