ch01.txt

来自「ActionScript3.0 Cookbook范例源代码」· 文本 代码 · 共 983 行 · 第 1/2 页

    
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// Check if it is a weekend.
if ((current.getDay() == 0) || (current.getDay() == 6) ) {
  trace ("Why are you working on a weekend?");
}
    
    
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// Check to see if the name is not Bruce.
if (!(userName == "Bruce")) {
  trace ("This application knows only Bruce's birthday.");
}
    
    
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if (userName != "Bruce") {
  trace ("This application knows only Bruce's birthday.");
}
    
    
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// Check to see if a sprite is visible. If so, display a
// message. This condition is shorthand for _sprite.visible == true
if (_sprite.visible) {
  trace("The sprite is visible.");
}
    
    
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// Check to see if a sprite is invisible (not visible). If so, 
// display a message. This condition is shorthand for 
// _sprite.visible != true or _sprite.visible == false.
if (!_sprite.visible) {
  trace("The sprite is invisible. Set it to visible before trying this action.");
}
    
    
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// Check to see if the name is neither Bruce nor Joey. (This could
// also be rewritten using two inequality operators and a logical
// AND.)
if (!((userName == "Bruce") || (userName == "Joey"))) {
  trace ("Sorry, but only Bruce and Joey have access to this application.");
}
    
    
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for (var i:int = 0; i < 10; i++) {
  // Display the value of i.
  trace(i);
}
    
    
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for (initialization; test; update) {
  statement body
}
    
    
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for (var i:int = 0; i < 1000; i++) {
  trace(i);
}
trace ("That's the end.");
    
    
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for (var i:int = 0, j:int = 10; i < 10; i++, j--) {
  trace("i is " + i);
  trace("j is " + j);
}
    
    
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for (var i:int = 1; i <= 3; i++) {
  for (var j:int = 1; j <= 2; j++) {
    trace(i + " X " + j + " = " + (i * j));
  }
}
    
    
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1 X 1 = 1
1 X 2 = 2
2 X 1 = 2
2 X 2 = 4
3 X 1 = 3
3 X 2 = 6
    
    
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for (var i:int = 1; i <= 3; i++) {
  for (var j:int = 1; j <= 3; j++) {
    for (var k:int = 1; k <= 3; k++) {
      trace(i + " X " + j + " X " + k + " = " + (i * j * k));
    }
  }
}
    
    
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// Count backward from 10 to 1.
for (var i:int = 10; i > 0; i--) {
  trace(i);
}

// Display a sequence of square roots.
for (var i:Number = 50000; i > 2; i = Math.sqrt(i)) {
  trace(i);
}
    
    
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for (var i:int = 0; i < 20; i++) {
  _sprite.x += 10;
}
    
    
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var timer:Timer = new Timer(delay, repeatCount);
    
    
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package {
    import flash.display.Sprite;
    import flash.events.TimerEvent;
    import flash.utils.Timer;
    
    public class ExampleApplication extends Sprite {
        // Declare and initialize a variable to store the value
        // of the previous timer reading.
        private var _PreviousTime:Number = 0;
        
        public function ExampleApplication() {
            var tTimer:Timer = new Timer(500, 10);
            tTimer.addEventListener(TimerEvent.TIMER, onTimer);
            tTimer.start();
        }
        
        private function onTimer(event:TimerEvent):void {
            // Output the difference between the current timer value and
            // its value from the last time the function was called.
            trace(flash.utils.getTimer() - _PreviousTime);
            _PreviousTime = flash.utils.getTimer(); 
        }
    }
}
    
    
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package {
    import flash.display.Sprite;
    import flash.events.TimerEvent;
    import flash.utils.Timer;
    
    public class ExampleApplication extends Sprite {
        private var _square:Sprite;
        private var _circle:Sprite;
        
        
        public function ExampleApplication() {
            // Create the two sprites and draw their shapes
            _square = new Sprite();
            _square.graphics.beginFill(0xff0000);
            _square.graphics.drawRect(0, 0, 100, 100);
            _square.graphics.endFill();
            addChild(_square);
            _square.x = 100;
            _square.y = 50;
            
            _circle = new Sprite();
            _circle.graphics.beginFill(0x0000ff);
            _circle.graphics.drawCircle(50, 50, 50);
            _circle.graphics.endFill();
            addChild(_circle);
            _circle.x = 100;
            _circle.y = 200;
            
            // Create the two timers and start them
            var squareTimer:Timer = new Timer(50, 0);
            squareTimer.addEventListener(TimerEvent.TIMER, onSquareTimer);
            squareTimer.start();
            
            var circleTimer:Timer = new Timer(100, 0);
            circleTimer.addEventListener(TimerEvent.TIMER, onCircleTimer);
            circleTimer.start();
        }
        
        // Define the two handler methods
        private function onSquareTimer(event:TimerEvent):void {
            _square.x++;
        }
        
        private function onCircleTimer(event:TimerEvent):void {
            _circle.x++;
        }
    }
}
    
    
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               accessModifier function functionName ():ReturnDataType {
  // Statements go here.
}
    
    
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               functionName();
    
    
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package {
    import flash.display.Sprite;

    public class ExampleApplication extends Sprite
    {
        public function ExampleApplication() {
            for(var i:int=0;i<10;i++) {
                drawLine();
            }
        }
    
        private function drawLine():void {
            graphics.lineStyle(1, Math.random() * 0xffffff, 1);
            graphics.moveTo(Math.random() * 400, Math.random() * 400);
            graphics.lineTo(Math.random() * 400, Math.random() * 400);
        }
    }
}
    
