引發並在自訂工作中定義事件

Integration Services 執行階段引擎提供事件的集合，可以顯示驗證與執行工作時的工作進度狀態。 IDTSComponentEvents 介面會定義這些事件，而且是以 Validate 和 Execute 方法的參數提供給工作。

另一組定義在 IDTSEvents 介面的事件，是由 TaskHost 代表工作而引發。 TaskHost 會引發在驗證和執行前後發生的事件，而工作會引發在執行和驗證期間發生的事件。

建立自訂事件

自訂工作開發人員可以透過在 InitializeTask 方法的覆寫實作中建立新的 EventInfo，以定義新自訂事件。 在建立 EventInfo 之後，會使用 Add 方法，將它加入 EventInfos 集合。 Add 方法的方法簽章如下所示：

public void Add(string eventName, string description, bool allowEventHandlers, string[] parameterNames, TypeCode[] parameterTypes, string[] parameterDescriptions);

下列程式碼範例會示範自訂工作的 InitializeTask 方法，其中建立了兩個自訂事件並設定其屬性。 然後會將新事件加入 EventInfos 集合。

第一個自訂事件的 eventName 為 "OnBeforeIncrement"，而 description 為「更新初始值之後觸發」。下一個參數 true 值表示此事件應允許建立事件處理常式容器以處理事件。 事件處理常式是提供封裝中結構與工作服務的容器，就像封裝、時序、ForLoop 和 ForEachLoop 等其他容器一樣。 當 allowEventHandlers 參數是 true 時，會為事件建立 DtsEventHandler 物件。 為事件定義的任何參數現在可供 DtsEventHandler 的變數集合中之 DtsEventHandler 使用。

public override void InitializeTask(Connections connections,
   VariableDispenser variables, IDTSInfoEvents events,
   IDTSLogging log, EventInfos eventInfos,
   LogEntryInfos logEntryInfos, ObjectReferenceTracker refTracker)
{
    this.eventInfos = eventInfos;
    string[] paramNames = new string[1];
    TypeCode[] paramTypes = new TypeCode[1]{TypeCode.Int32};
    string[] paramDescriptions = new string[1];

    paramNames[0] = "InitialValue";
    paramDescriptions[0] = "The value before it is incremented.";

    this.eventInfos.Add("OnBeforeIncrement", 
      "Fires before the task increments the value.",
      true,paramNames,paramTypes,paramDescriptions);
    this.onBeforeIncrement = this.eventInfos["OnBeforeIncrement"];

    paramDescriptions[0] = "The value after it has been incremented.";
    this.eventInfos.Add("OnAfterIncrement",
      "Fires after the initial value is updated.",
      true,paramNames, paramTypes,paramDescriptions);
    this.onAfterIncrement = this.eventInfos["OnAfterIncrement"];
}

Public Overrides Sub InitializeTask(ByVal connections As Connections, _
ByVal variables As VariableDispenser, ByVal events As IDTSInfoEvents, _
ByVal log As IDTSLogging, ByVal eventInfos As EventInfos, _
ByVal logEntryInfos As LogEntryInfos, ByVal refTracker As ObjectReferenceTracker) 

    Dim paramNames(0) As String
    Dim paramTypes(0) As TypeCode = {TypeCode.Int32}
    Dim paramDescriptions(0) As String

    Me.eventInfos = eventInfos

    paramNames(0) = "InitialValue"
    paramDescriptions(0) = "The value before it is incremented."

    Me.eventInfos.Add("OnBeforeIncrement", _
      "Fires before the task increments the value.", _
      True, paramNames, paramTypes, paramDescriptions)
    Me.onBeforeIncrement = Me.eventInfos("OnBeforeIncrement")

    paramDescriptions(0) = "The value after it has been incremented."
    Me.eventInfos.Add("OnAfterIncrement", _
      "Fires after the initial value is updated.", True, _
      paramNames, paramTypes, paramDescriptions)
    Me.onAfterIncrement = Me.eventInfos("OnAfterIncrement")

End Sub

引發自訂事件

自訂事件是透過呼叫 FireCustomEvent 方法來引發。 下列程式碼行會引發自訂事件。

componentEvents.FireCustomEvent(this.onBeforeIncrement.Name,
   this.onBeforeIncrement.Description, ref arguments,
   null, ref bFireOnBeforeIncrement);

componentEvents.FireCustomEvent(Me.onBeforeIncrement.Name, _
Me.onBeforeIncrement.Description, arguments, _
Nothing,  bFireOnBeforeIncrement)

範例

下列範例顯示的工作會在 InitializeTask 方法中定義自訂事件，將自訂事件加入 EventInfos 集合，然後透過呼叫 FireCustomEvent 方法在其 Execute 方法期間引發自訂事件。

[DtsTask(DisplayName = "CustomEventTask")]
    public class CustomEventTask : Task
    {
        public override DTSExecResult Execute(Connections connections, 
          VariableDispenser variableDispenser, IDTSComponentEvents componentEvents,
           IDTSLogging log, object transaction)
        {
            bool fireAgain;
            object[] args = new object[1] { "The value of the parameter." };
            componentEvents.FireCustomEvent( "MyCustomEvent", 
              "Firing the custom event.", ref args,
              "CustomEventTask" , ref fireAgain );
            return DTSExecResult.Success;
        }

        public override void InitializeTask(Connections connections,
          VariableDispenser variableDispenser, IDTSInfoEvents events,
          IDTSLogging log, EventInfos eventInfos,
          LogEntryInfos logEntryInfos, ObjectReferenceTracker refTracker)
        {
            string[] names = new string[1] {"Parameter1"};
            TypeCode[] types = new TypeCode[1] {TypeCode.String};
            string[] descriptions = new string[1] {"Parameter description." };

            eventInfos.Add("MyCustomEvent",
             "Fires when my interesting event happens.",
             true, names, types, descriptions);

        }
   }

<DtsTask(DisplayName = "CustomEventTask")> _ 
    Public Class CustomEventTask
     Inherits Task
        Public Overrides Function Execute(ByVal connections As Connections, _
          ByVal variableDispenser As VariableDispenser, _
          ByVal componentEvents As IDTSComponentEvents, _
          ByVal log As IDTSLogging, ByVal transaction As Object) _
          As DTSExecResult

            Dim fireAgain As Boolean
            Dim args() As Object =  New Object(1) {"The value of the parameter."}

            componentEvents.FireCustomEvent("MyCustomEvent", _
              "Firing the custom event.", args, _
              "CustomEventTask" ,  fireAgain)
            Return DTSExecResult.Success
        End Function
 
        Public Overrides  Sub InitializeTask(ByVal connections As Connections, _
          ByVal variableDispenser As VariableDispenser,
          ByVal events As IDTSInfoEvents,
          ByVal log As IDTSLogging, ByVal eventInfos As EventInfos, ByVal logEnTryInfos As LogEnTryInfos, ByVal refTracker As ObjectReferenceTracker)

            Dim names() As String =  New String(1) {"Parameter1"}
            Dim types() As TypeCode =  New TypeCode(1) {TypeCode.String}
            Dim descriptions() As String =  New String(1) {"Parameter description."}

            eventInfos.Add("MyCustomEvent", _
              "Fires when my interesting event happens.", _
              True, names, types, descriptions)

        End Sub

    End Class

請參閱

工作

將事件處理常式加入封裝中

概念

Integration Services (SSIS) 事件處理常式