How can I detect the Flash Asset Xtra in Shockwave?

The Flash Asset Xtra has been included with the default Shockwave download since February 1998, and is included in new computers that ship.

Developers usually use a front page that says "If you can't see the spinning animation, then you need to get the current Shockwave" with a link to the Macromedia site.

If you prefer to give them some other type of alert, then you can take advantage of how Director stores reserved keywords and symbols in a table. A comparison between symbols will actually compare numerical entry values in that table. The following function will return TRUE or FALSE depending on whether the Flash Asset Xtra is available:

on IsFlashXtraInstalled
if symbol("unique" & the ticks) > symbol("flash"] then ---此“]”为“）”。
return TRUE
else return FALSE
end


In this case, the phrase "symbol('unique' & the ticks)" will create a new symbol of format #unique1098347, eg. By coercing the string "flash" to a symbol we'll either create a new symbol (if Flash Xtra is not available), or refer to the previous symbol instance. The symbol comparison test will then return the correct value based on the order of these two symbols in the symbol lookup table.
原文如上，大意就是说那一小段文字可以检查是否flash xtra 可否用，可是这段程序我看不太懂，希望朋友们帮帮忙！更我解释一下吧，不胜感激！