优化Java Applet的加载过程
大家知道，在java applet还没有全部加载的时候，IE或Netscape会在applet对应的区域显示一块灰色的区域。那，您有没有想过用其他的方式代替它呢？
本文介绍了如何利用javascript 实现在加载java applet时候显示一段消息，比如请稍候之类的话。该段代码可以在IE和Netscape运行。
下面的代码就可以解决这个问题。
<script language="javascript"> <BR><!-- Hide script from old browsers <BR> function init(){ <BR> // Microsoft Internet Explorer <BR> if (document.all){ <BR> document.all.loading.style.visibility="hidden"; <BR> document.all.myapplet.style.visibility="visible"; <BR> document.applets[0].repaint(); <BR> } <BR> // Netscape Navigator <BR> else{ <BR> document.loading.visibility="hide"; <BR> document.myapplet.visibility="visible"; <BR> } <BR> } <BR>// --> <BR></script> <BR><BR><BODY onLoad="init()"> <BR><div id="loading" style="position:absolute;left:150;top:10;"> <BR>Please wait while Java applet loads... <BR></div> <BR><div id="myapplet" style="position:absolute;left:150;top:10;visibility:hidden"> <BR><applet code="charts.charts.class" archive="charts.jar" width="600" height="400" codebase="" VIEWASTEXT> <BR><Param name="xValue" value="1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22, <BR>23,24,25,26,27,28,29,30"> <BR><Param name="yValue" value="22,21,19,23,18,24,28,30,27,22,20,18,16,18,19,16,17,14,12, <BR>13,16,18,19,20,16,17,13,10,14,19,25"> <BR></applet> <BR></div> <BR></BODY> <BR><BR>解释： <BR> 首先，让我们来看看我们真正想做的是什么. 其实我们只不过希望把下载java程序过程中的不雅观的灰块去掉，以一些消息如正在载入，请稍候之类的画面盖住原来的灰色区域。而一旦java加载完毕，马上把该区域恢复为applet可见。 <BR> 上面的javascript代码就是实现了这个目的的一个实例。 <BR> 下面，让我来逐条解释一下我们是如何实现的。 <BR> 首先请看以下部分。 <BR><BR><BR><BR><div id="loading" style="position:absolute;left:150;top:10;"> <BR>Please wait while Java applet loads... <BR></div> <BR><div id="myapplet" style="position:absolute;left:150;top:10;visibility:hidden"> <BR><applet code="charts.charts.class" archive="charts.jar" width="600" height="400" codebase="" VIEWASTEXT> <BR><Param name="xValue" value="1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22, <BR>23,24,25,26,27,28,29,30"> <BR><Param name="yValue" value="22,21,19,23,18,24,28,30,27,22,20,18,16,18,19,16,17,14,12, <BR>13,16,18,19,20,16,17,13,10,14,19,25"> <BR></applet> <BR></div> <BR> 正如您所见到的，我用了2个层，第一个层（id为loading）可以写上一些提示消息。而第2个层(id为myapplet)在一开始是不可见的。当applet下载好了，马上把第2个层显示出来，并把第一个层设为不可见。因此，只要这2个层大小，位置必须完全一致。就可以实现我们的目标。 <BR> 现在我们只差最后一个问题需要解决：如何知道applet已经完全下载了呢？在IE和netscape中都有提供document.all这个属性，当应页面的全部内容（包括applets,图片，声音等）已经下载后该属性为真。好，这样，我们只需监测document.all是否为真，如果是，那就可以把消息所在的层设为不可见，而applet所在的层设为可见，并刷新applet的显示（因为先前applet的显示被隐藏了），否则则相反处理。 <BR><BR><BR><BR>这是处理后的代码： <BR>＜script language="javascript"＞ <BR> function init() <BR> { <BR> if (document.all) <BR> { <BR> document.all.loading.style.visibility="hidden"; <BR> document.all.myapplet.style.visibility="visible"; <BR> document.applets[0].repaint(); <BR> } <BR> else <BR> { <BR> document.loading.visibility="hide"; <BR> document.myapplet.visibility="visible"; <BR> } <BR> } <BR>＜/script＞ <BR> 大功告成。其实，用这个办法同样适用于用含有图片盖住applet直到applet开始运行为止。如何处理，我想聪明的你一定已经知道答案了。 <BR><br><br> </div> </div> </DIV> <!-- 文章内容结束 --> <!-- 拷贝连接开始 --> <DIV class=trclear></DIV> <DIV> <script type="text/javascript"><!-- google_ad_client = 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大家知道，在java applet还没有全部加载的时候，IE或Netscape会在applet对应的区域显示一块灰色的区域。那，您有没有想过用其他的方式代替它呢？
