Get icon name.
The difference from icon property is that this function provides default icon name if no explicitly set.
The default form is MIME type name with '/' replaces with '-'.
Note: This function will allocate every time it's called if no icon explicitly set.
Get icon name. The difference from icon property is that this function provides default icon name if no explicitly set. The default form is MIME type name with '/' replaces with '-'. Note: This function will allocate every time it's called if no icon explicitly set.