各位，大佬，下面这段代码加一点东西限制角色不能移动出舞台，请问怎么加，我是非专业的大学生，现在要完成选修课的作业，请各位高抬贵手，谢谢。
var player = addChild( new soilder( ) );
var leftIsPressed:Boolean = false;
var rightIsPressed:Boolean = false;
var upIsPressed:Boolean = false;
var downIsPressed:Boolean = false;
addEventListener( Event.ENTER_FRAME, doEveryFrame );
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownHandler);
stage.addEventListener(KeyboardEvent.KEY_UP, keyUpHandler);
function keyDownHandler(e:KeyboardEvent):void
{
switch(e.keyCode) {
//case Keyboard.LEFT : leftIsPressed = true; break;
//case Keyboard.RIGHT : rightIsPressed = true; break;
//case Keyboard.UP : upIsPressed = true; break;
//case Keyboard.DOWN : downIsPressed = true; break;
case Keyboard.A: leftIsPressed = true; break;
case Keyboard.D : rightIsPressed = true; break;
case Keyboard.W: upIsPressed = true; break;
case Keyboard.S: downIsPressed = true; break;
}
}
function keyUpHandler(e:KeyboardEvent):void
{
switch(e.keyCode) {
//case Keyboard.LEFT : leftIsPressed = false; break;
//case Keyboard.RIGHT : rightIsPressed = false; break;
//case Keyboard.UP : upIsPressed = false; break;
//case Keyboard.DOWN : downIsPressed = false; break;
case Keyboard.A : leftIsPressed = false; break;
case Keyboard.D : rightIsPressed = false; break;
case Keyboard.W : upIsPressed = false; break;
case Keyboard.S: downIsPressed = false; break;
}
}
function doEveryFrame( e:Event ):void
{
if (downIsPressed)
{
player.y = player.y + 20
}
if (rightIsPressed)
{
player.x = player.x + 20
}
if (leftIsPressed)
{
player.x = player.x - 20
}
if (upIsPressed)
{
player.y = player.y - 20
}
}

flash吧已经回复