我创建了一个RSS Ticker，可以在办公室的一堆显示器上使用。这个RSS Ticker将使用Twiter Feed阅读器，天气小部件和时钟在同一个.fla中运行。
由于有大量的这些显示器，我不希望每个人都上网搜索rss，twitter和天气数据。所有这些数据都包含在从Internet下载的许多简单XML文件中。
我已经创建了一个在我们的服务器上运行的Windows服务。此服务可以完成所有工作，包括查看更新和将新数据文件下载到网络上的共享。然后我让所有显示器上的闪存仪表板从网络副本中获取信息。这样，数据就会被下载一次，其他所有内容都只能访问这个本地缓存。
一切正常，但随机的RSS代码将停止工作。我没有办法远程访问这些显示器来检查他们的错误日志，但是当我拔下以太网电缆时，我在本地测试环境中遇到完全相同的问题。仪表板尝试访问网络RSS副本，失败，然后在计时器的每个滴答声中继续失败，即使在重新建立连接之后也是如此。
我希望能够优雅地等待断开连接，然后在显示器重新连接后重新启动RSS自动收报机。我不知道如何做到这一点。以下是我的RSS相关代码：
// used to load a local xml file (stored in the same folder as the dashboard) that tells
// the dashboards which RSS feeds can be found on the network, and where they are located.
// It also contains the limits for how long each feed should be shown (both a time limit,
// and a maximimum number of feed items)
var rssListXMLLoader:URLLoader = new URLLoader();
rssListXMLLoader.addEventListener(Event.COMPLETE, rssListXMLLoaded);
rssListXMLLoader.addEventListener(IOErrorEvent.IO_ERROR, ioRSSListXMLLoaderErrorHandler);
// used to load the individual RRS feeds
var rssFeedXMLLoader:URLLoader = new URLLoader();
rssFeedXMLLoader.addEventListener(Event.COMPLETE, rssFeedXMLLoaded);
rssFeedXMLLoader.addEventListener(IOErrorEvent.IO_ERROR, ioRSSFeedXMLLoaderErrorHandler);
// rssListXMLData:XML and rssFeedXMLData:XML are used to store the XML data that is returned
// by the above loaders.
var rssListXMLData:XML = new XML();
var rssFeedXMLData:XML = new XML();
var currentRSSIndex:int = 2^10;
var currentFeedIndex:int = 2^10;
var currentLimit_Feeds:int = 2^10;
var currentLimit_Minutes:int = 2^10;
var limitStartTime:Number = new Date().time;
var gettingNewFeed = false;
// the blow Timer is used to keep the ticker moving. Each tick, it checks to see of the
// current RSS on sceen is has any text left. If it does, it removes the first letter
// causing the string to appear as if it is scrolling from right to left. If it has no
// more text, it gets the next feed.
var rssTickerTMR:Timer = new Timer(100, 0);
rssTickerTMR.addEventListener(TimerEvent.TIMER, updateRSSTicker);
rssTickerTMR.start();
updateRSSTicker();
function updateRSSTicker(e:Event = null):void
{
if(ins_rssContent.text.length == 0)
{
if(!gettingNewFeed)
{
gettingNewFeed = true;
getNewFeed();
}
}
else
{
ins_rssContent.text = ins_rssContent.text.substring(1);
}
}
// the below function checks to see if the RSS List is loaded. If it isn't it loads it,
// if it is already loaded, it calls the rssListXMLLoaded. This way, rssListXMLLoaded is
// never called unless the RSS List is already loaded.
function getNewFeed():void
{
if (rssListXMLData == "")
{
trace("Loading RSS List XML");
rssListXMLLoader.load(new URLRequest("rssFeeds.xml"));
}
else
{
rssListXMLLoaded();
}
}
// the below function manages which feed needs to be used from the list.
function rssListXMLLoaded(e:Event = null):void
{
if (e != null)
{
rssListXMLData = new XML(e.target.data);
}
currentFeedIndex++;
if (
currentFeedIndex >= rssFeedXMLData.channel["item"].length() ||
currentFeedIndex >= currentLimit_Feeds ||
new Date().time - limitStartTime >= (currentLimit_Minutes * 1000 * 60)
)
{
limitStartTime = new Date().time;
currentFeedIndex = 0;
currentRSSIndex++;
currentRSSIndex = (currentRSSIndex >= rssListXML.children().length()) ? 0 : currentRSSIndex;
currentLimit_Feeds = Number(rssListXMLData.RSSFeed[currentRSSIndex].@limitFeeds)
currentLimit_Minutes = Number(rssListXMLData.RSSFeed[currentRSSIndex].@limitMinutes)
}
try
{
rssFeedXMLLoader.load(new URLRequest(rssListXMLData.RSSFeed[currentRSSIndex]));
}
catch(e:Error)
{
trace("whoops, try again");
}
}
// the below function sets the text on the dashboard, and sets gettingNewfeed to false. This allows the
// rssTickerTMR:Timer to start removing the first letter of the newly added feed, causing the text to "scroll"
function rssFeedXMLLoaded(e:Event):void
{
rssFeedXMLData = new XML(e.target.data);
if (rssFeedXMLData.channel["item"].length() > 0)
{
var dateString:String = rssFeedXMLData.channel["item"][currentFeedIndex].pubDate;
var date:Date = new Date(Date.parse(dateString.replace(" Z","")));
if (date.toString() != "Invalid Date")
{
dateString = " @ " + FormatDate(date) + " " + FormatTime(date);
}
else
{
dateString = " @ " + dateString;
}
ins_rssTitle.text = rssFeedXMLData.channel.title + dateString;
ins_rssContent.text = " "
+ cleanDescription(rssFeedXMLData.channel["item"][currentFeedIndex].title) + " - "
+ cleanDescription(rssFeedXMLData.channel["item"][currentFeedIndex].description);
gettingNewFeed = false;
}
else
{
ins_rssContent.text = "";
gettingNewFeed = false;
}
}
// removes the things from the RSS content that I don't want.
