在百度知道、搜搜问问等问答平台上有很多网友询问有关倒计时的问题，但是要求的时间长短不同。有点需要时限是一分钟的倒计时，有点需要几分钟的。还有的要求最后的几秒钟有报警声的，且报警的倒计时秒数要求各不相同。考虑到不同网友的不同需求，本人开发了一种可以自己设定倒计时时间和报警秒数的自定义倒计时程序，相信可以满足不同人群的需求。本篇就来谈谈制作过程，该程序具体可以分为下面三大模块：
一、将数字转换为时间。
程序是以输入数字（储存于target变量中）开始的，这个数字就是我们想要的倒计时秒数。程序要将数字转为具体时分秒。这是用一段自定义函数来实现的。先用数字除以3600，并用Math.floor()方法取整（去尾法）。然后使用原数字减去算得的小时数乘以3600后，再除以60并同样用去尾法取整算得分钟数。最后用类似的方法计算秒数。
hour = String(Math.floor(target / 3600));
minute = String(Math.floor((target - hour*3600 )/60));
second = String(target - hour * 3600 - minute * 60); hour = String(Math.floor(target / 3600));<br/> minute = String(Math.floor((target - hour*3600 )/60));<br/> second = String(target - hour * 3600 - minute * 60);
二、开始倒计时
这需要用到Timer类和TimeEvent事件。这在前面的博文中有很多实例。Timer类实例设置为每秒运行一次，每次target变量自减1，这样就实现了倒计时读秒了。
三、报警声的实现。
首先你得从网上download滴滴声的音频文件，必要时还得使用音频编辑软件编辑一下。我下载了两个音频文件，分别是滴声和嗒声。滴声实现报警，而嗒声是表示倒计时结束。准备好音频后，导入到库中，分别为ActionScript导出为Dsound类和Dasound类，使用代码创建两个实例ds和da。
我们还使用ComboBox组件来设置发报警秒数。使用变量bj（默认为30秒）和if语句来传递何时来发出报警声。
var ds:Dsound=new Dsound();
var bj:Number = 30;
var da:Dasound=new Dasound();
if (target <= bj)
{
ds.play();
}
else
{
da.play();
var ds:Dsound=new Dsound();<br/>var bj:Number = 30;<br/>var da:Dasound=new Dasound();<br/>if (target <= bj)<br/> {<br/> ds.play();<br/> }<br/>else<br/> {<br/> <br/> da.play();<br/>
完整代码：
import flash.events.MouseEvent;
import flash.utils.Timer;
import flash.events.TimerEvent;
import fl.controls.ComboBox;
import flash.events.Event;
var timer:Timer = new Timer(1000,0);
timer.addEventListener(TimerEvent.TIMER,ontimer);
var hour;
var minute;
var second;
var hours;
var minutes;
var seconds;
var target:Number;
var detect:Boolean = true;
var ds:Dsound=new Dsound();
var bj:Number = 30;
var da:Dasound=new Dasound();
//初始化
Countdown.text = "00" + ":" + "00" + ":" + "00";
startup.enabled = false;//屏蔽按钮
baojing.selectedIndex = 3;
submit.addEventListener(MouseEvent.CLICK,onclick);
baojing.addEventListener(Event.CHANGE,onchange);
function onchange(event:Event):void
{
bj = ComboBox(event.target).selectedItem.data;
}
function onclick(event:MouseEvent ):void
{
target = Number(time.text);
if (target > 0)
{
startup.enabled = true;//激活按钮
startup.label = "倒计时开始";
fdaojishi();
}
else
{
time.text = "请输入有效数字";
}
}
startup.addEventListener(MouseEvent.CLICK,timestart);
function timestart(event:MouseEvent ):void
{
if (detect)
{
timer.start();
detect = false;
startup.label = "倒计时暂停";
submit.enabled = false;
baojing.enabled = false;
time.enabled = false;
}
else
{
timer.stop();
startup.label = "倒计时开始";
detect = true;
submit.enabled = true;
baojing.enabled = true;
time.enabled=true
;
}
}
function ontimer(event:TimerEvent):void
{
target--;
if (target > 0)
{
if (target <= bj)
{
ds.play();
}
fdaojishi();
}
else
{
startup.enabled = false;
da.play();
timer.stop();
fdaojishi();
startup.label = "倒计时结束";
submit.enabled = true;
baojing.enabled = true;
time.enabled = true;
}
}
function fdaojishi()
