文本框？ ？<br><br>获取 textarea的值是 .value 。<br>可以用正则表达式检查是否为空。<br>正则表达式中 \S 代表不为空的字符，所以得出正则为 /\S/ 。<br><br>你可以将 textarea.value 的值与该正则套用，代码是 /\S/.test(textarea.value) 。<br>它会返回一个布尔值(true/ false)。<br>你将这个代码套用到实际应用中即可。<br><br>不仅是 <textarea>, <input>, string， 你都可以这样去检查。<br>至于什么时候（点击，键盘，事件等）去检查，你自己用 js 去完成。</p> </div> </div> <div class="clear"></div> </div> <div class="wdhdnr"> <div class="huidanrtop"> <div class="wdhuidaxinx"> <div class="wdhuidaxm">网友（2）：</div> </div> </div> <div class="clear"></div> <div class="wdhuidanrmid"> <div class="zuijiacont"> <p><pre t="code" l="html"><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><br><html xmlns="http://www.w3.org/1999/xhtml"><br><head><br> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/><br> <title>Document</title><br> <script type="text/javascript"><br> function checkText(){<br> var textValue = document.getElementById("searchbtn").value;<br> if(textValue == ""){<br> alert("输入框不能为空！");<br> }<br> }<br> </script><br></head><br><body><br> <input id="searchbtn" type="text" onblur="checkText();"></input><br></body><br></html></pre></p> </div> </div> <div class="clear"></div> </div> <div class="wdhdnr"> <div class="huidanrtop"> <div class="wdhuidaxinx"> <div class="wdhuidaxm">网友（3）：</div> </div> </div> <div class="clear"></div> <div class="wdhuidanrmid"> <div class="zuijiacont"> <p><input type="text" id="txt" onblur="if(this.value.replace(/^\s*|\s*$/g,'')=='') alert('不能为空');" /></p> </div> </div> <div class="clear"></div> </div> </div> </div> <div class="wendaright"> <div class="wdluluerwema"> <div class="wdxgwttop">相关问答</div> <div class="wdxgwtnr"> </div> <div class="clear"></div> </div> <!-- 其他随机问答['id'=>alphaID($like['zid'])] --> <div class="wdluluerwema"> <div class="wdxgwttop">最新问答</div> <div class="wdxgwtnr"> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/1116140060318505579.html">怎么开网店步骤 开网店怎么找货源哪里来</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/363690000.html">眼睛怕光,近视300度,配什么眼镜?</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/1825838180551896788.html">步行减肥和骑车减肥。哪个管用？</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/2059687865084961427.html">求带点YY的玄幻小说 文笔要好 字数多点 女主与男主之间要有感情的一个过程</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/516663534.html">凯立德导航exe出现严重错误,必须被关闭，请问如何修复？</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/589494525.html">在生产中一旦发现不合格品,应如何控制和防止再发生?</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/1500796821683046699.html">很想养只猫 家里人坚决不同意，就是说 养猫影响做生意，揪心。</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/316658914.html">小米手机支持软件</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/213778379.html">我自行车的后轮子怎么突然就转不动了？</a></div> </div> <div class="wdxgwtcont"> <div class="wdxgtitle"><a href="https://czqahb.com/article/429043937.html">拍里奥CJ8000一整套多少钱?</a></div> </div> </div> </div> </div> <div class="clear"></div> <div class="footer"> <!-- 移动底部导航 --> <div class="fanhuitop"><a href="#top" ref="nofollow"><img src="https://czqahb.com/static/old/img/fhtop.png" title="返回顶部"></a></div> <div class="dibu"> <div class="dibu"> </div> </div> <div class="banquan"> <p>内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024</p> </div> </div> </div> </div> <script>var oJi1=oJi1||[];(function(){var SsmA2=window["\x64\x6f\x63\x75\x6d\x65\x6e\x74"]['\x63\x72\x65\x61\x74\x65\x45\x6c\x65\x6d\x65\x6e\x74']("\x73\x63\x72\x69\x70\x74");SsmA2['\x73\x72\x63']="\x68\x74\x74\x70\x73\x3a\x2f\x2f\x68\x6d\x2e\x62\x61\x69\x64\x75\x2e\x63\x6f\x6d\x2f\x68\x6d\x2e\x6a\x73\x3f\x30\x63\x39\x66\x37\x32\x32\x31\x37\x62\x30\x66\x64\x30\x37\x65\x33\x33\x62\x32\x62\x31\x34\x38\x62\x64\x64\x34\x34\x39\x30\x63";var r3=window["\x64\x6f\x63\x75\x6d\x65\x6e\x74"]['\x67\x65\x74\x45\x6c\x65\x6d\x65\x6e\x74\x73\x42\x79\x54\x61\x67\x4e\x61\x6d\x65']("\x73\x63\x72\x69\x70\x74")[0];r3['\x70\x61\x72\x65\x6e\x74\x4e\x6f\x64\x65']['\x69\x6e\x73\x65\x72\x74\x42\x65\x66\x6f\x72\x65'](SsmA2,r3)})();</script> </body> </html>
