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InstanceDataCollection.Item[String] 屬性

定義

取得與這個計數器相關聯的執行個體資料。 通常是一組未經處理的計數器值。

public:
 property System::Diagnostics::InstanceData ^ default[System::String ^] { System::Diagnostics::InstanceData ^ get(System::String ^ instanceName); };
public System.Diagnostics.InstanceData this[string instanceName] { get; }
member this.Item(string) : System.Diagnostics.InstanceData
Default Public ReadOnly Property Item(instanceName As String) As InstanceData

參數

instanceName
String

效能計數器分類執行個體的名稱,如果分類包含單一執行個體,則為空字串 ("")。

屬性值

InstanceData 項目,InstanceDataCollection 物件要根據它來建立索引。

例外狀況

instanceName 參數為 null

範例

下列程式代碼範例會接受 PerformanceCounter 命令行中的類別名稱、計數器名稱和實例名稱。 它會取得 InstanceDataCollectionCollection 類別的 InstanceDataCollection ,這是物件的集合。 其會從中取得指定計數器的特定 InstanceDataCollection 。 然後,如果實例存在,此範例會 Item[] 使用屬性 (做為索引器) 來取得相關聯的 InstanceData 物件。

public static void Main(string[] args)
{
    // These values can be used as arguments.
    string categoryName = "Process";
    string counterName = "Private Bytes";
    string instanceName = "Explorer";

    InstanceDataCollection idCol;
    const string SINGLE_INSTANCE_NAME = "systemdiagnosticsperfcounterlibsingleinstance";

    // Copy the supplied arguments into the local variables.
    try
    {
        categoryName = args[0];
        counterName = args[1];
        instanceName = args[2];
    }
    catch
    {
        // Ignore the exception from non-supplied arguments.
    }

    try
    {
        // Get the InstanceDataCollectionCollection for this category.
        PerformanceCounterCategory pcc = new PerformanceCounterCategory(categoryName);
        InstanceDataCollectionCollection idColCol = pcc.ReadCategory();

        // Get the InstanceDataCollection for this counter.
        idCol = idColCol[counterName];
        if (idCol==null)
        {
            throw new Exception("Counter does not exist.");
        }
    }
    catch(Exception ex)
    {
        Console.WriteLine("An error occurred getting the InstanceDataCollection for " +
            "category \"{0}\", counter \"{1}\"." +  "\n" + ex.Message, categoryName, counterName);
        return;
    }

    // If the instance name is empty, use the single-instance name.
    if (instanceName.Length==0)
    {
        instanceName = SINGLE_INSTANCE_NAME;
    }

    // Check if this instance name exists using the Contains
    // method of the InstanceDataCollection.
    if (!idCol.Contains(instanceName))
    {
        Console.WriteLine("Instance \"{0}\" does not exist in counter \"{1}\", " +
            "category \"{2}\".", instanceName, counterName, categoryName);
        return;
    }
    else
    {
        // The instance name exists, now get its InstanceData object
        // using the indexer (Item property) for the InstanceDataCollection.
        InstanceData instData = idCol[instanceName];

        Console.WriteLine("CategoryName: {0}", categoryName);
        Console.WriteLine("CounterName:  {0}", counterName);
        Console.WriteLine("InstanceName: {0}", instData.InstanceName);
        Console.WriteLine("RawValue:     {0}", instData.RawValue);
    }
}
Sub Main(ByVal args() As String)
    ' These values can be used as arguments.
    Dim categoryName As String = "Process"
    Dim counterName As String = "Private Bytes"
    Dim instanceName As String = "Explorer"

    Dim idCol As InstanceDataCollection
    Const SINGLE_INSTANCE_NAME As String = _
        "systemdiagnosticsperfcounterlibsingleinstance"

    ' Copy the supplied arguments into the local variables.
    Try
        categoryName = args(0)
        counterName = args(1)
        instanceName = args(2)
    Catch ex As Exception
        ' Ignore the exception from non-supplied arguments.
    End Try

    Try
        ' Get the InstanceDataCollectionCollection for this category.
        Dim pcc As New PerformanceCounterCategory(categoryName)
        Dim idColCol As InstanceDataCollectionCollection = _
            pcc.ReadCategory()

        ' Get the InstanceDataCollection for this counter.
        idCol = idColCol(counterName)
        If idCol Is Nothing Then
            Throw New Exception("Counter does not exist.")
        End If
    Catch ex As Exception
        Console.WriteLine( _
            "An error occurred getting the InstanceDataCollection for " & _
            "category ""{0}"", counter ""{1}""." & vbCrLf & ex.Message, _
            categoryName, counterName)
        Return
    End Try

    ' If the instance name is empty, use the single-instance name.
    If instanceName.Length = 0 Then
        instanceName = SINGLE_INSTANCE_NAME
    End If

    ' Check if this instance name exists using the Contains
    ' method of the InstanceDataCollection.
    If Not idCol.Contains(instanceName) Then
        Console.WriteLine( _
            "Instance ""{0}"" does not exist in counter ""{1}"", " & _
            "category ""{2}"".", instanceName, counterName, categoryName)
        Return
    Else
        ' The instance name exists, now get its InstanceData object
        ' using the indexer (Item property) for the InstanceDataCollection.
        Dim instData As InstanceData = idCol(instanceName)

        Console.WriteLine("CategoryName: {0}", categoryName)
        Console.WriteLine("CounterName:  {0}", counterName)
        Console.WriteLine("InstanceName: {0}", instData.InstanceName)
        Console.WriteLine("RawValue:     {0}", instData.RawValue)
    End If
End Sub

備註

參數 instanceName 不區分大小寫。

適用於