Stopwatch.ElapsedMilliseconds Propriété
Définition
Important
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Obtient le temps total écoulé mesuré par l'instance actuelle, en millisecondes.
public:
property long ElapsedMilliseconds { long get(); };public long ElapsedMilliseconds { get; }member this.ElapsedMilliseconds : int64Public ReadOnly Property ElapsedMilliseconds As LongValeur de propriété
Entier long en lecture seule qui représente le nombre total de millisecondes mesuré par l'instance actuelle.
Exemples
L’exemple suivant utilise la Stopwatch classe pour mesurer les performances de quatre implémentations différentes pour analyser un entier à partir d’une chaîne. Cet exemple de code fait partie d’un exemple plus grand fourni pour la Stopwatch classe .
void TimeOperations()
{
Int64 nanosecPerTick = (1000L * 1000L * 1000L) / Stopwatch::Frequency;
const long numIterations = 10000;
// Define the operation title names.
array<String^>^operationNames = {"Operation: Int32.Parse(\"0\")","Operation: Int32.TryParse(\"0\")","Operation: Int32.Parse(\"a\")","Operation: Int32.TryParse(\"a\")"};
// Time four different implementations for parsing
// an integer from a string.
for ( int operation = 0; operation <= 3; operation++ )
{
// Define variables for operation statistics.
Int64 numTicks = 0;
Int64 numRollovers = 0;
Int64 maxTicks = 0;
Int64 minTicks = Int64::MaxValue;
int indexFastest = -1;
int indexSlowest = -1;
Int64 milliSec = 0;
Stopwatch ^ time10kOperations = Stopwatch::StartNew();
// Run the current operation 10001 times.
// The first execution time will be tossed
// out, since it can skew the average time.
for ( int i = 0; i <= numIterations; i++ )
{
Int64 ticksThisTime = 0;
int inputNum;
Stopwatch ^ timePerParse;
switch ( operation )
{
case 0:
// Parse a valid integer using
// a try-catch statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch::StartNew();
try
{
inputNum = Int32::Parse( "0" );
}
catch ( FormatException^ )
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse->Stop();
ticksThisTime = timePerParse->ElapsedTicks;
break;
case 1:
// Parse a valid integer using
// the TryParse statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch::StartNew();
if ( !Int32::TryParse( "0", inputNum ) )
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse->Stop();
ticksThisTime = timePerParse->ElapsedTicks;
break;
case 2:
// Parse an invalid value using
// a try-catch statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch::StartNew();
try
{
inputNum = Int32::Parse( "a" );
}
catch ( FormatException^ )
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse->Stop();
ticksThisTime = timePerParse->ElapsedTicks;
break;
case 3:
// Parse an invalid value using
// the TryParse statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch::StartNew();
if ( !Int32::TryParse( "a", inputNum ) )
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse->Stop();
ticksThisTime = timePerParse->ElapsedTicks;
break;
default:
break;
}
// Skip over the time for the first operation,
// just in case it caused a one-time
// performance hit.
if ( i == 0 )
{
time10kOperations->Reset();
time10kOperations->Start();
}
else
{
// Update operation statistics
// for iterations 1-10001.
if ( maxTicks < ticksThisTime )
{
indexSlowest = i;
maxTicks = ticksThisTime;
}
if ( minTicks > ticksThisTime )
{
indexFastest = i;
minTicks = ticksThisTime;
}
numTicks += ticksThisTime;
if ( numTicks < ticksThisTime )
{
// Keep track of rollovers.
numRollovers++;
}
}
}
// Display the statistics for 10000 iterations.
time10kOperations->Stop();
milliSec = time10kOperations->ElapsedMilliseconds;
Console::WriteLine();
Console::WriteLine( "{0} Summary:", operationNames[ operation ] );
Console::WriteLine( " Slowest time: #{0}/{1} = {2} ticks", indexSlowest, numIterations, maxTicks );
Console::WriteLine( " Fastest time: #{0}/{1} = {2} ticks", indexFastest, numIterations, minTicks );
Console::WriteLine( " Average time: {0} ticks = {1} nanoseconds", numTicks / numIterations, (numTicks * nanosecPerTick) / numIterations );
Console::WriteLine( " Total time looping through {0} operations: {1} milliseconds", numIterations, milliSec );
}
}
private static void TimeOperations()
{
long nanosecPerTick = (1000L*1000L*1000L) / Stopwatch.Frequency;
const long numIterations = 10000;
// Define the operation title names.
