網站中運用Flash技術的優點和缺點_Flash教程

推薦：新手來看：Flahs as入門教程
這里我只簡單的介紹一下AS的基本常識。首先我們要了解AS要寫在什么地方，什么時候AS會被觸發執行。1、幀：寫在要害幀上面的AS，當時間軸上的指針走到這個要

Flash is a powerful web technology that achieves a high level of visual impact from the graphical point of view. Unfortunately, it is widely misused in web design. There are still many problems with Flash, especially related to usability and search engine behaviour; we need to thoroughly understand what those problems are before we decide to use Flash for our site.

Flash是一種功能強大的網站設計技術，從繪圖學觀點來說，Flash確實能產生高水平的視覺影響力。然而，很多網站亂用Flash技術，致使網站出現某些運行問題。在可用性以及與搜索引擎的關系方面，Flash仍然存在自身的缺點，所以在運用Flash以前，我們需要首先了解它可能引發的幾個問題。

As with any business decision, it all boils down to understanding what our target audience wants.

在做任何業務決策之前，都必須考慮目標客戶的需要。

If you want to make a big impression from a graphical point of view, Flash is definitely a good approach. However, concrete evidence still points to the fact that most web users utilize the web to find information, and what they regard most important is:

從繪圖學觀點來說，假如希望網站給客戶留下深刻的印象，使用Flash就是一種好方法。然而，很多實事證實：大部分用戶只是利用網站搜索信息，它們認為網站最重要的是：

a) quality of content

內容質量

b) ease of navigation, and

簡便的導航系統，以及

c) speed.

下載速度

Users also consider the web a highly interactive medium: they are unlikely to watch a computer screen for long periods of time without giving some sort of input.

同時，用戶認為網絡是一種互動媒體：他們不會長時間瀏覽電腦屏幕，肯定要輸入相關內容。

Flash technology presents several problems that go against the way most people use the web. For example:

Flash技術會引發幾個問題，在網站運行中，會給大多數用戶帶來麻煩。

 Bandwidth and Load Time Constrains: Sites designed with Flash take a long time to download and consume vast amounts of bandwidth. Not all users have a broadband connection. Flash forces users with dial-up connections to spend valuable time watching the load bar, instead of getting to the information they want, fast.

帶寬與下載時間的限制：用Flash技術設計的網站，占用大量的寬帶空間，下載速度很慢。一定記住：并不是所有用戶都利用寬帶上網。在登錄Flash網站時，電話撥號上網的用戶必須花費寶貴時間觀看下載條，而不能快速獲取需要的信息。

 Usability Constrains: When you navigate a Flash site designed with a older version, the back button does not work: instead of taking you to the previous screen, it will get you out of the Flash site. Also, the standard colors for visited and unvisited links will not work, and users have no control over the text size they want to use.

可用性限制：用老版本Flash設計的網站，后退鍵沒有作用：點擊后退鍵會使你退出Flash網站，而不是返回上一層網頁。同時，鏈接以及非鏈接的標準顏色會發生改變，并且用戶須控制需要利用的文本尺寸。

 Furthermore, many times Flash sites go against the interactive nature of the web. Since Flash technology favors a "presentation style" approach that resembles television, users are many times reduced to mere observers that get bored after a while, no matter how good the graphics look.

而且，Flash 經常帶來網站交互問題。由于Flash支持類似于電視的呈現模式方法，所以用戶經常作為觀賞者出現。不管畫面多么精美，過一段時間，用戶就會對內容產生厭煩。

 Search Engine Constrains: Although large search engines like Google now have some Flash indexing capabilities, these are still very limited. You will definetely have a hard time achieving high rankings with a Flash site. One option around this problem is to design a second, search-engine-friendly HTML version of your site. This, though, usually represents an unnecessary expense in both time and money, since in most cases the HTML version alone will get the job done.

搜索引擎的限制：盡管像Google這樣的大型搜索引擎，現在具備了對Flash做索引的能力，但搜索內容仍然非常有限，所以Flash網站不會在搜索引擎中獲得好的排名。解決這個問題的一種方法是：利用HTML設計網站，這樣的網站會有一個好的排名。利用Flash設計網站，會增加不必要的金錢和時間開支，其實 HTML網頁就可以完成所有的功能。

Although few, there are some instances when Flash technology can actually be helpful:

盡管Flash存在以上幾個缺點，但它同樣有自己的優點：

a) When you need to show a presentation, for example a demo of your product.

可以運用Flash，展示內容，比如：展示公司樣品。

b) To develop interactive games, like those found on sites for kids like Sesame Street, Nickelodeum, or Yahoo! Games.

開發互動游戲時，可以運用Flash，比如：Sesame Street、 Nickelodeum, 、Yahoo! Games等兒童游戲，都使用了Flash

c) When you want to dress up a minimalist site. In this case, a small Flash animation or banner embedded in an HTML document will not consume excessive bandwidth, will load fast, and will enhance the appearance of a bare-bones site.

當你想裝飾簡約網站時，你可以運用小型Flash動畫，或者在HTML文件中插入標語性質的Flash，這樣不會占用過多的寬帶空間，下載速度很快，并且可以增加網站的觀賞性。

Although Macromedia (the company that developed Flash) is actively working to improve Flash's usability problems (they even formed a partnership with usability guru Jakob Nielsen in 2002), issues like slow downloads and search engine un-friendliness still remain a problem. Until these issues are addressed and solved, you will be better-off by only using Flash in those rare instances when it actually enhances the value of your content.

盡管，Macromedia（Flash開發公司）正在積極采取方法改善Flash的可用性問題（甚至在2002年組成以網站可用性研究專家Jakob Nielsen為首的工作組，專門研究這個問題），但是下載速度慢、搜索引擎對其不友好的問題，仍然沒有解決。在這些問題解決以后，假如利用Flash可以增加網站價值（少數情況），那你可以運用。

分享：Flash簡單制作光暈動畫效果
下面我們來做一個模擬光斑的效果，效果如上圖，這一課主要學習色彩的調節變換，因為調節出好的色彩才會使圖像更加亮麗，增加層次感和視覺效果。調出好的色彩誰