DateTime.MinValue Champ

public: static initonly DateTime MinValue;

public static readonly DateTime MinValue;

 staticval mutable MinValue : DateTime

Public Shared ReadOnly MinValue As DateTime 

Valeur de champ

Exemples

L’exemple suivant instancie un objet DateTime en passant à son constructeur une valeur Int64 qui représente un nombre de graduations.The following example instantiates a DateTime object by passing its constructor an Int64 value that represents a number of ticks. Avant d’appeler le constructeur, l’exemple vérifie que cette valeur est supérieure ou égale à DateTime.MinValue.Ticks et inférieure ou égale à DateTime.MaxValue.Ticks.Before invoking the constructor, the example ensures that this value is greater than or equal to DateTime.MinValue.Ticks and less than or equal to DateTime.MaxValue.Ticks. Si ce n’est pas le cas, il lève une ArgumentOutOfRangeException.If not, it throws an ArgumentOutOfRangeException.

// Attempt to assign an out-of-range value to a DateTime constructor.
long numberOfTicks = Int64.MaxValue;
DateTime validDate;

// Validate the value.
if (numberOfTicks >= DateTime.MinValue.Ticks &&
    numberOfTicks <= DateTime.MaxValue.Ticks) 
   validDate = new DateTime(numberOfTicks);
else if (numberOfTicks < DateTime.MinValue.Ticks) 
   Console.WriteLine("{0:N0} is less than {1:N0} ticks.", 
                     numberOfTicks, 
                     DateTime.MinValue.Ticks);      
else
   Console.WriteLine("{0:N0} is greater than {1:N0} ticks.", 
                     numberOfTicks,
                     DateTime.MaxValue.Ticks);
// The example displays the following output:
//   9,223,372,036,854,775,807 is greater than 3,155,378,975,999,999,999 ticks.

' Attempt to assign an out-of-range value to a DateTime constructor.
Dim numberOfTicks As Long = Int64.MaxValue
Dim validDate As Date

' Validate the value.
If numberOfTicks >= Date.MinValue.Ticks And _
   numberOfTicks <= Date.MaxValue.Ticks Then
   validDate = New Date(numberOfTicks)
ElseIf numberOfTicks < Date.MinValue.Ticks Then
   Console.WriteLine("{0:N0} is less than {1:N0} ticks.", 
                     numberOfTicks, 
                     DateTime.MinValue.Ticks)      
Else                                                   
   Console.WriteLine("{0:N0} is greater than {1:N0} ticks.", 
                     numberOfTicks, 
                     DateTime.MaxValue.Ticks)     
End If
' The example displays the following output:
'   9,223,372,036,854,775,807 is greater than 3,155,378,975,999,999,999 ticks.      

Remarques

La valeur de cette constante est équivalente à 00:00:00.0000000 UTC, le 1er janvier 0001, dans le calendrier grégorien.The value of this constant is equivalent to 00:00:00.0000000 UTC, January 1, 0001, in the Gregorian calendar.

MinValue définit la date et l’heure assignées à une variable DateTime non initialisée.MinValue defines the date and time that is assigned to an uninitialized DateTime variable. L'exemple suivant illustre ce comportement.The following example illustrates this.

// Define an uninitialized date.
DateTime date1 = new DateTime();
Console.Write(date1);
if (date1.Equals(DateTime.MinValue))
   Console.WriteLine("  (Equals Date.MinValue)");
// The example displays the following output:
//    1/1/0001 12:00:00 AM  (Equals Date.MinValue)

' Define an uninitialized date.
Dim date1 As Date
Console.Write(date1)
If date1.Equals(Date.MinValue) Then _
   Console.WriteLine("  (Equals Date.MinValue)")
' The example displays the following output:
'    1/1/0001 12:00:00 AM  (Equals Date.MinValue)

Les propriétés MinValue et MaxValue peuvent être utilisées pour garantir qu’une valeur se trouve dans la plage prise en charge avant de la passer à un constructeur DateTime.The MinValue and MaxValue properties can be used to ensure that a value lies within the supported range before passing it to a DateTime constructor. Le code de la section exemple illustre cette utilisation.The code in the Example section illustrates this usage.

S’applique à