IDTSRuntimeConnectionCollection100.GetEnumerator Method
Definition
Important
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Returns an enumerator that can iterate through an IDTSRuntimeConnectionCollection100.
public:
System::Collections::IEnumerator ^ GetEnumerator();
[System.Runtime.InteropServices.DispId(-4)]
public System.Collections.IEnumerator GetEnumerator ();
[<System.Runtime.InteropServices.DispId(-4)>]
abstract member GetEnumerator : unit -> System.Collections.IEnumerator
Public Function GetEnumerator () As IEnumerator
Returns
An enumerator that can iterate through an IDTSRuntimeConnectionCollection100.
Implements
- Attributes
Remarks
Enumerators only allow 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. Reset
also brings the enumerator back to this position. At this position, calling Current
throws an exception. Therefore, you must call MoveNext
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 irrecoverably invalidated and the next call to MoveNext
or Reset
throws an InvalidOperationException
. If the collection is modified between MoveNext
and Current
, Current
returns the element that it is set to, even if the enumerator is already invalidated.
The enumerator does not have exclusive access to the collection; therefore, enumerating through a collection is intrinsically not a thread-safe procedure. Even when a collection is synchronized, other threads can 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.