5．按快捷键Ctrl+L打开“库”面板。右键点击“库”中的“飞鸟”元件，单击“链接”命令打开“链接属性”面板，如图4所示，并如图5所示设置。使用“链接属性”面板定义影片剪辑元件后，可以直接利用代码调用元件，而不必把元件拖拽到场景中。

图4

图5

　　6．回到“场景1”，点选“图层 1”的第1帧，按F9键打开“动作”面板，输入如下代码：

// 飞鸟动画
damp = .95;
numbirds = 30;
for (i=0; i<numbirds; i++) {
bird = attachMovie("bird", "bird"+i, i);
bird._x = Math.random()*350+20;
bird._y = Math.random()*300+20;
bird.vx = Math.random()*10-5;
bird.vy = Math.random()*10-5;
bird.k = Math.random()*.0001+.0003;
bird.gotoAndPlay(Math.round(Math.random()*20));
}
onEnterFrame = function () {
var totx = 0;
var toty = 0;
for (i=0; i<numbirds; i++) {
bird = _root["bird"+i];
totx += bird._x;
toty += bird._y;
}
avgx = totx/numbirds;
avgy = toty/numbirds;
for (i=0; i<numbirds; i++) {
bird = _root["bird"+i];
bird.vx += (avgx-bird._x)*bird.k;
bird.vy += (avgy-bird._y)*bird.k;
bird.vx += Math.random()-.5;
bird.vy += Math.random()-.5;
bird.vx *= damp;
bird.vy *= damp;
targAngle = Math.atan2(bird.vy, bird.vx)*180/Math.PI;
diff = targAngle-bird._rotation;
if (diff<-180) {
     diff += 360;
}
if (diff>180) {
     diff -= 360;
}
bird._rotation += diff*.2;
bird._x += bird.vx;
bird._y += bird.vy;
}
}

　　7．为了使该动画更有趣些，我们在以上的代码下，再添加如下代码：

// 鼠标动作
function drawToPoint(){
for(i=0;i<numbirds;i++){
bird=_root["bird"+i];
bird.vx+=(_xmouse-bird._x)*bird.k*100;
bird.vy+=(_ymouse-bird._y)*bird.k*100;
}
}
onMouseDown = drawToPoint;

　　添加这段代码后，按快捷键Ctrl+Enter测试。 当鼠标点击动画，所有的“鸟儿”就会向鼠标点击的方向飞去，很酷。整个效果到这里就全部设计好了。