BreakpointTargetEnumerator 類別

Creates a BreakpointTargetEnumerator for the BreakpointTargets collection. This class cannot be inherited.

繼承階層

System.Object
  Microsoft.SqlServer.Dts.Runtime.DtsEnumerator
    Microsoft.SqlServer.Dts.Runtime.BreakpointTargetEnumerator

命名空間：  Microsoft.SqlServer.Dts.Runtime
組件：  Microsoft.SqlServer.ManagedDTS (在 Microsoft.SqlServer.ManagedDTS.dll 中)

語法

'宣告
Public NotInheritable Class BreakpointTargetEnumerator _
    Inherits DtsEnumerator
'用途
Dim instance As BreakpointTargetEnumerator

public sealed class BreakpointTargetEnumerator : DtsEnumerator

public ref class BreakpointTargetEnumerator sealed : public DtsEnumerator

[<SealedAttribute>]
type BreakpointTargetEnumerator =  
    class 
        inherit DtsEnumerator 
    end

public final class BreakpointTargetEnumerator extends DtsEnumerator

BreakpointTargetEnumerator 型別公開下列成員。

屬性

	名稱	說明
	Current	Gets the current BreakpointTarget object in the collection.

上層

方法

	名稱	說明
	Equals	(繼承自 Object。)
	GetHashCode	(繼承自 Object。)
	GetType	(繼承自 Object。)
	MoveNext	Advances the enumerator to the next element of the collection. (繼承自 DtsEnumerator。)
	Reset	Sets the enumerator to its initial position, which is before the first element in the collection. (繼承自 DtsEnumerator。)
	ToString	(繼承自 Object。)

上層

備註

Enumerators only enable reading the data in the collection. Enumerators cannot be used to modify the underlying collection.

Initially, the enumerator is positioned before the first element in the collection. The Reset method also brings the enumerator back to this position. At this position, calling the Current property throws an exception. Therefore, you must call MoveNext method to advance the enumerator to the first element of the collection before reading the value of Current.

Current returns the same object until either MoveNext or Reset is called. MoveNext sets Current to the next element.

After the end of the collection is passed, the enumerator is positioned after the last element in the collection, and calling MoveNext returns false. If the last call to MoveNext returned false, calling Current throws an exception. To set Current to the first element of the collection again, you can call Reset followed by MoveNext.

An enumerator remains valid as long as the collection remains unchanged. If changes are made to the collection, such as adding, modifying, or deleting elements, the enumerator is invalidated and becomes irrecoverable; thus the next call to MoveNext or Reset throws an InvalidOperationException. However, if the collection is modified between MoveNext and Current, Current will return the element that it is set to, even if the enumerator has been invalidated.

The enumerator does not have exclusive access to the collection; therefore, enumerating through a collection is not a thread-safe procedure. Even when a collection is synchronized, other threads could still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

執行緒安全性

這個型別的任何公用 static (在 Visual Basic 中為 Shared) 成員都是執行緒安全的。並不是所有的執行個體成員都保證可以用於所有的執行緒。

請參閱

參考

Microsoft.SqlServer.Dts.Runtime 命名空間