    
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public static function showMessage( ):void {
    trace("Hello world");
}
    
    
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ExampleApplication.showMessage();
    
    
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private function average (a:Number, b:Number, c:Number):void {
  trace("The average is " + (c + b + c)/3);
}
    
    
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// Define the function such that it expects two parameters: a and b.
private function average(a:Number, b:Number):Number {
  return (a + b)/2;
}
    
    
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// When you invoke the function, pass it two arguments, such as 
// 5 and 11, which correspond to the a and b parameters. 
var averageValue:Number = average(5, 11);
    
    
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// There is no need to specify the parameters to accept when using the 
// arguments array.
private function average():Number {
  var sum:Number = 0;

  // Loop through each of the elements of the arguments array, and 
  // add that value to sum.
  for (var i:int = 0; i < arguments.length; i++) {
    sum += arguments[i];
  }
  // Then divide by the total number of arguments
  return sum/arguments.length;
}

// You can invoke average() with any number of parameters. 
var average:Number = average (1, 2, 5, 10, 8, 20);
    
    
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private function sampleFunction ():void {
  return;
  trace("Never called");
}

// Called from within another method:
sampleFunction();
// Execution continues here after returning from the sampleFuction() invocation
    
    
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private function checkPassword (password:String):void {

  // If password is not "SimonSays", exit the function.
  if (password != "SimonSays") {
    return;
  }

  // Otherwise, perform the rest of the actions.
  showForm ("TreasureMap");
}

// This method call uses the wrong password, so the 
// function exits.
checkPassword("MotherMayI");

// This method call uses the correct password, so the function 
// shows the TreasureMap form.
checkPassword("SimonSays");
    
    
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private function sampleMethod ():void {
  return "some value";  // This causes the compiler to generate an error.
}
    
    
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private function average (a:Number, b:Number):Number {
  return (a + b)/2;
}
    
    
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var playerScore:Number = average(6, 10);
trace("The player's average score is " + playerScore);
    
    
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trace("The player's average score is " + average(6, 10));
    
    
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average(6, 10);
    
    
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throw new Error("A general error occurred.");
    
    
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try {
  trace("This code is about to throw an error.");
  throw new Error("A general error occurred.");
  trace("This line won't run");
}
catch (errObject:Error) {
  trace("The catch block has been called.");
  trace("The message is: " + errObject.message);
}
    
    
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This code is about to throw an error.
The catch block has been called.
The message is: A general error occurred.
    
    
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private function displayMessage(message:String):void {
  if(message == undefined) {
    throw new Error("No message was defined.");
  }
  trace(message);
}

try {
  trace("This code is about to throw an error.");
  displayMessage();
  trace("This line won't run");
}
catch (errObject:Error) {
  trace("The catch block has been called.");
  trace("The message is: " + errObject.message);
}
    
    
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This code is about to throw an error.
The catch block has been called.
The message is: No message was defined.
    
    
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// Define a function that draws a rectangle within a specified sprite
private function drawRectangle(sprite:Sprite, newWidth:Number, newHeight:Number):void {

  // Check to see if either of the specified dimensions are not 
  // a number. If so, then thrown an error.
  if(isNaN(newWidth) || isNaN(newHeight)) {
    throw new Error("Invalid dimensions specified.");
  }

  // If no error was thrown, then draw the rectangle.
  sprite.graphics.lineStyle(1, 0, 1);
  sprite.graphics.lineTo(nWidth, 0);
  sprite.graphics.lineTo(nWidth, nHeight);
  sprite.graphics.lineTo(0, nHeight);
  sprite.graphics.lineTo(0, 0);
}
    
    
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try {

  // Attempt to draw two rectangles within the current sprite. 
  // In this example it is assumed that the variables for the dimensions 
  // are retreiving values from user input, a database, an XML file, 
  // or some other datasource.
  drawRectangle(this, widthA, heightA);
  drawRectangle(this, widthB, heightB);
}
catch(errObject:Error) {

  // If an error occurs, clear any rectangles that were drawn from 
  // the sprite. Then display a message to the user.
  this.graphics.clear();
  tOutput.text = "An error occurred: " + errObject.message;
}
    
    
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//Without using finally:
private function displayMessage(message:String):void {
  try {
    if(message == undefined) {
      throw new Error("The message is undefined.");
    }
    trace(message);
  }
  catch (errObject:Error) {
    trace(errObject.message);
  }
  trace("This is the last line displayed.");
}
//With finally:
private function displayMessage(message:String):void {
  try {
    if(message == undefined) {
      throw new Error("The message is undefined.");
    }
    trace(message);
  }
  catch (errObject:Error) {
    trace(errObject.message);
  }
  finally {
    trace("This is the last line displayed.");
  }
}
    
    
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//Without using finally:
private function displayMessage(message:String):void {
  try {
    if(message == undefined) {
      throw new Error("The message is undefined.");
    }
    trace(message);
  }
  catch (errObject:Error) {
    trace(errObject.message);
    return;
  }
  // This line won’t run if an error is caught.
  trace("This is the last line displayed.");
}
//With finally:
private function displayMessage(message:String):void {
  try {
    if(message == undefined) {
      throw new Error("The message is undefined.");
    }
    trace(message);
  }
  catch (errObject:Error) {
    trace(errObject.message);
    return;
  }
  finally {
    // This runs, even if an error is caught.
    trace("This is the last line displayed.");
  }
}

    
    
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