【正文】 文件，或者將其作為獨立的應(yīng)用程序進行播放。 游戲 許多游戲都是使用 Flash 構(gòu)建的。 靈活消息區(qū)域 設(shè)計人員使用 web 頁中的這些區(qū)域顯示可能會不斷變化的信息。 要構(gòu)建 Flash 應(yīng)用程序，通常需要執(zhí)行下列基本步驟： 1. 確定應(yīng)用程序要執(zhí)行哪些基本任務(wù)。 5. 編寫 ActionScript 代碼以控制媒體元素的行為方式，包括這些元素對用戶交互的響應(yīng)方式。 根據(jù)您的項目和工作方式，您可以按不同的順序使用上述步驟。用戶單擊鼠標(biāo)按鈕或按鍵；在滿足特定條件或進程完成（ SWF 文件加載、時間軸到達特定的幀、圖形完成下載3 等）時，系統(tǒng)會觸發(fā)相關(guān)事件。 鼠標(biāo)和鍵盤事件 用戶與 SWF 文件或應(yīng)用程序交互時觸發(fā)鼠標(biāo)和鍵盤事件。例如，可以在用戶進入場景時將外部 SWF 文件或 JPG 圖像加載到影片剪輯中，或允許用戶使用移動鼠標(biāo)的方法在場景中調(diào)整元素的位置。附加到幀上的腳本稱為 幀腳本 。 將 SWF 文件停止在特定的關(guān)鍵幀后，您需要執(zhí)行某種動作。另外，這還會導(dǎo)致難于在不同的 Flash 應(yīng)用程序之間共享代碼。常見的做法是創(chuàng)建一個名為 動作 的圖層，并將 ActionScript 代碼放置在 該圖層上。隨著項目的擴展，這種簡便性帶來的好處將超出您的想像。還可以使用組件（預(yù)構(gòu)建的影片剪輯）共享代碼和功能，例如 UI 元素和腳本。是使用 動作 面板還是 腳本 窗口取決于您如何響應(yīng)事件、如何組織代碼，而最重要的是，取決于編碼最佳做法的要求。 您應(yīng)該轉(zhuǎn)而通過調(diào)用駐留在一個中心位置的函數(shù)來響應(yīng)事件 。 動作 面板和 腳本 窗口都具有 腳本 窗格（在其中鍵入代碼）和 動作 工具箱。 the system triggers events when specific conditions are met or processes pleted (the movie loads, the Timeline reaches a certain frame, a graphic finishes downloading, and so on). When an event occurs, you write an event handler to respond to the event with an action. Understanding when and where events occur will help you to determine how and where you will respond to the event with an action, and which ActionScript tools should be used in each case. Events can be grouped into a number of categories: mouse and keyboard events, which occur when a user interacts with your Flash application via the mouse and keyboard。 if a key on the keyboard is pressed, the on (keyPress) event occurs. You can attach scripts to handle these events and add all the interactivity you desire. Clip events Within a movie clip, you may react to a number of clip events that are triggered when the user enters or exits the scene or interacts with the scene using the mouse or keyboard. You might, for example, load an external SWF file or JPG image into the movie clip when the user enters the scene, or allow the user’s mouse movements to reposition elements in the scene. Frame events On a main or movie clip Timeline, a system event occurs when the playhead enters a keyframe— this is known as a frame event. Frame events are useful for triggering actions based on the passage of time (moving through the Timeline) or for interacting with elements that are currently visible on the stage. When you add a script to a keyframe, it is executed when the keyframe is reached during playback. A script attached to a frame is called a frame script. One of the most mon uses of frame scripts is to stop the playback when a certain keyframe is reached. This is done with the stop() function. You select a keyframe and then add the stop() function as a script element in the Actions panel. Once you’ve sto pped the movie at a certain keyframe, you need to take some action. You could, for example, use a frame script to dynamically update the value of a label, to manage the interaction of elements on the stage, and so on. For more information, see Chapter 5, “ Handling Events,” on page . Organizing ActionScript code You may attach scripts to keyframes and to object instances (movie clips, buttons, and other symbols). However, if your ActionScript code is scattered over many keyframes and object instances, debugging your application will be much more difficult. It will also be impossible to share your code between different Flash applications. Therefore, it’s important to follow best practices for coding when you create ActionScript in Flash. 10 Rather than