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Task Class

When overridden in a derived form, provides functionality for tasks.

Namespace:  Microsoft.Build.Utilities
Assembly:  Microsoft.Build.Utilities (in Microsoft.Build.Utilities.dll)

public abstract class Task : ITask

This abstract class provides default implementations for the methods and properties of the ITask interface.

This class can only be instantiated in a derived form.

The following example shows the code for a task that creates one or more directories.

using System;
using System.IO;
using System.Security;
using System.Collections;
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;

namespace Microsoft.Build.Tasks
{
	/*
	 * Class: MakeDir
	 *
	 * An MSBuild task that creates one or more directories.
	 *
	 */ 
	public class MakeDir : Task
	{
	    // The Required attribute indicates the following to MSBuild: 
	    //	     - if the parameter is a scalar type, and it is not supplied, fail the build immediately 
	    //	     - if the parameter is an array type, and it is not supplied, pass in an empty array 
	    // In this case the parameter is an array type, so if a project fails to pass in a value for the  
            // Directories parameter, the task will get invoked, but this implementation will do nothing, 
            // because the array will be empty.
		[Required]
            // Directories to create. 
		public ITaskItem[] Directories
		{
			get
			{
				return directories;
			}

			set
			{
				directories = value;
			}
		}

		// The Output attribute indicates to MSBuild that the value of this property can be gathered after the 
		// task has returned from Execute(), if the project has an <Output> tag under this task's element for  
		// this property.
		[Output]
		// A project may need the subset of the inputs that were actually created, so make that available here. 
		public ITaskItem[] DirectoriesCreated
		{
			get
			{
				return directoriesCreated;
			}
		}

		private ITaskItem[] directories;
		private ITaskItem[] directoriesCreated;

		/// <summary> 
		/// Execute is part of the Microsoft.Build.Framework.ITask interface. 
		/// When it's called, any input parameters have already been set on the task's properties. 
		/// It returns true or false to indicate success or failure. 
		/// </summary> 
		public override bool Execute()
		{
			ArrayList items = new ArrayList();
			foreach (ITaskItem directory in Directories)
			{
				// ItemSpec holds the filename or path of an Item 
				if (directory.ItemSpec.Length > 0)
				{
					try
					{
						// Only log a message if we actually need to create the folder 
						if (!Directory.Exists(directory.ItemSpec))
						{
							Log.LogMessage(MessageImportance.Normal, "Creating directory " + directory.ItemSpec);
							Directory.CreateDirectory(directory.ItemSpec);
						}

						// Add to the list of created directories
						items.Add(directory);
					}
					// If a directory fails to get created, log an error, but proceed with the remaining  
					// directories. 
					catch (Exception ex)
					{
						if (ex is IOException
							|| ex is UnauthorizedAccessException
							|| ex is PathTooLongException
							|| ex is DirectoryNotFoundException
							|| ex is SecurityException)
						{
							Log.LogError("Error trying to create directory " + directory.ItemSpec + ". " + ex.Message);
						}
						else
						{
							throw;
						}
					}
				}
			}

			// Populate the "DirectoriesCreated" output items.
			directoriesCreated = (ITaskItem[])items.ToArray(typeof(ITaskItem));

			// Log.HasLoggedErrors is true if the task logged any errors -- even if they were logged  
			// from a task's constructor or property setter. As long as this task is written to always log an error 
			// when it fails, we can reliably return HasLoggedErrors. 
			return !Log.HasLoggedErrors;
		}
	}
}

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0

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