ITaskItem Interfejs

Definicja

Ten interfejs definiuje element projektu, który może być używany i emitowany przez zadania.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
Pochodne
Atrybuty

Przykłady

Poniższy przykład przedstawia kod dla zadania, które tworzy jeden lub więcej katalogów.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;
        }
    }
}

Uwagi

Liczba ITaskItem obiektów utworzonych podczas kompilacji może nie odpowiadać dokładnie elementom zadeklarowanym w pliku projektu z następujących powodów:The number of ITaskItem objects created during a build may not correspond exactly to items declared in a project file for the following reasons:

  • Czasami zadania tworzą elementy, które nie zostały zadeklarowane w pliku projektu.Tasks sometimes create items that were not declared in the project file.

  • Kolekcja elementów może być zadeklarowana w pliku projektu z symbolami wieloznacznymi, które mogą tworzyć wiele elementów po skompilowaniu.An item collection can be declared in the project file with wildcards, which could create many items when built.

Właściwości

ItemSpec

Pobiera lub ustawia element "Specyfikacja", np. dla elementów opartych na dyskach, to ścieżka do pliku.Gets or sets the item "specification" e.g. for disk-based items this would be the file path.

MetadataCount

Pobiera liczbę fragmentów metadanych dla elementu.Gets the number of pieces of metadata on the item. Obejmuje niestandardowe i wbudowane metadane.Includes both custom and built-in metadata.

MetadataNames

Pobiera nazwy wszystkich metadanych dla elementu.Gets the names of all the metadata on the item. Zawiera wbudowane metadane, takie jak "FullPath".Includes the built-in metadata like "FullPath".

Metody

CloneCustomMetadata()

Pobierz kolekcję metadanych niestandardowych.Get the collection of custom metadata. Nie obejmuje to wbudowanych metadanych.This does not include built-in metadata.

CopyMetadataTo(ITaskItem)

Umożliwia skopiowanie niestandardowych metadanych elementu do innego elementu.Allows custom metadata on the item to be copied to another item.

GetMetadata(String)

Zezwala na wartości metadanych dla elementu, który ma być wysyłany do zapytania.Allows the values of metadata on the item to be queried.

RemoveMetadata(String)

Umożliwia usunięcie niestandardowych metadanych dla elementu.Allows the removal of custom metadata set on the item.

SetMetadata(String, String)

Umożliwia ustawienie dla elementu metadanych niestandardowych.Allows a piece of custom metadata to be set on the item.

Dotyczy