Stopwatch.StartNew 方法

定義

命名空間:

System.Diagnostics

組件:

System.Runtime.dll

來源:

Stopwatch.cs

初始化新的 Stopwatch 執行個體，將已耗用時間屬性設定為零，然後開始測量已耗用時間。

C#

public static System.Diagnostics.Stopwatch StartNew ();

傳回

Stopwatch

剛開始測量已耗用時間的 Stopwatch。

範例

下列範例會 Stopwatch 使用 類別來測量四個不同實作的效能，以剖析字串中的整數。 此程式代碼範例是針對 類別提供的較大範例的 Stopwatch 一部分。

C#

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;
}

備註

這個方法相當於呼叫建 Stopwatch 構函式，然後在新的 實體上呼叫 Start 。

適用於

另請參閱

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