还有另一个关于这个的帖子,我试过了。但有一个问题:如果你删除内容,文本区域不会缩小。我找不到任何方法将其缩小到正确的大小- clientHeight值返回为文本区域的完整大小,而不是它的内容。
该页面的代码如下:
function FitToContent(id, maxHeight)
{
var text = id && id.style ? id : document.getElementById(id);
if ( !text )
return;
var adjustedHeight = text.clientHeight;
if ( !maxHeight || maxHeight > adjustedHeight )
{
adjustedHeight = Math.max(text.scrollHeight, adjustedHeight);
if ( maxHeight )
adjustedHeight = Math.min(maxHeight, adjustedHeight);
if ( adjustedHeight > text.clientHeight )
text.style.height = adjustedHeight + "px";
}
}
window.onload = function() {
document.getElementById("ta").onkeyup = function() {
FitToContent( this, 500 )
};
}
有人觉得满意吗?没有混乱的滚动,和唯一的JS我喜欢关于它是如果你计划在模糊保存数据…显然,它在所有流行的浏览器上都是兼容的:http://caniuse.com/#feat=contenteditable
只要把它设置成文本框的样式,它就会自动调整大小……将它的最小高度设置为首选文本高度。
这种方法的最酷之处在于,您可以在某些浏览器上保存和标记。
http://jsfiddle.net/gbutiri/v31o8xfo/
var _auto_value = '';
$(document).on('blur', '.autosave', function(e) {
var $this = $(this);
if ($this.text().trim() == '') {
$this.html('');
}
// The text is here. Do whatever you want with it.
$this.addClass('saving');
if (_auto_value !== $this.html() || $this.hasClass('error')) {
// below code is for example only.
$.ajax({
url: '/echo/json/?action=xyz_abc',
data: 'data=' + $this.html(),
type: 'post',
datatype: 'json',
success: function(d) {
console.log(d);
$this.removeClass('saving error').addClass('saved');
var k = setTimeout(function() {
$this.removeClass('saved error')
}, 500);
},
error: function() {
$this.removeClass('saving').addClass('error');
}
});
} else {
$this.removeClass('saving');
}
}).on('focus mouseup', '.autosave', function() {
var $this = $(this);
if ($this.text().trim() == '') {
$this.html('');
}
_auto_value = $this.html();
}).on('keyup', '.autosave', function(e) {
var $this = $(this);
if ($this.text().trim() == '') {
$this.html('');
}
});
body {
background: #3A3E3F;
font-family: Arial;
}
label {
font-size: 11px;
color: #ddd;
}
.autoheight {
min-height: 16px;
font-size: 16px;
margin: 0;
padding: 10px;
font-family: Arial;
line-height: 20px;
box-sizing: border-box;
-o-box-sizing: border-box;
-moz-box-sizing: border-box;
-webkit-box-sizing: border-box;
overflow: hidden;
display: block;
resize: none;
border: 0;
outline: none;
min-width: 200px;
background: #ddd;
max-height: 400px;
overflow: auto;
}
.autoheight:hover {
background: #eee;
}
.autoheight:focus {
background: #fff;
}
.autosave {
-webkit-transition: all .2s;
-moz-transition: all .2s;
transition: all .2s;
position: relative;
float: none;
}
.autoheight * {
margin: 0;
padding: 0;
}
.autosave.saving {
background: #ff9;
}
.autosave.saved {
background: #9f9;
}
.autosave.error {
background: #f99;
}
.autosave:hover {
background: #eee;
}
.autosave:focus {
background: #fff;
}
[contenteditable=true]:empty:before {
content: attr(placeholder);
color: #999;
position: relative;
top: 0px;
/*
For IE only, do this:
position: absolute;
top: 10px;
*/
cursor: text;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<label>Your Name</label>
<div class="autoheight autosave contenteditable" contenteditable="true" placeholder="Your Name"></div>
这是一种基于行的方法,允许您为文本区域设置最大行数,之后文本区域将显示滚动条。除了以rows属性的形式调整它的高度之外,它还会在键入或执行剪切和粘贴之类的操作时自动扩展它的宽度。
如果文本区域没有任何内容,只有一个占位符,它将根据占位符文本调整其宽度和高度。
