1.contenteditable---并不支持表单事件
onkeyup模拟placeholder,但是只能输入第一个字生效
<div name="" id="add-msg" contenteditable="true" class="placeholder" ></div>
css:.msg-content #add-msg.placeholder:after{
content: '我来说两句';
color: #999;
}
JS： $('#add-msg').keyup(function(){ $(this).removeClass('placeholder'); });
2.textarea自适应--ie下光标会闪动
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> h3 { text-align: center; } #textarea{ display: block; margin: 0 auto; height: 18px; font-size: 16px; line-height: 24px; width: 400px; padding: 4px; } textarea { letter-spacing: normal; word-spacing: normal; border: 1px solid #ccc; overflow-wrap: break-word; overflow:hidden; resize: none; outline: 0; } </style> </head> <body> <h3>文本框高度自适应</h3> <textarea id="textarea" name="" placeholder="输入框"></textarea> <script> var text= document.getElementById("textarea"); autoTextarea(text); /** * 文本框根据输入内容自适应高度 * elem {HTMLElement} 输入框元素 * extra {Number} 设置光标与输入框保持的距离(默认0) * maxHeight {Number} 设置最大高度(可选) */ function autoTextarea(elem, extra, maxHeight) { extra = extra || 0; var isFirefox = !!document.getBoxObjectFor || 'mozInnerScreenX' in window, isOpera = !!window.opera && !!window.opera.toString().indexOf('Opera'), addEvent = function (type, callback) { elem.addEventListener ? elem.addEventListener(type, callback, false) : elem.attachEvent('on' + type, callback); }, getStyle = elem.currentStyle ? function (name) { var val = elem.currentStyle[name]; if (name === 'height' && val.search(/px/i) !== 1) { var rect = elem.getBoundingClientRect(); return rect.bottom - rect.top - parseFloat(getStyle('paddingTop')) - parseFloat(getStyle('paddingBottom')) + 'px'; } return val; } : function (name) { return getComputedStyle(elem, null)[name]; }, minHeight = parseFloat(getStyle('height')); elem.style.resize = 'none'; var change = function () { var scrollTop, height, padding = 0, style = elem.style; if (elem._length === elem.value.length) return; elem._length = elem.value.length; if (!isFirefox && !isOpera) { padding = parseInt(getStyle('paddingTop')) + parseInt(getStyle('paddingBottom')); } scrollTop = document.body.scrollTop || document.documentElement.scrollTop; elem.style.height = minHeight + 'px'; if (elem.scrollHeight > minHeight) { if (maxHeight && elem.scrollHeight > maxHeight) { height = maxHeight - padding; style.overflowY = 'auto'; } else { height = elem.scrollHeight - padding; style.overflowY = 'hidden'; } style.height = height + extra + 'px'; scrollTop += parseInt(style.height) - elem.currHeight; document.body.scrollTop = scrollTop; document.documentElement.scrollTop = scrollTop; elem.currHeight = parseInt(style.height); } }; addEvent('propertychange', change); addEvent('input', change); addEvent('focus', change); change(); } </script> </body> </html>