Js仿微博插入话题功能，点击插入文字

发布时间：2018-09-07 21:02:42 所属栏目：Unix 来源：站长网

导读：Js微博插入话题功能，仿新浪微博插入新话题效果，当点击或选择话题后，自动将话题文字插入到微博文本框中，用户不用再输入了，提升用户体验。两点说明： 1.获取光标位置IE下用到了createRange的方法，标准下用到selectionStart 2.设置光标选中IE下用到了

　　Js微博插入话题功能，仿新浪微博插入新话题效果，当点击或选择话题后，自动将话题文字插入到微博文本框中，用户不用再输入了，提升用户体验。两点说明：

　　1.获取光标位置IE下用到了createRange的方法，标准下用到selectionStart

　　2.设置光标选中IE下用到了createTextRange，标准下用到了setSelectionRange

　　示例：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Js仿微博插入话题功能</title> <script> //插入话题 function inTopic(id, str){ var str = str || "请在这里输入自定义话题"; str = "#" + str + "#"; var reg = new RegExp(str), oTextarea = document.getElementById(id), oValue = oTextarea.value, val_index = 0, val_match, val_pos; if(reg.test(oValue)){ val_match = oValue.match(reg); val_index = val_match.index; } else{ val_pos = getTextPos(oTextarea); val_index = val_pos.start; rangeText(oTextarea, str); } selectText(oTextarea, val_index + 1, val_index + str.length - 1); } //光标的当前位置 function getTextPos(obj){ if(!obj || obj.offsetWidth == 0){ return false; } var t = obj, start = 0, end = 0, value = '', range, range_all; value = t.value; if(typeof(t.selectionStart) == "number"){ start = t.selectionStart; end = t.selectionEnd; } else if(document.selection && t.offsetWidth>0){ t.focus(); range = document.selection.createRange(); if(range.parentElement() == t){ range_all = document.body.createTextRange(); range_all.moveToElementText(t); for(start = 0; range_all.compareEndPoints("StartToStart", range) < 0; start++){ range_all.moveStart('character', 1); } for(var i = 0; i <= start; i++){ if(t.value.charAt(i) == 'n'){ start++; } } range_all.moveToElementText(t); for(end = 0; range_all.compareEndPoints('StartToEnd', range) < 0; end++){ range_all.moveStart('character', 1); } for(var i = 0; i <= end; i++){ if(t.value.charAt(i) == 'n'){ end++; } } } } else{ start = value.length; end = value.length; } return{ start: start, end: end } } //光标处替换的文本 function rangeText(obj, val, num){ if(!obj || obj.offsetWidth == 0){ return false; } var t = obj, start = 0, end = 0, value = '', val_start = '', val_end = '', pos; var userAgent = navigator.userAgent.toLowerCase(), ie = /msie/.test(userAgent) && !/opera/.test(userAgent); if(ie && t.nodeName.toLocaleLowerCase() != 'textarea'){ t.value = val; t.focus; return; } value = t.value; pos = getTextPos(t); start = pos.start; end = pos.end; if (typeof num=='number'){ start = start - num; } val_start = value.substring(0, start); val_end = value.substring(end); t.value = val_start + val + val_end; if (typeof num=='number'){ end = end - num; } selectText(t,end+val.length,end+val.length); } //光标定位到指定文本 function selectText(obj, start, stop){ if(!obj || obj.offsetWidth == 0){ return false; } var range; if(obj.setSelectionRange){ obj.setSelectionRange(start,stop); } else{ range = obj.createTextRange(); range.collapse(true); range.moveStart("character",start); range.moveEnd("character",stop-start); range.select(); } obj.focus(); } </script> <style type="text/css"> body{margin:0;} .box{width:600px;height:200px;background:url(/uploads/allimg/1106/weibo.png) no-repeat;margin:60px auto;position:relative;} #textarea{ border: medium none;font-size: 14px;height: 70px;line-height: 124%;padding: 0;width: 475px;overflow:hidden;resize: none;position:absolute;left:62px; top:55px;outline: none;} .button{width:100px;height:30px;background:url(/uploads/allimg/1106/button.gif) 0 0 no-repeat;position:absolute;left:442px;top:135px;} .button:hover{background-position:0 -30px;} .button:active{background-position:0 -60px;} .topic{position:absolute;left:72px;top:136px;height:26px;line-height:26px;text-decoration:none;color:#fff;font-size:12px;background:url(/uploads/allimg/1106/topic.gif) no-repeat 0 7px;padding-left:14px;} </style> </head> <body> <div class="box"> <textarea id="textarea" accesskey="1" tabindex="1" style="font-family: Tahoma,宋体;"></textarea> <a href="" class="button"></a> <a href="###" class="topic" onclick="inTopic('textarea','烈火学院VeryHuo.COM')">话题</a> </div> </body> </html><br /><center>如不能显示效果，请按Ctrl+F5刷新本页，更多网页代码：<a href='http://www.veryhuo.com/' target='_blank'>http://www.veryhuo.com/</a></center>
提示：可修改后代码再运行!

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