Tài liệu Thiết kế flash với flash cs5 part 55 pdf

Say you create a button, and you want the ActionScript to trigger an instruction that will stop the movie, but only when the user clicks the button object.. What You’ll Do View the Actio

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Using Basic ActionScripts

Introduction

Flash's programming language is called ActionScript

ActionScript lets you create detailed instructions on how the

Flash movie will perform Flash CS5 allows you to build

applications using two different versions of ActionScript,

either ActionScript 1.0 & 2.0 or ActionScript 3.0

In this chapter, you’ll learn the basics of ActionScript

along with scripting as it relates to ActionScript 2.0 In the

next chapter, you’ll learn about scripting as it relates to

ActionScript 3.0 ActionScripts can use an event to trigger the

specific action Say you create a button, and you want the

ActionScript to trigger an instruction that will stop the movie,

but only when the user clicks the button object The defined

event is the user clicking his mouse, and the action would be

to stop playing the movie ActionScript is a relatively easy

language to learn, but a very precise language to code, so

pay close attention to the syntax

The good news is that once you master the language and

the syntax, the full power of Flash is available to you You can

create ActionScripts that are triggered (the event) by specific

data, or information typed in by a visitor You can even create

ActionScripts that are sensitive to variables such as date and

time Flash helps you by giving you functions (English-like

script) and as your ActionScript skills grow, you can even

cre-ate and call your own functions Each new version of Flash

moves the ActionScripting language closer and closer to

JavaScript The power of Flash is fully realized when you

write ActionScripts and incorporate them in your Flash

docu-ments

What You’ll Do

View the Actions Panel Set ActionScript Preferences Understand Properties and Methods Apply Properties and Methods to

an Object Use Dot Syntax Understand Data Types Use Functions

Use Conditional Statements Attach a Mouse Event to a Button Work with Frame Events

Work with Clip Events Attach a Clip Event to a Movie Clip Work with Loops

Use For Loops Work with ActionScript Behaviors

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The Actions panel is gives the Flash designer

control of a Flash document by allowing

him/her to create and edit actions for an

object or frame To use the Actions panel,

select an object on the stage, or select a

frame on the Timeline, click the Window

menu, and then click Actions Scripts can be

typed directly into the Actions panel using the

Script pane, or augmented by using a list of

installed Actions in the Toolbox

◆ Toolbox Supplies a list of all installed

actions, either ActionScript 1.0 & 2.0 or

ActionScript 3.0

◆ Script pane Enter the Actions into the

Script pane

◆ Script Navigator pane Gives reference

to all the Scripts in the active movie

◆ Current Script tag Indicates which

script is being edited

◆ Pin Script Adds a tab for a selected

script

◆ Options menu Contains options that

control and format the Actions panel

◆ Add Statement Lets you add script

elements to the current action

◆ Find, and Find and Replace Searches

the active script

◆ Insert Target Path Inserts a specific target clip into the action

◆ Check Syntax Checks the current action for syntax errors

◆ Auto Format Cleans up the script by auto indenting

◆ Auto Close Bracket When you type

an open bracket {, Flash automatically adds the corresponding close

bracket } (New !)

◆ Show Code Hint Gives you hints to the syntax of the action as you type

breakpoints into the action to pause

on the specified line of code

◆ Collapse and Expand Collapse between braces, collapse selection,

or expand all

◆ Comments Apply a block or line comment

◆ Code Snippet Code Snippets provides ActionScript 3.0 code segments to use in scripts (New !)

◆ Script Assist for 3.0 Script assist provides a visual interface for editing scripts (syntax completion and parameter descriptions)

◆ Help Provides online help

Viewing the Actions Panel

Script Tag

Script Navigator pane

Toolbox

Script pane

Help Script Assist Options menu

Pin Script Actions Panel toolbar buttons Code Snippets

Since ActionScripting is so important, Flash gives you the ability to con-trol the Actions panel through preferences ActionScript preferences give you the ability to control the font and size of the text typed into the Actions panel, as well as using syntax coloring to help you visualize the code You can also set AutoFormat preferences to specify the auto-matic formatting you want for your ActionScript code

Setting ActionScript

Preferences

Set ActionScript Preferences

Click the Flash (Mac) or Edit (Win)

menu, and then click Preferences.

Click the ActionScript category.

Select from the following options:

◆ Automatic Close Brace Select

to automatically insert a close

bracket (New !)

