Stopwatch.ElapsedMilliseconds Propiedad
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Obtiene el tiempo total transcurrido medido por la instancia actual, en milisegundos.
public:
property long ElapsedMilliseconds { long get(); };public long ElapsedMilliseconds { get; }member this.ElapsedMilliseconds : int64Public ReadOnly Property ElapsedMilliseconds As LongValor de propiedad
Entero largo de solo lectura que representa el número total de milisegundos medido por la instancia actual.
Ejemplos
En el ejemplo siguiente se usa la Stopwatch clase para medir el rendimiento de cuatro implementaciones diferentes para analizar un entero de una cadena. Este ejemplo de código forma parte de un ejemplo más grande proporcionado para la Stopwatch clase .
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
Comentarios
Esta propiedad representa el tiempo transcurrido redondeado hacia abajo hasta el valor de milisegundos más cercano. Para mediciones de mayor precisión, use las Elapsed propiedades o ElapsedTicks .
Puede consultar las propiedades Elapsed, ElapsedMillisecondsy ElapsedTicks mientras la Stopwatch instancia se está ejecutando o detenida. Las propiedades de tiempo transcurrido aumentan constantemente mientras Stopwatch se ejecuta ; permanecen constantes cuando se detiene la instancia.
De forma predeterminada, el valor de tiempo transcurrido de una Stopwatch instancia es igual al total de todos los intervalos de tiempo medidos. Cada llamada a comienza a Start contar en el tiempo acumulado transcurrido; cada llamada a Stop finaliza la medición del intervalo actual e inmoviliza el valor de tiempo transcurrido acumulado. Use el Reset método para borrar el tiempo transcurrido acumulado en una instancia existente Stopwatch .