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Task Class

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

MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.

Inheritance Hierarchy

System.Object
  Microsoft.Build.Utilities.Task
    Microsoft.Build.Tasks.GenerateManifestBase
    Microsoft.Build.Tasks.SignFile
    Microsoft.Build.Tasks.TaskExtension
    Microsoft.Build.Tasks.UpdateManifest
    Microsoft.Build.Utilities.ToolTask

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

Syntax

'Declaration
Public MustInherit Class Task _
    Implements ITask

public abstract class Task : ITask

public ref class Task abstract : ITask

[<AbstractClass>]
type Task =  
    class 
        interface ITask 
    end

public abstract class Task implements ITask

The Task type exposes the following members.

Constructors

  Name Description
Protected method Task() Initializes a new instance of the Task class.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Protected method Task(ResourceManager) Initializes a new instance of the Task class with the specified TaskResources.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Protected method Task(ResourceManager, String) Initializes a new instance of the Task class with the specified TaskResources and HelpKeywordPrefix.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.

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Properties

  Name Description
Public property BuildEngine Gets or sets the instance of the IBuildEngine object used by the task.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Public property BuildEngine2 Gets the instance of the IBuildEngine2 object used by the task.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Public property BuildEngine3 Gets the instance of the IBuildEngine3 object used by the task.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Public property BuildEngine4 Gets the instance of the IBuildEngine4 object used by the task.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Protected property HelpKeywordPrefix Gets or sets the prefix used to compose Help keywords from resource names.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Public property HostObject Gets or sets the host object associated with the task.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Public property Log Gets an instance of a TaskLoggingHelper class containing task logging methods.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Protected property TaskResources Gets or sets the culture-specific resources associated with the task.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.

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Methods

  Name Description
Public method Equals (Inherited from Object.)
Public method Execute When overridden in a derived class, executes the task.MSBuild is now included in Visual Studio instead of the .NET Framework. You can use MSBuild 12.0 side-by-side with versions previously deployed with the .NET Framework.For more information, see What's New in MSBuild 12.0.
Protected method Finalize (Inherited from Object.)
Public method GetHashCode (Inherited from Object.)
Public method GetType (Inherited from Object.)
Protected method MemberwiseClone (Inherited from Object.)
Public method ToString (Inherited from Object.)

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Remarks

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.

Examples

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;
        }
    }
}

Thread Safety

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

See Also

Reference

Microsoft.Build.Utilities Namespace