TimeSpan.FromHours(Double) TimeSpan.FromHours(Double) TimeSpan.FromHours(Double) TimeSpan.FromHours(Double) Method

Definizione

Restituisce un oggetto TimeSpan che rappresenta un numero di ore specificato, in cui la specifica è approssimata al millisecondo più vicino.Returns a TimeSpan that represents a specified number of hours, where the specification is accurate to the nearest millisecond.

public:
 static TimeSpan FromHours(double value);
public static TimeSpan FromHours (double value);
static member FromHours : double -> TimeSpan
Public Shared Function FromHours (value As Double) As TimeSpan

Parametri

value
Double Double Double Double

Numero di ore, approssimato al millisecondo più vicino.A number of hours accurate to the nearest millisecond.

Restituisce

Oggetto che rappresenta l'oggetto value.An object that represents value.

Eccezioni

value è minore di MinValue o maggiore di MaxValue.value is less than MinValue or greater than MaxValue.

In alternativa-or- value è PositiveInfinity.value is PositiveInfinity.

In alternativa-or- value è NegativeInfinity.value is NegativeInfinity.

Esempi

Nell'esempio seguente crea diversi TimeSpan degli oggetti mediante il FromHours (metodo).The following example creates several TimeSpan objects using the FromHours method.

// Example of the TimeSpan::FromHours( double ) method.
using namespace System;
void GenTimeSpanFromHours( double hours )
{
   
   // Create a TimeSpan object and TimeSpan string from 
   // a number of hours.
   TimeSpan interval = TimeSpan::FromHours( hours );
   String^ timeInterval = interval.ToString();
   
   // Pad the end of the TimeSpan string with spaces if it 
   // does not contain milliseconds.
   int pIndex = timeInterval->IndexOf( ':' );
   pIndex = timeInterval->IndexOf( '.', pIndex );
   if ( pIndex < 0 )
      timeInterval = String::Concat( timeInterval, "        " );

   Console::WriteLine( "{0,21}{1,26}", hours, timeInterval );
}

int main()
{
   Console::WriteLine( "This example of TimeSpan::FromHours( double )\n"
   "generates the following output.\n" );
   Console::WriteLine( "{0,21}{1,18}", "FromHours", "TimeSpan" );
   Console::WriteLine( "{0,21}{1,18}", "---------", "--------" );
   GenTimeSpanFromHours( 0.0000002 );
   GenTimeSpanFromHours( 0.0000003 );
   GenTimeSpanFromHours( 0.0012345 );
   GenTimeSpanFromHours( 12.3456789 );
   GenTimeSpanFromHours( 123456.7898765 );
   GenTimeSpanFromHours( 0.0002777 );
   GenTimeSpanFromHours( 0.0166666 );
   GenTimeSpanFromHours( 1 );
   GenTimeSpanFromHours( 24 );
   GenTimeSpanFromHours( 500.3389445 );
}

/*
This example of TimeSpan::FromHours( double )
generates the following output.

            FromHours          TimeSpan
            ---------          --------
                2E-07          00:00:00.0010000
                3E-07          00:00:00.0010000
            0.0012345          00:00:04.4440000
           12.3456789          12:20:44.4440000
       123456.7898765     5144.00:47:23.5550000
            0.0002777          00:00:01
            0.0166666          00:01:00
                    1          01:00:00
                   24        1.00:00:00
          500.3389445       20.20:20:20.2000000
*/
// Example of the TimeSpan.FromHours( double ) method.
using System;

class FromHoursDemo
{
    static void GenTimeSpanFromHours( double hours )
    {
        // Create a TimeSpan object and TimeSpan string from 
        // a number of hours.
        TimeSpan    interval = TimeSpan.FromHours( hours );
        string      timeInterval = interval.ToString( );

        // Pad the end of the TimeSpan string with spaces if it 
        // does not contain milliseconds.
        int pIndex = timeInterval.IndexOf( ':' );
        pIndex = timeInterval.IndexOf( '.', pIndex );
        if( pIndex < 0 )   timeInterval += "        ";

        Console.WriteLine( "{0,21}{1,26}", hours, timeInterval );
    } 

    static void Main( )
    {
        Console.WriteLine(
            "This example of TimeSpan.FromHours( double )\n" +
            "generates the following output.\n" );
        Console.WriteLine( "{0,21}{1,18}",
            "FromHours", "TimeSpan" );
        Console.WriteLine( "{0,21}{1,18}", 
            "---------", "--------" );

        GenTimeSpanFromHours( 0.0000002 );
        GenTimeSpanFromHours( 0.0000003 );
        GenTimeSpanFromHours( 0.0012345 );
        GenTimeSpanFromHours( 12.3456789 );
        GenTimeSpanFromHours( 123456.7898765 );
        GenTimeSpanFromHours( 0.0002777 );
        GenTimeSpanFromHours( 0.0166666 );
        GenTimeSpanFromHours( 1 );
        GenTimeSpanFromHours( 24 );
        GenTimeSpanFromHours( 500.3389445 );
    } 
} 

/*
This example of TimeSpan.FromHours( double )
generates the following output.

