Stopwatch.StartNew Metodo

Definizione

Spazio dei nomi:

System.Diagnostics

Assembly:

System.Runtime.dll

Origine:

Stopwatch.cs

Inizializza una nuova istanza di Stopwatch, imposta su zero la proprietà relativa al tempo trascorso e avvia la misurazione del tempo trascorso.

public:
 static System::Diagnostics::Stopwatch ^ StartNew();

public static System.Diagnostics.Stopwatch StartNew ();

static member StartNew : unit -> System.Diagnostics.Stopwatch

Public Shared Function StartNew () As Stopwatch

Restituisce

Stopwatch

Oggetto Stopwatch che ha appena iniziato a misurare il tempo trascorso.

Esempio

Nell'esempio seguente viene usata la Stopwatch classe per misurare le prestazioni di quattro implementazioni diverse per l'analisi di un numero intero da una stringa. Questo esempio di codice fa parte di un esempio più ampio fornito per la Stopwatch classe .

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;
}

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;
}

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

Commenti

Questo metodo equivale a chiamare il Stopwatch costruttore e quindi a chiamare Start sulla nuova istanza.

Vedi anche

• Start()
• Stop()
• IsRunning
• Reset()