Thank you for your detailed explication.
Not to mention the timer, I agree with you that the expanded state and the vertical scrollbar are being adjusted during the gridview updates.
But, there is one thing that I don't understand. The gridiew doesn't flick between several updates without scrolling.The gridiew flicks if I scroll then update the gridview only for the first time.
What's the difference between these 2 cases ?
1. load the gridview (all expanded) -> update -> update -> update .....: the gridview is always stable
2. load the gridview (all expanded) -> scroll -> (I can wait long enough to make sure the gridview doesn't move) -> update -> the gridview flicks ->update ->the gridview is stable.: the grid flicks only at first update after the scrolling.
It is the same content and the same data that I've updated for the 2 updates. Why the grid flicks only at the first time?
And also, if I scrolls upwards then updates, the displayed view won't change but the scrolling bar will flick.(it's acceptable for me.)
If I scrolls downwards then updates, the displayed view and the scrolling bar will both flick.
In my opinion, some value maybe isn't saved well at the end of the scrolling. After the first update, some value is lost, it causes the movement.
Thank you by advance.