这个版本的一个缺点是,它将继续无限增加它的宽度基于文本宽度。因此,你需要为文本区域设置一个max-width值。简单的max-width: 100%;也会有效果。这个宽度扩展特性主要基于type="text"的输入字段。你可以在这个答案中了解更多。
const textarea = document.querySelector('textarea');
setTextareaWidthHeight(textarea);
textarea.addEventListener('input', setTextareaWidthHeight.bind(this, textarea));
function getInputWidth(element) {
const text = element.value || element.placeholder;
const elementStyle = window.getComputedStyle(element);
const fontProperty = elementStyle.font;
const horizontalBorder = parseFloat(elementStyle.borderLeftWidth) + parseFloat(elementStyle.borderRightWidth);
const horizontalPadding = parseFloat(elementStyle.paddingLeft) + parseFloat(elementStyle.paddingRight);
const canvas = document.createElement('canvas');
const context = canvas.getContext('2d');
context.font = fontProperty;
const textWidth = context.measureText(text).width;
const totalWidth = horizontalBorder + horizontalPadding + textWidth + "px";
return totalWidth;
}
function setTextareaWidthHeight(element) {
// store minimum and maximum rows attribute value that should be imposed
const minRows = 1;
const maxRows = 5;
// store initial inline overflow property value in a variable for later reverting to original condition
const initialInlineOverflowY = element.style.overflowY;
// change overflow-y property value to hidden to overcome inconsistent width differences caused by any scrollbar width
element.style.overflowY = 'hidden';
const totalWidth = getInputWidth(element);
element.style.width = totalWidth;
let rows = minRows;
element.setAttribute("rows", rows);
while (rows <= maxRows && element.scrollHeight !== element.clientHeight) {
element.setAttribute("rows", rows);
rows++;
}
// change overflow to its original condition
if (initialInlineOverflowY) {
element.style.overflowY = initialInlineOverflowY;
} else {
element.style.removeProperty("overflow-y");
}
}
textarea {
max-width: 100%;
}
<textarea placeholder="Lorem ipsum dolor sit amet"></textarea>
你可以使用这段代码来计算一个textarea需要的行数:
textarea.rows = 1;
if (textarea.scrollHeight > textarea.clientHeight)
textarea.rows = textarea.scrollHeight / textarea.clientHeight;
在输入和窗口:resize事件上计算它以获得自动调整大小的效果。Angular中的例子:
模板代码:
<textarea rows="1" reAutoWrap></textarea>
auto-wrap.directive.ts
import { Directive, ElementRef, HostListener } from '@angular/core';
@Directive({
selector: 'textarea[reAutoWrap]',
})
export class AutoWrapDirective {
private readonly textarea: HTMLTextAreaElement;
constructor(el: ElementRef) {
this.textarea = el.nativeElement;
}
@HostListener('input') onInput() {
this.resize();
}
@HostListener('window:resize') onChange() {
this.resize();
}
private resize() {
this.textarea.rows = 1;
if (this.textarea.scrollHeight > this.textarea.clientHeight)
this.textarea.rows = this.textarea.scrollHeight / this.textarea.clientHeight;
}
}
jQuery的解决方案是设置文本区域的高度为'auto',检查scrollHeight,然后调整文本区域的高度,每次文本区域改变(JSFiddle):
$('textarea').on( 'input', function(){
$(this).height( 'auto' ).height( this.scrollHeight );
});
如果你在动态添加文本区域(通过AJAX或其他方式),你可以在$(document)中添加这个。准备好确保所有带有类'autoheight'的文本区域保持与它们的内容相同的高度:
$(document).on( 'input', 'textarea.autoheight', function() {
$(this).height( 'auto' ).height( this.scrollHeight );
});
测试和工作在Chrome, Firefox, Opera和IE。还支持剪切和粘贴,长字等。