Stopwatch.ElapsedMilliseconds Property
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Gets the total elapsed time measured by the current instance, in milliseconds.
public:
property long ElapsedMilliseconds { long get(); };public long ElapsedMilliseconds { get; }member this.ElapsedMilliseconds : int64Public ReadOnly Property ElapsedMilliseconds As LongProperty Value
A read-only long integer representing the total number of milliseconds measured by the current instance.
Examples
The following example uses the Stopwatch class to measure the performance of four different implementations for parsing an integer from a string. This code example is part of a larger example provided for the Stopwatch class.
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
Remarks
This property represents elapsed time rounded down to the nearest whole millisecond value. For higher precision measurements, use the Elapsed or ElapsedTicks properties.
You can query the properties Elapsed, ElapsedMilliseconds, and ElapsedTicks while the Stopwatch instance is running or stopped. The elapsed time properties steadily increase while the Stopwatch is running; they remain constant when the instance is stopped.
By default, the elapsed time value of a Stopwatch instance equals the total of all measured time intervals. Each call to Start begins counting at the cumulative elapsed time; each call to Stop ends the current interval measurement and freezes the cumulative elapsed time value. Use the Reset method to clear the cumulative elapsed time in an existing Stopwatch instance.
