CollapsiblePanelExtender does not open fully on page load

Question

I am using CollapsiblePanelExtender from AjaxControlToolkit, it works fine when I click on it, but it will not expand fully on page load (increases by about 90%).

I need to collapse it and deploy it manually so that it fully opens.

I do not have the ExpandedSize property set because the contents of the panel are dynamic.

Any ideas?

Answer 1

Use the following style for the purpose of the expander:

.collapsiblePanelContainer { height: 0; overflow: hidden; } 

The CollapsiblePanelExtender takes care of the rest.

This tip is mentioned by Joe Stagner in the CollapsiblePanelExtender video.

Answer 2

If the data in the precast panels is fixed and there is no need to cause the page to postback, set the SuppressPostBack property to CollapsiblePanelExtender to true. This will speed up and speed up the expansion process. You will not notice the delay.

Answer 3

Try setting the "min-height" value in the style of the actual panel. Otherwise, you can programmatically set the height or ExpandSize in the PreRender event

 protected override void OnPreRender(EventArgs e) { base.OnPreRender(e); // Set the size here myCollapsiblePanelExtender.ExpandedSize = sizeValue; }