silverlight popup control issue

Question

Hello everyone,

I am using VSTS 2008 + Silverlight 3 with Silverlight Popup control. I am confused about the VerticalOffset property.

From MSDN, it is mentioned,

"Gets or sets the vertical distance between the target origin and the popup alignment point. This is a dependency property."

http://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.popup.verticaloffset.aspx

My confusion is what means "between the target origin and the popup alignment point"? Especially what means "target origin" and "popup alignment point"?

thanks in advance, George

Answer 1

TargetOrigin is some sort of origin (0,0) of your control which is usually at Left,Top of control where else VerticalOffset is Vertical Transformation with respect to this point.

In WPF, transformations are useful for animation, for example if you have an object at (100,100), to move it up and down you will have to give coordinates (100,90) , (100,110) in animation, but to make it very effective, we do animation via transformation by changing VerticalOffset property.

The origin remains same, the position of an object remains same but offsets provide transformations changes it visual appearance.

WPF have more such properties, move, rotate, scale, all are used for animation with respect to the original position.