Item プロパティ

構文

'宣言
Public ReadOnly Default Property Item ( _
    index As Object _
) As Variable
    Get
'使用
Dim instance As Variables
Dim index As Object
Dim value As Variable

value = instance(index)

public Variable this[
    Object index
] { get; }

public:
property Variable^ default[Object^ index] {
    Variable^ get (Object^ index);
}

member Item : Variable

JScript はインデックス化されたプロパティの使用をサポートしていますが、新規の宣言はサポートしていません。

説明

Contains メソッドの呼び出しで true が返される場合は、Variables[index] 構文を使用することにより、コレクション内の指定した要素にアクセスできます。Contains メソッドから false が返される場合、このプロパティは例外をスローします。C# の場合、このプロパティは Variables クラスのインデクサとなります。

使用例

次のコード例では、変数をパッケージに追加します。このコード例では、さまざまなメソッドを使用して変数を検索し、その名前、値、および名前空間を出力します。

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Dts.Runtime;
namespace Adding_Variables
{
    class Program
    {
        static void Main(string[] args)
        {
            Application app = new Application();
            // Load a sample package that contains a variable that sets the file name.
            Package pkg = app.LoadPackage(@"C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx", null);
            Variables pkgVars = pkg.Variables;
            Variable myVar = pkg.Variables.Add("myCustomVar", false, "User", "3");

            // Verify whether the variable is in the collection now.
            Boolean hasMyVar = pkg.Variables.Contains("myCustomVar");
            Console.WriteLine("The variable was found? {0}", hasMyVar);

            // Loop over the collection using the foreach keyword.
            foreach (Variable pkgVar in pkgVars)
            {
                // Print variables only from the User namespace.
                if (pkgVar.Namespace == "User")
                {
                Console.WriteLine("Variable: {0}, {1}", pkgVar.Name, pkgVar.Value.ToString());
                 }
            }
            Console.WriteLine("---------------------------");
            // Loop over the collection using the Enumerator. 
            VariableEnumerator myEnum = pkg.Variables.GetEnumerator();
            int i = 0;
            while ((myEnum.MoveNext()) && (myEnum.Current != null))
                // Again, show only the variables in the User namespace.
                if (myEnum.Current.Namespace == "User")
                {                
                    Console.WriteLine("[{0}] {1}, {2}", i++, myEnum.Current.Name, myEnum.Current.Namespace);
                }

            myEnum.Reset();
            Console.WriteLine("---------------------------");

            //Using the Item method syntax of [x], obtain the
            // first entry in the collection.
            myVar = pkgVars[0];
            Console.WriteLine("The name and namespace of the first variable is: {0}, {1}", myVar.Name, myVar.Namespace);
            String nameOfFirstItem = pkgVars[0].Name;
            Console.WriteLine("The name of the first variable is: {0}", nameOfFirstItem);
            //}
        }
    }
}

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
Namespace Adding_Variables
    Class Program
        Shared  Sub Main(ByVal args() As String)
            Dim app As Application =  New Application() 
            ' Load a sample package that contains a variable that sets the file name.
            Dim pkg As Package =  app.LoadPackage("C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx",Nothing) 
            Dim pkgVars As Variables =  pkg.Variables 
            Dim myVar As Variable =  pkg.Variables.Add("myCustomVar",False,"User","3") 
 
            ' Verify whether the variable is in the collection now.
            Dim hasMyVar As Boolean =  pkg.Variables.Contains("myCustomVar") 
            Console.WriteLine("The variable was found? {0}", hasMyVar)
 
            ' Loop over the collection using the foreach keyword.
            Dim pkgVar As Variable
            For Each pkgVar In pkgVars
                ' Print variables only from the User namespace.
                If pkgVar.Namespace = "User" Then
                Console.WriteLine("Variable: {0}, {1}", pkgVar.Name, pkgVar.Value.ToString())
                End If
            Next
            Console.WriteLine("---------------------------")
            ' Loop over the collection using the Enumerator. 
            Dim myEnum As VariableEnumerator =  pkg.Variables.GetEnumerator() 
            Dim i As Integer =  0 
            While (myEnum.MoveNext()) &&(myEnum.Current <> Nothing)
                    Console.WriteLine("[{0}] {1}, {2}",i = Console.WriteLine("[{0}] {1}, {2}",i + 1
            End While
 
            myEnum.Reset()
            Console.WriteLine("---------------------------")
 
            'Using the Item method syntax of [x], obtain the
            ' first entry in the collection.
            myVar = pkgVars(0)
            Console.WriteLine("The name and namespace of the first variable is: {0}, {1}", myVar.Name, myVar.Namespace)
            Dim nameOfFirstItem As String =  pkgVars(0).Name 
            Console.WriteLine("The name of the first variable is: {0}", nameOfFirstItem)
            '}
        End Sub
    End Class
End Namespace

サンプルの出力 :

The variable was found?True

Variable: myCustomVar, 3

---------------------------

[0] myCustomVar, User

---------------------------

The name and namespace of the first variable is: CancelEvent, System

The name of the first variable is: CancelEvent

関連項目

参照