I have a situation that has me absolutely perplexed.

I'm still using UltraWebGrid 10.2. I recently learned that the performance associated with this grid becomes unacceptable when the number of records in the grid approaches 100. I have a DropDownList column in the grid that provides the names of our employees when a cell in that column is clicked. The end user then selects from the list and the employee name is placed in the cell.

I've been doing some testing this morning and learned that a significant bottleneck occurs in the CellClickHandler for this drop-down grid column. The incredible thing (to me) is that it only occurs the FIRST TIME one of these cells is clicked! I have a JavaScript loop (MyGrid.Rows.length = 25) that looks like this inside this handler:

for (i=0;i<MyGrid.Rows.length;i++) {

--- Do Stuff ---

}

I capture the system time before entering the loop and again after the loop completes. For only 25 grid records, it takes appx. 4 seconds to execute the loop the FIRST TIME THROUGH! As more records are added to the grid, the response time increases geometrically. However, after the drop-down appears and I click another cell in the column, the same loop executes in only a few milliseconds.

When I first enter this loop, the logic recognizes that there are 25 records in the grid. I can't for the life of me understand why the huge performance difference after clicking a cell the first time. Can someone suggest why the performance is so bad the first time I click a cell in the column, but seems to clear up for subsequent clicks?