前段时间写前端，遇到一些模块非常有用，总结以备后用
一.input框字数监听
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>Title</title></head><body><input type="text" name="wxChoiceInfo.infoTitle" id="wxChoiceInfoInfoTitle" size="120" onkeyup="countNum(this)"/><div id="countNum" style="color: blue">还可输入<span id="num">140</span>个汉字</div><script src='/images/loading.gif' data-original="static/js/jquery-1.12.4.js"></script><script> function countNum(e){ var value=$(e).val(); var cArr = value.match(/([\u0391-\uffe5])/ig); // 返回中文的字符 var num=Math.floor((420-value.length-2*(cArr == null ? 0 : cArr.length))/3); $("#num").text(num); if(num>=0){ $("#countNum").css({"color": "#FBBC05"}); }else{ $("#countNum").css({"color": "#EA4335"}); } }</script></body></html>二.点输入框显示，点击页面其他地方隐藏功能
<!DOCTYPE HTML><html><head><meta charset="utf-8"><title>无标题文档</title><style>#div1 {width:400px; height:300px; background:#CCC; display:none;}</style><script>window.onload=function (){ var oBtn=document.getElementById('btn1'); var oDiv=document.getElementById('div1'); oBtn.onclick=function (ev) { var oEvent=ev||event; oDiv.style.display='block'; //alert('按钮被点击了'); oEvent.cancelBubble=true; }; document.onclick=function () { oDiv.style.display='none'; //alert('document被点击了'); };};</script></head><body><input id="btn1" type="button" value="显示" /><div id="div1"></div><div id="div2"></div></body></html>三.表情框
// QQ表情插件(function($){ $.fn.qqFace = function(options){ var defaults = { id : 'facebox', path : 'face/', assign : 'content', tip : 'em_' }; var option = $.extend(defaults, options); var assign = $('#'+option.assign); var id = option.id; var path = option.path; var tip = option.tip; if(assign.length<=0){ alert('缺少表情赋值对象。'); return false; } $(this).click(function(e){ var strFace, labFace; if($('#'+id).length<=0){ strFace = '<div id="'+id+'" >' + '<table border="0" cellspacing="0" cellpadding="0"><tr>'; for(var i=1; i<=75; i++){ labFace = '['+tip+i+']'; strFace += '<td><img src='/images/loading.gif' data-original="'+path+i+'.gif" onclick="$(\'#'+option.assign+'\').setCaret();$(\'#'+option.assign+'\').insertAtCaret(\'' + labFace + '\');" /></td>'; if( i % 15 == 0 ) strFace += '</tr><tr>'; } strFace += '</tr></table></div>'; } $(this).parent().append(strFace); var offset = $(this).position(); var top = offset.top + $(this).outerHeight(); $('#'+id).css('top',top); $('#'+id).css('left',offset.left); $('#'+id).show(); e.stopPropagation(); }); $(document).click(function(){ $('#'+id).hide(); $('#'+id).remove(); }); };})(jQuery);jQuery.extend({ unselectContents: function(){ if(window.getSelection) window.getSelection().removeAllRanges(); else if(document.selection) document.selection.empty(); } }); jQuery.fn.extend({ selectContents: function(){ $(this).each(function(i){ var node = this; var selection, range, doc, win; if ((doc = node.ownerDocument) && (win = doc.defaultView) && typeof win.getSelection != 'undefined' && typeof doc.createRange != 'undefined' && (selection = window.getSelection()) && typeof selection.removeAllRanges != 'undefined'){ range = doc.createRange(); range.selectNode(node); if(i == 0){ selection.removeAllRanges(); } selection.addRange(range); } else if (document.body && typeof document.body.createTextRange != 'undefined' && (range = document.body.createTextRange())){ range.moveToElementText(node); range.select(); } }); }, setCaret: function(){ //if(!$.browser.msie) return; var initSetCaret = function(){ var textObj = $(this).get(0); //textObj.caretPos = document.selection.createRange().duplicate(); }; $(this).click(initSetCaret).select(initSetCaret).keyup(initSetCaret); }, insertAtCaret: function(textFeildValue){ var textObj = $(this).get(0); if(document.all && textObj.createTextRange && textObj.caretPos){ var caretPos=textObj.caretPos; caretPos.text = caretPos.text.charAt(caretPos.text.length-1) == '' ? textFeildValue+'' : textFeildValue; } else if(textObj.setSelectionRange){ var rangeStart=textObj.selectionStart; var rangeEnd=textObj.selectionEnd; var tempStr1=textObj.value.substring(0,rangeStart); var tempStr2=textObj.value.substring(rangeEnd); textObj.value=tempStr1+textFeildValue+tempStr2; textObj.focus(); var len=textFeildValue.length; textObj.setSelectionRange(rangeStart+len,rangeStart+len); textObj.blur(); }else{ textObj.value+=textFeildValue; } } });qqface.js