◆ Automatic Indentation.

Instructs Flash to perform

syntax indentation

◆ Tab Size Enter a value for the

number of spaces used

◆ Code Hints Gives you

on-screen hints as you type

◆ Delay Delay before showing a

code hint (0 to 4 seconds)

◆ Font Select a font and size for

the ActionScript text

◆ Open/Import and Save/Export

Select UTF-8 or Default

encoding for open and import

operations (UTF-8 is best)

◆ Reload Modified Files Click to

be prompted when Flash needs

to reload a modified file

◆ Class Editor Select an editor or

Ask to be prompted (New !)

◆ Syntax Coloring Choose the

syntax-coloring scheme

◆ Language Click ActionScript 2.0

or ActionScript 3.0 to modify the

ActionScript sub-settings

Click the Auto Format category.

Select format check boxes and

view the effect in preview

Click OK.

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To reset preference setting to the default, click Reset To Defaults.

Preview area

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Objects in Flash are defined using two primary identifiers: properties and methods The

proper-ties of an object define its characteristics In the real world, a house would be an object, and its

properties would be things like its color, style, and number of windows and doors In Flash, it

would be written something like this:

house.color = "green";

house.style = "ranch";

house.windows = "12";

house.doors = "2";

In this example, the word house is a unique instance name for the house object, and the words

color, style, windows, and doors represent the properties assigned to this instance Think of an

instance as a copy of a Library item When you create a movie clip, the object is created in

Flash's Library When you return to the Stage, you can then drag the movie clip from the

Library to the Stage (technically, you're moving a Library symbol, created using the movie clip

behavior) Once the movie clip is moved to the Stage, it is defined as an instance of the original

Library item When you select an instance on the Stage, Flash's Properties panel lets you give it

a unique name In the previous example, "house" is the unique name

Giving a Library symbol a unique name gives you a lot of control For example, you could

move two instances of the same movie clip onto the Stage, give each of them its own unique

name (house1, house2) in the Properties panel, and then define different properties for each

one Something like this:

house1.color = "green"; house2.color = "blue";

house1.style = "ranch"; house2.style = "tudor";

house1.windows = "12"; house2.windows = "8";

house1.doors = "2"; house2.doors = "4";

In Flash, most objects have properties For example, the MovieClip object has property

val-ues such as transparency, horizontal and vertical position, and visibility You might define

prop-erties loosely as the physical appearance of a movie clip, as it appears on the Flash Stage A

method instructs the object to perform some task A method is a function that is part of a class

definition For example, if a DVD player is an object, then the methods would be something

like: play, record, and stop Flash methods are written like this:

play();

record();

stop();

Some methods require parameters within the parenthesis The following method instructs the

play head to move to frame 6 on the Timeline and stop: gotoAndStop(6);

Attaching the method to a specific object requires identifying the object in the ActionScript

code: myDVD.gotoAndStop(6);

ActionScript is a language, and just like learning any foreign language, all the words and

syn-tax might seem strange at first; however, the longer you work with the language, the simpler it

becomes

Understanding Properties and Methods

Once you've gotten the hang of writing ActionScripts, the next step is

to apply properties and methods to objects in a Flash document You can have an object and let your visitor control its color Changing the color is an example of changing an object’s properties To make an object change color, you will need a Flash document that contains a MovieClip and button symbols An easy script translation would be:

Flash, when my visitor clicks (release) on the button, I want you to assign a new color to an object that I gave a unique instance name (change it), and I'm defining that property as objectColor, and change the color (setRGB) to red (0x990000) When you attach ActionScripts to buttons, you're not limited to just a single use For example, you could drag three instances of the same button symbol on the Stage and repeat the previous code with one exception: change the SetRGB value

of one to (0x990000) for red, another to (0x009900) for green, and the third one to (0x000099) for blue

Applying Properties

and Methods to an

Object

Apply Properties and Methods

Drag the movie clip onto the

Stage

Enter a unique instance name in

the Properties panel

Drag the button symbol onto the

Stage, and then select the symbol

Click the Window menu, and then

click Actions to open the Actions

panel

Enter the script (ActionScript 2.0)

as shown in the illustration

◆ ActionScript 3.0 example files

are available on the Web at

www.perspection.com

Click the Control menu, point to

Test Movie, and then click Test.

Click the button to change the

color of the object to red

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See Also

See “Creating Invisible Buttons” on

page 153 for information on creating

invisible buttons