I implemented the IEnumerator interface in some classes to enable the use of the foreach statement. As you probalbly know, the interface asks for the implementation of
object IEnumerator.Cur ren
bool IEnumerator.Mov eNext() an
void IEnumerator.Res et()
The help to IEnumerator.Mov eNext describes that "after the end of the collection is passed, subsequent calls to MoverNect return false until reset is called"
When, however, I have two foreach() loops after another in one method, the Reset() interface is gets called. Thus the second loop never returns an element!!
Can anybody tell me why? Is this the 'normal' implementation
Thanx for any help
Han
in code
foreach(CEntry Entry in MyObject
// do stuf
...
.... // Other operations, NOT MODIFYING MyObject !!
...
foreach(CEntry Entry in MyObject) // MyObject NEVER returns an objec
// do stuf 3 7098
Hans,
I think that you meant to say that it doesn't get called.
When you return the enumerator from the implementation of IEnumerable,
are you passing back the same enumerator? If you are, then you have to
manually call the Reset method when the same instance is returned.
Otherwise, if you use a different implementation of IEnumerator each time,
you should not have a problem.
If you could provide a code sample, that would help (specifically, the
implementation of the enumerator and the IEnumerable interface).
Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard. caspershouse.co m
"Hans" <an*******@disc ussions.microso ft.com> wrote in message
news:9C******** *************** ***********@mic rosoft.com... I implemented the IEnumerator interface in some classes to enable the use
of the foreach statement. As you probalbly know, the interface asks for the
implementation of object IEnumerator.Cur rent bool IEnumerator.Mov eNext() and void IEnumerator.Res et().
The help to IEnumerator.Mov eNext describes that "after the end of the
collection is passed, subsequent calls to MoverNect return false until reset
is called". When, however, I have two foreach() loops after another in one method, the
Reset() interface is gets called. Thus the second loop never returns an
element!!! Can anybody tell me why? Is this the 'normal' implementation?
Thanx for any help, Hans
in code:
foreach(CEntry Entry in MyObject) { // do stuff } ... ... // Other operations, NOT MODIFYING MyObject !!! ... foreach(CEntry Entry in MyObject) // MyObject NEVER returns an object { // do stuff }
Hans,
I think that you meant to say that it doesn't get called.
When you return the enumerator from the implementation of IEnumerable,
are you passing back the same enumerator? If you are, then you have to
manually call the Reset method when the same instance is returned.
Otherwise, if you use a different implementation of IEnumerator each time,
you should not have a problem.
If you could provide a code sample, that would help (specifically, the
implementation of the enumerator and the IEnumerable interface).
Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard. caspershouse.co m
"Hans" <an*******@disc ussions.microso ft.com> wrote in message
news:9C******** *************** ***********@mic rosoft.com... I implemented the IEnumerator interface in some classes to enable the use
of the foreach statement. As you probalbly know, the interface asks for the
implementation of object IEnumerator.Cur rent bool IEnumerator.Mov eNext() and void IEnumerator.Res et().
The help to IEnumerator.Mov eNext describes that "after the end of the
collection is passed, subsequent calls to MoverNect return false until reset
is called". When, however, I have two foreach() loops after another in one method, the
Reset() interface is gets called. Thus the second loop never returns an
element!!! Can anybody tell me why? Is this the 'normal' implementation?
Thanx for any help, Hans
in code:
foreach(CEntry Entry in MyObject) { // do stuff } ... ... // Other operations, NOT MODIFYING MyObject !!! ... foreach(CEntry Entry in MyObject) // MyObject NEVER returns an object { // do stuff }
Hans wrote: I figured it out myself: I implemented the IEnumerator directly in my class, which limits the number of concurrend enumeration processes to ONE. Now I have a seperate enumerator class that implements IEnumerator. The class is instantiated by calling the IEnumerator.Get Enumerator() interface, implemented in my class.
It's ok to implement the enumerator directly in your class, if you know
that you'll never need to have two open enumerators for the same object.
The only thing you need to do to fix your original problem is to
forcibly call your Reset() method from within GetEnumerator() (or just
do the same steps your Reset() method does). This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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I implemented the IEnumerator interface in some classes to enable the use of the foreach statement. As you probalbly know, the interface asks for the implementation of
object IEnumerator.Curren
bool IEnumerator.MoveNext() an
void IEnumerator.Reset()
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