WPF Scrollviewer和ScrollChanged事件

Question

My task is to create scrollviewer with images. At first I dont want to load them all. I want to load 50 images and when the scroll slider is about half then load another 50 pictures and so on.

My start point:

        if (MyContent.VerticalOffset == MyContent.ScrollableHeight / 2 && MyContent.VerticalOffset != 0)
        {
            MessageBox.Show("Half");
        }

First problem is When i slide too fast, event doesn't fire. Maybe have already some solution for this task.

Answer 1

You're only checking if VerticalOffset is equal to ScrollableHeight . User can avoid this one single spot by moving the scroll bar very fast. Events are not fired that frequent, so you should check if VerticalOffset is past half. You can achieve this by changing operator from == to >= :

if (MyContent.VerticalOffset >= MyContent.ScrollableHeight / 2 && MyContent.VerticalOffset != 0)
{
    MessageBox.Show("Past Half");
}