{
hour = String(Math.floor(target / 3600));
minute = String(Math.floor((target - hour*3600 )/60));
second = String(target - hour * 3600 - minute * 60);
hours = hour < 10 "0" + hour:hour;//始终保持两位数
minutes = minute < 10 "0" + minute:minute;
seconds = second < 10 "0" + second:second;
Countdown.text = hours + ":" + minutes + ":" + seconds;
}import flash.events.MouseEvent;<br/>import flash.utils.Timer;<br/>import flash.events.TimerEvent;<br/>import fl.controls.ComboBox;<br/>import flash.events.Event;<br/><br/>var timer:Timer = new Timer(1000,0);<br/>timer.addEventListener(TimerEvent.TIMER,ontimer);<br/>var hour;<br/>var minute;<br/>var second;<br/>var hours;<br/>var minutes;<br/>var seconds;<br/>var target:Number;<br/>var detect:Boolean = true;<br/>var ds:Dsound=new Dsound();<br/>var bj:Number = 30;<br/>var da:Dasound=new Dasound();<br/><br/>//初始化<br/>Countdown.text = "00" + ":" + "00" + ":" + "00";<br/>startup.enabled = false;//屏蔽按钮<br/>baojing.selectedIndex = 3;<br/>submit.addEventListener(MouseEvent.CLICK,onclick);<br/>baojing.addEventListener(Event.CHANGE,onchange);<br/><br/>function onchange(event:Event):void<br/>{<br/> bj = ComboBox(event.target).selectedItem.data;<br/>}<br/>function onclick(event:MouseEvent ):void<br/>{<br/> target = Number(time.text);<br/> if (target > 0)<br/> {<br/> startup.enabled = true;//激活按钮<br/> startup.label = "倒计时开始";<br/> fdaojishi();<br/> }<br/> else<br/> {<br/> time.text = "请输入有效数字";<br/> }<br/>}<br/><br/>startup.addEventListener(MouseEvent.CLICK,timestart);<br/>function timestart(event:MouseEvent ):void<br/>{<br/> if (detect)<br/> {<br/> timer.start();<br/> detect = false;<br/> startup.label = "倒计时暂停";<br/> submit.enabled = false;<br/> baojing.enabled = false;<br/> time.enabled = false;<br/> }<br/> else<br/> {<br/> timer.stop();<br/> startup.label = "倒计时开始";<br/> detect = true;<br/> submit.enabled = true;<br/> baojing.enabled = true;<br/> time.enabled=true<br/> ;<br/> }<br/><br/><br/>}<br/><br/>function ontimer(event:TimerEvent):void<br/>{<br/> target--;<br/><br/> if (target > 0)<br/> {<br/><br/><br/> if (target <= bj)<br/> {<br/> ds.play();<br/> }<br/><br/> fdaojishi();<br/> }<br/> else<br/> {<br/> startup.enabled = false;<br/> da.play();<br/> timer.stop();<br/> fdaojishi();<br/> startup.label = "倒计时结束";<br/> submit.enabled = true;<br/> baojing.enabled = true;<br/> time.enabled = true;<br/> }<br/><br/>}<br/><br/>function fdaojishi()<br/>{<br/> hour = String(Math.floor(target / 3600));<br/> minute = String(Math.floor((target - hour*3600 )/60));<br/> second = String(target - hour * 3600 - minute * 60);<br/> hours = hour < 10 "0" + hour:hour;//始终保持两位数<br/> minutes = minute < 10 "0" + minute:minute;<br/> seconds = second < 10 "0" + second:second;<br/> Countdown.text = hours + ":" + minutes + ":" + seconds;<br/>}
程序使用方法：首先在输入框中输入你想倒计的秒数，再选择报警的时间（不选的话，默认30秒）。点击确定，程序会将数字转换为时分秒。点击倒计时开始按钮开始倒计时。再点击下面的按钮，程序会暂停