String [] operationNames = {"Operation: Int32.Parse(\"0\")",
"Operation: Int32.TryParse(\"0\")",
"Operation: Int32.Parse(\"a\")",
"Operation: Int32.TryParse(\"a\")"};
// Time four different implementations for parsing
// an integer from a string.
for (int operation = 0; operation <= 3; operation++)
{
// Define variables for operation statistics.
long numTicks = 0;
long numRollovers = 0;
long maxTicks = 0;
long minTicks = Int64.MaxValue;
int indexFastest = -1;
int indexSlowest = -1;
long milliSec = 0;
Stopwatch time10kOperations = Stopwatch.StartNew();
// Run the current operation 10001 times.
// The first execution time will be tossed
// out, since it can skew the average time.
for (int i=0; i<=numIterations; i++)
{
long ticksThisTime = 0;
int inputNum;
Stopwatch timePerParse;
switch (operation)
{
case 0:
// Parse a valid integer using
// a try-catch statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch.StartNew();
try
{
inputNum = Int32.Parse("0");
}
catch (FormatException)
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse.Stop();
ticksThisTime = timePerParse.ElapsedTicks;
break;
case 1:
// Parse a valid integer using
// the TryParse statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch.StartNew();
if (!Int32.TryParse("0", out inputNum))
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse.Stop();
ticksThisTime = timePerParse.ElapsedTicks;
break;
case 2:
// Parse an invalid value using
// a try-catch statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch.StartNew();
try
{
inputNum = Int32.Parse("a");
}
catch (FormatException)
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse.Stop();
ticksThisTime = timePerParse.ElapsedTicks;
break;
case 3:
// Parse an invalid value using
// the TryParse statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch.StartNew();
if (!Int32.TryParse("a", out inputNum))
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse.Stop();
ticksThisTime = timePerParse.ElapsedTicks;
break;
default:
break;
}
// Skip over the time for the first operation,
// just in case it caused a one-time
// performance hit.
if (i == 0)
{
time10kOperations.Reset();
time10kOperations.Start();
}
else
{
// Update operation statistics
// for iterations 1-10000.
if (maxTicks < ticksThisTime)
{
indexSlowest = i;
maxTicks = ticksThisTime;
}
if (minTicks > ticksThisTime)
{
indexFastest = i;
minTicks = ticksThisTime;
}
numTicks += ticksThisTime;
if (numTicks < ticksThisTime)
{
// Keep track of rollovers.
numRollovers ++;
}
}
}
// Display the statistics for 10000 iterations.
time10kOperations.Stop();
milliSec = time10kOperations.ElapsedMilliseconds;
Console.WriteLine();
Console.WriteLine("{0} Summary:", operationNames[operation]);
Console.WriteLine(" Slowest time: #{0}/{1} = {2} ticks",
indexSlowest, numIterations, maxTicks);
Console.WriteLine(" Fastest time: #{0}/{1} = {2} ticks",
indexFastest, numIterations, minTicks);
Console.WriteLine(" Average time: {0} ticks = {1} nanoseconds",
numTicks / numIterations,
(numTicks * nanosecPerTick) / numIterations );
Console.WriteLine(" Total time looping through {0} operations: {1} milliseconds",
numIterations, milliSec);
}
}
Private Shared Sub TimeOperations()
Dim nanosecPerTick As Long = 1000000000 / Stopwatch.Frequency
Const numIterations As Long = 10000
' Define the operation title names.
Dim operationNames As String() = _
{"Operation: Int32.Parse(""0"")", _
"Operation: Int32.TryParse(""0"")", _
"Operation: Int32.Parse(""a"")", _
"Operation: Int32.TryParse(""a"")"}
' Time four different implementations for parsing
' an integer from a string.
Dim operation As Integer
For operation = 0 To 3
' Define variables for operation statistics.
Dim numTicks As Long = 0
Dim numRollovers As Long = 0
Dim maxTicks As Long = 0
Dim minTicks As Long = Int64.MaxValue
Dim indexFastest As Integer = - 1
Dim indexSlowest As Integer = - 1
Dim milliSec As Long = 0
Dim time10kOperations As Stopwatch = Stopwatch.StartNew()
' Run the current operation 10001 times.
