Nullable<T>.ToString メソッド

定義

現在の Nullable<T> オブジェクトの値のテキスト形式を返します。Returns the text representation of the value of the current Nullable<T> object.

public:
 override System::String ^ ToString();
public override string ToString ();
override this.ToString : unit -> string
Public Overrides Function ToString () As String

戻り値

Nullable<T> プロパティが true の場合は、現在の HasValue オブジェクトの値のテキスト形式。HasValue プロパティが false の場合は空の文字列 ("")。The text representation of the value of the current Nullable<T> object if the HasValue property is true, or an empty string ("") if the HasValue property is false.

次のコード例では、現在Nullable<T>のオブジェクトの値を表示します。The following code example displays the value of the current Nullable<T> object.

// This code example demonstrates the 
// Nullable<T>.ToString method.

using System;

class Sample 
{
    public static void Main() 
    {
    DateTime? nullableDate;

// Display the current date and time.
    nullableDate = DateTime.Now;
    Display("1)", nullableDate);

// Assign null (Nothing in Visual Basic) to nullableDate, then 
// display its value.
    nullableDate = null;
    Display("2)", nullableDate);
    }

// Display the text representation of a nullable DateTime.
    public static void Display(string title, DateTime? dspDT)
    {
    string msg = dspDT.ToString();

    Console.Write("{0} ", title);
    if (String.IsNullOrEmpty(msg))
        Console.WriteLine("The nullable DateTime has no defined value.");
    else
        Console.WriteLine("The current date and time is {0}.", msg);
    }
}

/*
This code example produces the following results:

1) The current date and time is 4/19/2005 8:28:14 PM.
2) The nullable DateTime has no defined value.

*/
' This code example demonstrates the 
' Nullable<T>.ToString method.

Class Sample
    Public Shared Sub Main() 
        Dim nullableDate As Nullable(Of DateTime)
    ' Display the current date and time.
        nullableDate = DateTime.Now
        Display("1)", nullableDate)
        
    ' Assign null (Nothing in Visual Basic) to nullableDate, then 
    ' display its value.
        nullableDate = Nothing
        Display("2)", nullableDate)
    End Sub

    '  Display the text representation of a nullable DateTime.
    Public Shared Sub Display(ByVal title As String, _
                              ByVal dspDT As Nullable(Of DateTime))
        Dim msg As String = dspDT.ToString()

        Console.Write("{0} ", title)
        If String.IsNullOrEmpty(msg) Then
            Console.WriteLine("The nullable DateTime has no defined value.")
        Else
            Console.WriteLine("The current date and time is {0}.", msg)
        End If
    End Sub
End Class

'This code example produces the following results:
'
'1) The current date and time is 4/19/2005 8:28:14 PM.
'2) The nullable DateTime has no defined value.
'

注釈

プロパティToStringは、 Valueプロパティによって返されるToStringオブジェクトのプロパティを呼び出すことによって取得された文字列を返します。The ToString property returns the string yielded by calling the ToString property of the object returned by the Value property.

適用対象