Hello Tony!

Thank you for your response!

I'll try to discribe my problem in a different way:
I made my own class:
Class MyEnumerator
Implements IEnumerator

the Public ReadOnly Property Current() - methode is called by the grid for every row. Don't mather if the row is needed or not.
Unfortunately ther's no method like "getUpperBound" in IEnumerator so the only way is "MoveNext()" 'til false is returned. But the call of "Current()" for undisplayed rows is unneeded.

regards, Philipp

I forgot: I have to use the virtual XMLLoadOnDemandType

 I was able to succefully implement this kind of binding by modifying the MoveNext function in order to Skip top currentRowCount  enumeration and enumerate only the DataPortionSize rows needed for the partial binding

Like this

            /// <summary>
            /// MOVE NEXT
            /// </summary>
            /// <returns></returns>
            public bool MoveNext()
            {
                moveNextCount++;
                               
                //Skip Rows
                bool _success = false;
                while (currentRowCount > 0)
                {
                    currentRowCount--;
                    _success = respondentEnumerator.MoveNext();
                    if (_success == false)
                        break;
                }


                _success = respondentEnumerator.MoveNext();
                if ( _success )
                {
                    currentRowCount = 0;
                    string _key = (string)respondentEnumerator.Current;
                    Respondent _resp = viewManager.respondentCentral.Respondents[_key];
                    current = new ViewOpenEndBrowser(_resp, additionalInfo);
                }

                //Check if we have to stop the enumeration
                if (viewManager.DataPortionSize > 0 && getCurrentCount > viewManager.DataPortionSize)
                {
                    //Get Current limits reach
                    //Reset Counter
                    getCurrentCount = 0;
                   
                    //Stop the enumaration
                    return false;
                }

                return _success;
               
            }
 

Philipp,

The grid has no way of guessing what behavior you want it to provide with your enumerator.  It cannot know where to start off or where to stop because it's an enumerator, nor can it assume that it should just start reading from the current spot.  It treats the enumerator as a collection of values which it must display.  It will enumerate through every value and then determine which values are necessary to fill the current request. 

Because of this, you need to help the grid understand exactly what you need by using the initializedatasource method as described above.  By telling the grid that you are supporting partialdatabinding and providing it with the next N rows, you can ensure that it doesn't loop through unnecessary rows in your datasource.

Hope this helps,

-Tony