' The first execution time will be tossed
' out, since it can skew the average time.
Dim i As Integer
For i = 0 To numIterations
Dim ticksThisTime As Long = 0
Dim inputNum As Integer
Dim timePerParse As Stopwatch
Select Case operation
Case 0
' Parse a valid integer using
' a try-catch statement.
' Start a new stopwatch timer.
timePerParse = Stopwatch.StartNew()
Try
inputNum = Int32.Parse("0")
Catch e As FormatException
inputNum = 0
End Try
' Stop the timer, and save the
' elapsed ticks for the operation.
timePerParse.Stop()
ticksThisTime = timePerParse.ElapsedTicks
Case 1
' Parse a valid integer using
' the TryParse statement.
' Start a new stopwatch timer.
timePerParse = Stopwatch.StartNew()
If Not Int32.TryParse("0", inputNum) Then
inputNum = 0
End If
' Stop the timer, and save the
' elapsed ticks for the operation.
timePerParse.Stop()
ticksThisTime = timePerParse.ElapsedTicks
Case 2
' Parse an invalid value using
' a try-catch statement.
' Start a new stopwatch timer.
timePerParse = Stopwatch.StartNew()
Try
inputNum = Int32.Parse("a")
Catch e As FormatException
inputNum = 0
End Try
' Stop the timer, and save the
' elapsed ticks for the operation.
timePerParse.Stop()
ticksThisTime = timePerParse.ElapsedTicks
Case 3
' Parse an invalid value using
' the TryParse statement.
' Start a new stopwatch timer.
timePerParse = Stopwatch.StartNew()
If Not Int32.TryParse("a", inputNum) Then
inputNum = 0
End If
' Stop the timer, and save the
' elapsed ticks for the operation.
timePerParse.Stop()
ticksThisTime = timePerParse.ElapsedTicks
Case Else
End Select
' Skip over the time for the first operation,
' just in case it caused a one-time
' performance hit.
If i = 0 Then
time10kOperations.Reset()
time10kOperations.Start()
Else
' Update operation statistics
' for iterations 1-10001.
If maxTicks < ticksThisTime Then
indexSlowest = i
maxTicks = ticksThisTime
End If
If minTicks > ticksThisTime Then
indexFastest = i
minTicks = ticksThisTime
End If
numTicks += ticksThisTime
If numTicks < ticksThisTime Then
' Keep track of rollovers.
numRollovers += 1
End If
End If
Next i
' Display the statistics for 10000 iterations.
time10kOperations.Stop()
milliSec = time10kOperations.ElapsedMilliseconds
Console.WriteLine()
Console.WriteLine("{0} Summary:", operationNames(operation))
Console.WriteLine(" Slowest time: #{0}/{1} = {2} ticks", _
indexSlowest, numIterations, maxTicks)
Console.WriteLine(" Fastest time: #{0}/{1} = {2} ticks", _
indexFastest, numIterations, minTicks)
Console.WriteLine(" Average time: {0} ticks = {1} nanoseconds", _
numTicks / numIterations, numTicks * nanosecPerTick / numIterations)
Console.WriteLine(" Total time looping through {0} operations: {1} milliseconds", _
numIterations, milliSec)
Next operation
End Sub
End Class
Remarques
Cette propriété représente le temps écoulé arrondi à la valeur entière de milliseconde la plus proche. Pour des mesures plus précises, utilisez les Elapsed propriétés ou ElapsedTicks .
Vous pouvez interroger les propriétés Elapsed, ElapsedMillisecondset ElapsedTicks pendant que le Stopwatch instance est en cours d’exécution ou arrêté. Les propriétés de temps écoulé augmentent régulièrement pendant l’exécution de Stopwatch ; elles restent constantes lorsque le instance est arrêté.
Par défaut, la valeur de temps écoulé d’un Stopwatch instance est égale au total de tous les intervalles de temps mesurés. Chaque appel à commence à Start compter au temps écoulé cumulé ; chaque appel met fin à Stop la mesure de l’intervalle actuel et fige la valeur du temps écoulé cumulé. Utilisez la Reset méthode pour effacer le temps cumulé écoulé dans un instance existant Stopwatch .
S’applique à
Voir aussi
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