<StackPanel>
<Grid>
// A List of Images
</Grid>
<Panel>
// A button
<Clicked Handler="AddImagesToList"/>
</Panel>
I did something like this. When I pressed the button, the list of images would be added more images. And supposed that the height of list would increase and the button would move to the bottom. However, sometimes the button move to an incorrect position. And I think it should be the reason that the Grid could not update the correct height of the image list.
After I change the Grid to dockpanel, it seems work normally.