flash_ actionscript3.0 (语句、关键字和指令)(14)

flash actionscript3.0组建使用

下面的示例显示名为 Vehicle.as 的文件（它定义 Vehicle 类）的内容：

package {

class Vehicle {

var numDoors:Number;

var color:String;

public function Vehicle(param_numDoors:Number = 2, param_color:String = null) {

numDoors = param_numDoors;

color = param_color;

}

public function start():void {

trace("[Vehicle] start");

}

public function stop():void {

trace("[Vehicle] stop");

}

public function reverse():void {

trace("[Vehicle] reverse");

}

}

}

下例说明同一目录中名为 Car.as 的第二个 ActionScript 文件。此类扩展 Vehicle 类，通过三种方式修改它。第一种是 Car 类添加变量 fullSizeSpare 以跟踪 car 对象是否具有标准尺寸的备用轮胎。第二种是它添加特定于汽车的新方法 activateCarAlarm()，该方法用于激活汽车的防盗警报。第三种是它覆盖 stop() 函数以添加 Car 类使用防抱死制动系统来停车的事实。

package {

public class Car extends Vehicle {

var fullSizeSpare:Boolean;

public function Car(param_numDoors:Number, param_color:String, param_fullSizeSpare:Boolean) {

numDoors = param_numDoors;

color = param_color;

fullSizeSpare = param_fullSizeSpare;

}

public function activateCarAlarm():void {

trace("[Car] activateCarAlarm");

}

public override function stop():void {

trace("[Car] stop with antilock brakes");

}

}