Property Restart

Gets or sets the attribute that controls the circumstances under which an animation is restarted.

public string Restart { get; set; }

alwaysThe animation can be restarted at any time. This is the default value.
whenNotActive The animation can only be restarted when it is not active (i.e. after the active end). Attempts to restart the animation during its active duration are ignored.
never The element cannot be restarted for the remainder of the current simple duration of the parent time container. (In the case of SVG, since the parent time container is the SVG document fragment, then the animation cannot be restarted for the remainder of the document duration.)