            FromHours          TimeSpan
            ---------          --------
                2E-07          00:00:00.0010000
                3E-07          00:00:00.0010000
            0.0012345          00:00:04.4440000
           12.3456789          12:20:44.4440000
       123456.7898765     5144.00:47:23.5550000
            0.0002777          00:00:01
            0.0166666          00:01:00
                    1          01:00:00
                   24        1.00:00:00
          500.3389445       20.20:20:20.2000000
*/ 
' Example of the TimeSpan.FromHours( Double ) method.
Imports System
Imports Microsoft.VisualBasic

Module FromHoursDemo

    Sub GenTimeSpanFromHours( hours As Double )

        ' Create a TimeSpan object and TimeSpan string from 
        ' a number of hours.
        Dim interval As TimeSpan = _
            TimeSpan.FromHours( hours )
        Dim timeInterval As String = interval.ToString( )

        ' Pad the end of the TimeSpan string with spaces if it 
        ' does not contain milliseconds.
        Dim pIndex As Integer = timeInterval.IndexOf( ":"c )
        pIndex = timeInterval.IndexOf( "."c, pIndex )
        If pIndex < 0 Then  timeInterval &= "        "

        Console.WriteLine( "{0,21}{1,26}", hours, timeInterval )
    End Sub 

    Sub Main( )

        Console.WriteLine( "This example of " & _
            "TimeSpan.FromHours( Double )" & _
            vbCrLf & "generates the following output." & vbCrLf )
        Console.WriteLine( "{0,21}{1,18}", _
            "FromHours", "TimeSpan" )    
        Console.WriteLine( "{0,21}{1,18}", _
            "---------", "--------" )    

        GenTimeSpanFromHours( 0.0000002 )
        GenTimeSpanFromHours( 0.0000003 )
        GenTimeSpanFromHours( 0.0012345 )
        GenTimeSpanFromHours( 12.3456789 )
        GenTimeSpanFromHours( 123456.7898765 )
        GenTimeSpanFromHours( 0.0002777 )
        GenTimeSpanFromHours( 0.0166666 )
        GenTimeSpanFromHours( 1 )
        GenTimeSpanFromHours( 24 )
        GenTimeSpanFromHours( 500.3389445 )
    End Sub 
End Module 

' This example of TimeSpan.FromHours( Double )
' generates the following output.
' 
'             FromHours          TimeSpan
'             ---------          --------
'                 2E-07          00:00:00.0010000
'                 3E-07          00:00:00.0010000
'             0.0012345          00:00:04.4440000
'            12.3456789          12:20:44.4440000
'        123456.7898765     5144.00:47:23.5550000
'             0.0002777          00:00:01
'             0.0166666          00:01:00
'                     1          01:00:00
'                    24        1.00:00:00
'           500.3389445       20.20:20:20.2000000

Commenti

Il value parametro viene convertito in millisecondi, che viene convertito in tick, e tale numero di segni di graduazione viene utilizzato per inizializzare la nuova TimeSpan.The value parameter is converted to milliseconds, which is converted to ticks, and that number of ticks is used to initialize the new TimeSpan. Pertanto, value verrà considerata solo precisione al millisecondo più vicino.Therefore, value will only be considered accurate to the nearest millisecond. Si noti che, a causa della perdita di precisione del Double tipo di dati, questa conversione può generare un' OverflowException per i valori che sono prossimi a ma comunque nell'intervallo di entrambi MinValue o MaxValue.Note that, because of the loss of precision of the Double data type, this conversion can generate an OverflowException for values that are near to but still in the range of either MinValue or MaxValue. Ad esempio, ciò causa un OverflowException durante il seguente tentativo di creare un'istanza di un TimeSpan oggetto.For example, this causes an OverflowException in the following attempt to instantiate a TimeSpan object.

// The following throws an OverflowException at runtime
TimeSpan maxSpan = TimeSpan.FromHours(TimeSpan.MaxValue.TotalHours);
' The following throws an OverflowException at runtime
Dim maxSpan As TimeSpan = TimeSpan.FromHours(TimeSpan.MaxValue.TotalHours)

Si applica a

Vedi anche