这样解释
网页都是有它的代码的
比如本页就是:
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<div id="usrbar"><nobr><strong>fshyl</strong> 经理 四级(2465) | <a href="
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<form name="fask" action="/q" method="get"> <input type="hidden" name="ct" value="17"><input type="hidden" name="pn" value="0"><input type="hidden" name="tn" value="ikask"><input type="hidden" name="rn" value="12"><input type="hidden" name="word" value=""> <input type="hidden" name="cm" value="1"><input type="hidden" name="lm" value="394496"></form>
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<script language="JavaScript">function ask(fn){document.fask.word.value=fn.word.value;fask.submit();}</script>
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var url = escape(location.href);
function ctlSubmit(event) {
if (event.ctrlKey && event.keyCode == 13) { fdf.submit() }
}
function checkco(f,des)
{ if(f.co.value=="") {alert("请输入您的"+des); return false;}}
function limitpl(f,des)
{ if(f.co.value=="") {alert("请输入您的"+des); return false;} return limitChars(f.co,des,200);}
function checkcoAndsn(f,des)
{ if(f.co.value=="") {alert("请输入您的"+des); return false;} return limitChars(f.sn,"参考资料",60);}
function cReply(flag)
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document.getElementById('replyTB').style.display=""; }
if(flag=="no"){document.getElementById('replyTB').style.display="none"; }
location.href="#here";
}
function fixReply(flag){ setTimeout("cReply('"+flag+"')",300);}
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if(c<0)
{
echo_str = obj_Str + "限定在"+limit_len+"个字以内,请缩短字数";
alert(echo_str);
obj.focus();
return false;
}
return true;
}
function getLeftChars(varField,limit_len) {
var i = 0;
var cap = limit_len*2;
var j=0;
var runtime = (varField.value.length>cap)?(cap+1):varField.value.length;
for (i = 0; i< runtime; i++) {
if (varField.value.charCodeAt(i) > 127 || varField.value.charCodeAt(i) == 94) {
j=j+2;
}
else {
j=j+1
}
}
var leftchars = cap - j;
return (leftchars);
}
</script>
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<div class="p90">
<div class="f14 B wr">打开正规网站的网页时,是由上往下显示的,为什么?</div>
<div class="wr"><span class="red"><img src="
https://gss0.bdstatic.com/70cFsjip0QIZ8tyhnq/img/iknow/icn_point.gif" width="16" height="16" align="absmiddle"> 悬赏分:0</span> - <span class="gray">离问题结束还有 13 天 22 小时</span></div>
<div class="wr f14">就是还没下载完整个页面的时候,我们总是先看见网页的最上面部分,然后逐渐往下扩展,直到整个页面下载完毕。
<br>这种效果是在什么层面上实现的呢?编网页脚本的时候加的代码?还是浏览器解释页面的时候的一种功能?还是什么别的?
<br>高手教我……</div>
<div class="wr f14"></div>
<div align="right" class="gray wr">提问者:<a href="
http://passport.baidu.com/?detail&aid=7&default_tab=2&un=gz%5Fjason" target=_blank>gz_jason</a> - <a href="
http://www.baidu.com/search/zhidao_help.html#n5" target=_blank>魔法师 五级</a> </div>
<div><input type=button value="我来回答" onClick="location.href='#reply';"></div>
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<td width="22%" nowrap class="f14"><a name="reply"></a>我也来回答:</td>
<td width="78%"><textarea name="co" cols="50" rows="10" onKeyDown="ctlSubmit(event);" style="width:97%;"></textarea> <br> 回答即可得2分,回答被采纳则获得悬赏分以及奖励20分。 <a href="
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<br> <table width="90%" border="0" cellpadding="0" cellspacing="0">
<tr valign="top">
<td width="22%" nowrap class="f14">参考资料:</td>
<td width="78%"><input name="sn" type="text" size="50" onKeyDown="ctlSubmit(event);">
<br> <span class="style3">如果您的回答是从其他地方引用,请表明出处。</span> </td>
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<td width="78%"><input type="submit" value="提交回答" class="bnsrh">
<input type="checkbox" name="md" value="1" style="margin-left:40px;">
匿名回答 </td>
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你可以在“查看”的“原文件”中看到
因为大网站参数多
不能一下子全部下载下来
而上边的信息在代码的前边,所以就先被看到
不是什么效果