function cleanDescription(p_string:String):String
{
if (p_string == null)
{
return '';
}
var str:String = p_string.replace(/<\/?[^>]+>/igm, ''); //remove html tags.
str = str.split("\r").join(". "); //replace line breaks with '. '
str = str.replace("\t"," "); //replace tabs with a single space.
str = str.replace(/(?:\.\s){2,}/g,". "); //replace multiple '. ' with a single one.
str = str.replace(/((https?|ftp|gopher|telnet|file|notes|ms-help):
((\/\/)|(\\\\))+[\w\d:#@%\/;$()~_?\+-=\\\.&]*)/igm, ' '); //replaces URL text with a single space
str = str.replace(/#[\w]{3,}/igm,' ') //replaces hash tags with a single space
str = str.replace(/\s{2,}/igm," "); //replace multiple spaces with a single space
return str;
}
function ioRSSListXMLLoaderErrorHandler(e:Event):void
{
trace("ioRSSListXMLLoaderErrorHandler:");
trace(e.toString());
}
// the idea below is that it sets the text to "" and sets gettingNewFeed to false, which should get the
// rssTickerTMR:Timer to try to get a band new feed. Theoretically, it should try and fail over and again
// until the network is once again accessible. This doesn't work at all.
function ioRSSFeedXMLLoaderErrorHandler(e:Event):void
{
trace("ioRSSFeedXMLLoaderErrorHandler:");
trace(e.toString());
ins_rssContent.text = "";
gettingNewFeed = false;
}
有谁知道更好的方法来解决这个问题？如果您能提供任何帮助，我将不胜感激。谢谢！
EDIT !!!
根据Will的建议，我尝试创建一个基于计时器的网络监控子系统。在我的RSS Ticker的IO_ERROR处理程序中，我停止RSS计时器，并启动网络监视计时器。每隔10秒，它会尝试从服务器下载一个文件。它继续这样做直到它工作，此时它关闭自己的计时器，重新启动RSS计时器。
理论上应该有效。不仅如此，如果我将其更改为下载网站而不是网络文件，它确实有效。使用网络文件时，一旦失败，即使重新建立连接，也会一直失败。这是我的代码：
...
function ioRSSFeedXMLLoaderErrorHandler(e:Event):void
{
rssTickerTMR.stop();
networkMonitorTMR.start();
trace("ioRSSFeedXMLLoaderErrorHandler:");
trace(e.toString());
ins_rssTitle.text = "Waiting for connection...";
ins_rssContent.text = "";
}
// netowrk monitor
var networkMonitorXMLLoader:URLLoader = new URLLoader();
networkMonitorXMLLoader.addEventListener(Event.COMPLETE, networkMonitorXMLLLoaded);
networkMonitorXMLLoader.addEventListener(IOErrorEvent.IO_ERROR, networkMonitorXMLLoaderErrorHandler);
var networkMonitorTMR:Timer = new Timer(10000,0);
networkMonitorTMR.addEventListener(TimerEvent.TIMER, checkNetwork);
function checkNetwork(e:Event = null):void
{
networkMonitorXMLLoader.load(new URLRequest("//server/share/file.xml"));
}
function networkMonitorXMLLoaderErrorHandler(e:Event = null) :void
{
trace("Still Off");
}
function networkMonitorXMLLLoaded(e:Event = null) :void
{
trace("Back On");
rssTickerTMR.start();
networkMonitorTMR.stop();
}
就像我说的，如果我切换＆＃34; // server / shar / file.xml＆＃34;到http://www.google.ca，它有效。当我拔掉我的以太网时，网络监视器启动，当我将其重新插回时，它会切换回RSS ...但是使用我的网络资源，它只会继续失败......
答案 0 :(得分：2)
处理这类问题的一般模式是触发一个超时方法，该方法在重新建立之前一直检查连接。理想情况下，您将在后台执行此操作，以便用户不会注意到。在您的情况下，如果连接失败（IO_ERROR），请将计时器设置为在指定的时间量后重试下载xml文件的方法。如果失败，请再次设置。在此期间，您可以从头开始再次显示当前项目，并在下载新Feed后对其进行更新。