<!doctype html><html lang="en"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"><title>qqFace</title><link href="css/bootstrap.min.css" rel="stylesheet" media="screen"><link rel="stylesheet" href="css/reset.css"> <style>.comment{width:680px; margin:20px auto; position:relative; background:#fff; padding:20px 50px 50px; border:1px solid #DDD; border-radius:5px;}.comment h3{height:28px; line-height:28px}.com_form{width:100%; position:relative}.input{width:99%; height:60px; border:1px solid #ccc}.com_form p{height:28px; line-height:28px; position:relative; margin-top:10px;}span.emotion{width:42px; height:20px;}span.emotion:hover{background-position:2px -28px}.qqFace{margin-top:4px;background:#fff;padding:2px;border:1px #dfe6f6 solid;}.qqFace table td{padding:0px;}.qqFace table td img{cursor:pointer;border:1px #fff solid;}.qqFace table td img:hover{border:1px #0066cc solid;}#show{width:770px; margin:20px auto; background:#fff; padding:5px; border:1px solid #DDD; vertical-align:top;}.sub_btn { position:absolute; right:0px; top:0; display: inline-block; zoom: 1; /* zoom and *display = ie7 hack for display:inline-block */ *display: inline; vertical-align: baseline; margin: 0 2px; outline: none; cursor: pointer; text-align: center; font: 14px/100% Arial, Helvetica, sans-serif; padding: .5em 2em .55em; text-shadow: 0 1px 1px rgba(0,0,0,.6); -webkit-border-radius: 3px; -moz-border-radius: 3px; border-radius: 3px; -webkit-box-shadow: 0 1px 2px rgba(0,0,0,.2); -moz-box-shadow: 0 1px 2px rgba(0,0,0,.2); box-shadow: 0 1px 2px rgba(0,0,0,.2); color: #e8f0de; border: solid 1px #538312; background: #64991e; background: -webkit-gradient(linear, left top, left bottom, from(#7db72f), to(#4e7d0e)); background: -moz-linear-gradient(top, #7db72f, #4e7d0e); filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#7db72f', endColorstr='#4e7d0e');}.sub_btn:hover { background: #538018; background: -webkit-gradient(linear, left top, left bottom, from(#6b9d28), to(#436b0c)); background: -moz-linear-gradient(top, #6b9d28, #436b0c); filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#6b9d28', endColorstr='#436b0c');}</style></head><body> <div id="show"></div> <div > <div > <textarea id="saytext" ></textarea> <p><input type="button" value="提交"><span >表情</span></p> </div> </div> <script src='/images/loading.gif' data-original="js/jquery.min.js"></script><script type="text/javascript" src='/images/loading.gif' data-original="js/jquery.qqFace.js"></script><script type="text/javascript">$(function(){ $('.emotion').qqFace({ id : 'facebox', assign:'saytext', path:'arclist/' //表情存放的路径 }); $(".sub_btn").click(function(){ var str = $("#saytext").val(); $("#show").html(replace_em(str)); });});//查看结果function replace_em(str){ str = str.replace(/\</g,'<'); str = str.replace(/\>/g,'>'); str = str.replace(/\n/g,'<br/>'); str = str.replace(/\[em_([0-9]*)\]/g,'<img src='/images/loading.gif' data-original="arclist/$1.gif" border="0" />'); return str;}</script></body></html>四. 文件本地预览上传
function handleFileSelect(evt) { var files = evt.target.files; // Loop through the FileList and render image files as thumbnails. for (var i = 0, f; f = files[i]; i++) { // Only process image files. if (!f.type.match('image.*')) { continue; } var reader = new FileReader(); // Closure to capture the file information. reader.onload = (function(theFile) { return function(e) { // Render thumbnail. var span = document.createElement('span'); span.innerHTML = [ '<img src='/images/loading.gif' data-original="', e.target.result, '" title="', escape(theFile.name), '"/>' ].join(''); document.getElementById('list').insertBefore(span, null); }; })(f); // Read in the image file as a data URL. reader.readAsDataURL(f); } } document.getElementById('files').addEventListener('change', handleFileSelect, false);fileLocalUpload.js
<input type="file" id="files" multiple /><output id="list"></output>
原标题：JS代码实用代码实例（输入框监听，点击显示点击其他地方消失,文件本地预览上传)
关键词：JS
我知道了 