BreakpointTargetEnumerator Class
Definition
Important
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Creates a BreakpointTargetEnumerator for the BreakpointTargets collection. This class cannot be inherited.
public ref class BreakpointTargetEnumerator sealed : Microsoft::SqlServer::Dts::Runtime::DtsEnumerator
public sealed class BreakpointTargetEnumerator : Microsoft.SqlServer.Dts.Runtime.DtsEnumerator
type BreakpointTargetEnumerator = class
inherit DtsEnumerator
Public NotInheritable Class BreakpointTargetEnumerator
Inherits DtsEnumerator
- Inheritance
Remarks
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.
Properties
Current |
Gets the current BreakpointTarget object in the collection. |
Methods
MoveNext() |
Advances the enumerator to the next element of the collection. (Inherited from DtsEnumerator) |
Reset() |
Sets the enumerator to its initial position, which is before the first element in the collection. (Inherited from DtsEnumerator) |