本文介绍了如何利用javascript 实现在加载java applet时候显示一段消息，比如请稍候之类的话。该段代码可以在IE和Netscape运行。
下面的代码就可以解决这个问题。
<script language="javascript"> <BR><!-- Hide script from old browsers <BR> function init(){ <BR> // Microsoft Internet Explorer <BR> if (document.all){ <BR> document.all.loading.style.visibility="hidden"; <BR> document.all.myapplet.style.visibility="visible"; <BR> document.applets[0].repaint(); <BR> } <BR> // Netscape Navigator <BR> else{ <BR> document.loading.visibility="hide"; <BR> document.myapplet.visibility="visible"; <BR> } <BR> } <BR>// --> <BR></script> <BR><BR><BODY onLoad="init()"> <BR><div id="loading" style="position:absolute;left:150;top:10;"> <BR>Please wait while Java applet loads... <BR></div> <BR><div id="myapplet" style="position:absolute;left:150;top:10;visibility:hidden"> <BR><applet code="charts.charts.class" archive="charts.jar" width="600" height="400" codebase="" VIEWASTEXT> <BR><Param name="xValue" value="1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22, <BR>23,24,25,26,27,28,29,30"> <BR><Param name="yValue" value="22,21,19,23,18,24,28,30,27,22,20,18,16,18,19,16,17,14,12, <BR>13,16,18,19,20,16,17,13,10,14,19,25"> <BR></applet> <BR></div> <BR></BODY> <BR><BR>解释： <BR> 首先，让我们来看看我们真正想做的是什么. 其实我们只不过希望把下载java程序过程中的不雅观的灰块去掉，以一些消息如正在载入，请稍候之类的画面盖住原来的灰色区域。而一旦java加载完毕，马上把该区域恢复为applet可见。 <BR> 上面的javascript代码就是实现了这个目的的一个实例。 <BR> 下面，让我来逐条解释一下我们是如何实现的。 <BR> 首先请看以下部分。 <BR><BR><BR><BR><div id="loading" style="position:absolute;left:150;top:10;"> <BR>Please wait while Java applet loads... <BR></div> <BR><div id="myapplet" style="position:absolute;left:150;top:10;visibility:hidden"> <BR><applet code="charts.charts.class" archive="charts.jar" width="600" height="400" codebase="" VIEWASTEXT> <BR><Param name="xValue" value="1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22, <BR>23,24,25,26,27,28,29,30"> <BR><Param name="yValue" value="22,21,19,23,18,24,28,30,27,22,20,18,16,18,19,16,17,14,12, <BR>13,16,18,19,20,16,17,13,10,14,19,25"> <BR></applet> <BR></div> <BR> 正如您所见到的，我用了2个层，第一个层（id为loading）可以写上一些提示消息。而第2个层(id为myapplet)在一开始是不可见的。当applet下载好了，马上把第2个层显示出来，并把第一个层设为不可见。因此，只要这2个层大小，位置必须完全一致。就可以实现我们的目标。 <BR> 现在我们只差最后一个问题需要解决：如何知道applet已经完全下载了呢？在IE和netscape中都有提供document.all这个属性，当应页面的全部内容（包括applets,图片，声音等）已经下载后该属性为真。好，这样，我们只需监测document.all是否为真，如果是，那就可以把消息所在的层设为不可见，而applet所在的层设为可见，并刷新applet的显示（因为先前applet的显示被隐藏了），否则则相反处理。 <BR><BR><BR><BR>这是处理后的代码： <BR>＜script language="javascript"＞ <BR> function init() <BR> { <BR> if (document.all) <BR> { <BR> document.all.loading.style.visibility="hidden"; <BR> document.all.myapplet.style.visibility="visible"; <BR> document.applets[0].repaint(); <BR> } <BR> else <BR> { <BR> document.loading.visibility="hide"; <BR> document.myapplet.visibility="visible"; <BR> } <BR> } <BR>＜/script＞ <BR> 大功告成。其实，用这个办法同样适用于用含有图片盖住applet直到applet开始运行为止。如何处理，我想聪明的你一定已经知道答案了。 <BR><br><br> </div> </div> </DIV> <!-- 文章内容结束 --> <!-- 拷贝连接开始 --> <DIV class=trclear></DIV> <DIV> <script type="text/javascript"><!-- google_ad_client = 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