方法一、直接在textarea中添加oninput方法:
<textarea οninput="this.style.height = this.scrollHeight + 'px';"></textarea>
說明:
在IE下可以根據輸入的内容自适應高度,但是在谷歌浏覽器下随着輸入的字數越多,高度越高, 比實際的高度要高出很多;
方法二、自定義高度設定方法:
<script>
var autoTextarea = function (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>
說明:
在IE和谷歌下均能自适應高度;但是動态給文本框指派的時候,高度不能自适應,需要滑鼠點選到文本框才能實作高度自适應的效果;
方法三:為了達到完美效果,要綜合使用方法一和方法二;
使用執行個體:
1、樣式:
.areaKFYYSM {
margin-top: 5px;
min-height: 35px !important;
height: auto;
width: 96% !important;
}
2、文本框:
<textarea class="areaKFYYSM" id="areaKFYYSM" οninput="this.style.height = this.scrollHeight + 'px';" ></textarea>
<input id="btn_Ok" type=button value='初始化值' class="img-smallbtn btn-ok" οnclick="kfyysmChangeBFZ()" />
3、初始化方法設定文本框高度方法:
$(function () {
// 為每一個textarea綁定事件使其高度自适應
$.each($("textarea"), function (i, n) {
autoTextarea($(n)[0]);
});
});
4、文本框動态指派後,調用input事件:
function kfyysmChangeBFZ() {
// 給文本框初始值
$("#areaKFYYSM").val("文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值文本框初始化值");
//文本框高度自适應
$("#areaKFYYSM").trigger("input");
}
參照網址:
https://blog.csdn.net/fxss5201/article/details/63267432