แก้ไข

แชร์ผ่าน


DateTimeOffset.LessThanOrEqual(DateTimeOffset, DateTimeOffset) Operator

Definition

Determines whether one specified DateTimeOffset object is less than a second specified DateTimeOffset object.

public:
 static bool operator <=(DateTimeOffset left, DateTimeOffset right);
public static bool operator <= (DateTimeOffset left, DateTimeOffset right);
static member ( <= ) : DateTimeOffset * DateTimeOffset -> bool
Public Shared Operator <= (left As DateTimeOffset, right As DateTimeOffset) As Boolean

Parameters

left
DateTimeOffset

The first object to compare.

right
DateTimeOffset

The second object to compare.

Returns

true if the UtcDateTime value of left is earlier than the UtcDateTime value of right; otherwise, false.

Remarks

The LessThanOrEqual method defines the operation of the less than or equal to operator for DateTimeOffset objects. It enables code such as the following:

DateTimeOffset date1 = new DateTimeOffset(2007, 6, 3, 14, 45, 0,
             new TimeSpan(-7, 0, 0));
DateTimeOffset date2 = new DateTimeOffset(2007, 6, 3, 15, 45, 0,
             new TimeSpan(-7, 0, 0));
DateTimeOffset date3 = new DateTimeOffset(date1.DateTime,
             new TimeSpan(-6, 0, 0));
DateTimeOffset date4 = date1;
Console.WriteLine(date1 <= date2);        // Displays True
Console.WriteLine(date1 <= date3);        // Displays False
Console.WriteLine(date1 <= date4);        // Displays True
let date1 =
    DateTimeOffset(2007, 6, 3, 14, 45, 0, TimeSpan(-7, 0, 0))

let date2 =
    DateTimeOffset(2007, 6, 3, 15, 45, 0, TimeSpan(-7, 0, 0))

let date3 =
    DateTimeOffset(date1.DateTime, TimeSpan(-6, 0, 0))

let date4 = date1
printfn $"{date1 <= date2}" // Displays True
printfn $"{date1 <= date3}" // Displays False
printfn $"{date1 <= date4}" // Displays True
Dim date1 As New DateTimeOffset(#6/3/2007 2:45PM#, _
             New TimeSpan(-7, 0, 0))
Dim date2 As New DateTimeOffset(#6/3/2007 3:45PM#, _
             New TimeSpan(-7, 0, 0))
Dim date3 As New DateTimeOffset(date1.DateTime, _
             New TimeSpan(-6, 0, 0))
Dim date4 As DateTimeOffset = date1
Console.WriteLine(date1 <= date2)        ' Displays True
Console.WriteLine(date1 <= date3)        ' Displays False
Console.WriteLine(date1 <= date4)        ' Displays True

Languages that do not support custom operators can call the Compare method instead. Some languages can also call the LessThanOrEqual method directly, as the following example shows.

Dim date1 As New DateTimeOffset(#6/3/2007 2:45PM#, _
             New TimeSpan(-7, 0, 0))
Dim date2 As New DateTimeOffset(#6/3/2007 3:45PM#, _
             New TimeSpan(-7, 0, 0))
Dim date3 As New DateTimeOffset(date1.DateTime, _
             New TimeSpan(-6, 0, 0))
Dim date4 As DateTimeOffset = date1
Console.WriteLine(DateTimeOffset.op_LessThanOrEqual(date1, date2))   ' Displays True
Console.WriteLine(DateTimeOffset.op_LessThanOrEqual(date1, date3)) ' Displays False
Console.WriteLine(DateTimeOffset.op_LessThanOrEqual(date1, date4)) ' Displays True

Before evaluating the left and right operands, the operator converts both values to Coordinated Universal Time (UTC). The operation is equivalent to the following:

return left.UtcDateTime <= right.UtcDateTime;
left.UtcDateTime <= right.UtcDateTime
Return left.UtcDateTime <= right.UtcDateTime

The equivalent method for this operator is DateTimeOffset.Compare(DateTimeOffset, DateTimeOffset)

Applies to