ITaskItem Rozhraní

Definice

Toto rozhraní definuje položku projektu, kterou lze spotřebovat a emitovat úkoly.This interface defines a project item that can be consumed and emitted by tasks.

public interface class ITaskItem
[System.Runtime.InteropServices.ComVisible(true)]
[System.Runtime.InteropServices.Guid("8661674F-2148-4F71-A92A-49875511C528")]
public interface ITaskItem
[<System.Runtime.InteropServices.ComVisible(true)>]
[<System.Runtime.InteropServices.Guid("8661674F-2148-4F71-A92A-49875511C528")>]
type ITaskItem = interface
Public Interface ITaskItem
Odvozené
Atributy

Příklady

Následující příklad ukazuje kód pro úlohu, která vytvoří jeden či více adresářů.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;
        }
    }
}

Poznámky

Počet ITaskItem objektů vytvořených během sestavení nemusí přesně odpovídat položkám deklarovaným v souboru projektu z následujících důvodů:The number of ITaskItem objects created during a build may not correspond exactly to items declared in a project file for the following reasons:

  • Úlohy někdy vytvářejí položky, které nebyly deklarovány v souboru projektu.Tasks sometimes create items that were not declared in the project file.

  • Kolekce položek může být deklarována v souboru projektu se zástupnými znaky, což může vytvořit mnoho položek, pokud je sestavena.An item collection can be declared in the project file with wildcards, which could create many items when built.

Vlastnosti

ItemSpec

Získá nebo nastaví položku "specifikace", např. pro položky založené na disku by to byla cesta k souboru.Gets or sets the item "specification" e.g. for disk-based items this would be the file path.

MetadataCount

Získá počet částí metadat na položce.Gets the number of pieces of metadata on the item. Zahrnuje vlastní i Vestavěná metadata.Includes both custom and built-in metadata.

MetadataNames

Získá názvy všech metadat položky.Gets the names of all the metadata on the item. Zahrnuje Vestavěná metadata, jako je "FullPath".Includes the built-in metadata like "FullPath".

Metody

CloneCustomMetadata()

Získat kolekci vlastních metadat.Get the collection of custom metadata. Nezahrnuje Vestavěná metadata.This does not include built-in metadata.

CopyMetadataTo(ITaskItem)

Umožňuje zkopírovat vlastní metadata u položky do jiné položky.Allows custom metadata on the item to be copied to another item.

GetMetadata(String)

Povoluje dotaz na hodnoty metadat na položce.Allows the values of metadata on the item to be queried.

RemoveMetadata(String)

Povoluje odebrání vlastních metadat nastavených u položky.Allows the removal of custom metadata set on the item.

SetMetadata(String, String)

Umožňuje nastavit u položky vlastní metadata.Allows a piece of custom metadata to be set on the item.

Platí pro