Ⅰ html实现图片上传
html：
<section class="upload-section">
<article class="upload-piclist">
<div class="upload-file">
<input type="file" id="file" accept="image/*" multiple onchange="imgChange()"/>
</div>
</article>
</section>
css:
/* body {
margin: 0;
padding: 0;
max-width: 414px;
margin: 0 auto;
} */
.upload-fh {
background-image: url('data:image/png;base64,/NlyAAAD1klEQVRoQ+++d972/++T//++XRa2drCkDwG8E4B+A9BH8maZ2FrBkj4D8GYA+hHAKyT/thSRYiGnZtgJogeSgFNglYkgX/+/YOlgSf0AohTOkoBekj/B19KwBdcOz/++5mGm4WttHa3D892xJAspTwXX3Pae//+/+mIZ6GzAjt7iJ49RraWhf+gWnRXY0RaY2Frd/+/yB7sE9nCeW+p8Hjbm2nDAKwcahbAdGPfTGt3nM53/V00ckNMKWY8LAAAAABJRU5ErkJggg==');
background-repeat: no-repeat;
background-size: 100% 100%;
height: 30px;
width: 30px;
}
.upload-hedaer {
height: 55px;
display: grid;
grid-template-columns: repeat(3, 1fr);
padding: 0 10px;
box-sizing: border-box;
align-items: center;
text-align: center;
background: #287cff;
color: #fff;
border-bottom: 1px solid #efefef;
font-size: 19px;
}
.upload-hedaer div:last-child {
text-align: right;
}
.upload-textarea {
width: 100%;
height: 60px;
font-size: 28px;
border: 1px solid #efefee;
max-height: 300px;
}
.upload-article-text {
width: 100%;
padding: 10px;
box-sizing: border-box;
}
.upload-file {
position: relative;
background: url('../images/z_add.png') no-repeat 50%/100% 100%;
/* width: 100px; */
height: 120px;
order: 9;
}
.upload-piclist {
padding: 0 10px;
box-sizing: border-box;
display: grid;
grid-template-columns: repeat(3, 120px);
justify-content: space-between;
grid-gap: 14px;
}
#file {
width: 100%;
height: 100%;
opacity: 0;
}
.upload-Picitem {
width: 100%;
height: 120px;
}
.upload-Picitem>img {
width: 100%;
height: 100%;
object-fit: cover;
}
.submit {
padding: 15px 0;
background-color: #287cff;
color: #fff;
text-align: center;
margin: 10px;
font-size: 20px;
border-radius: 10px;
}
.upload-sm {
padding: 10px;
box-sizing: border-box;
color: gray;
}
.upload-sm ol>li {
margin-bottom: 10px;
}
js:let picmax = 9; //限制上传数量
function imgChange() {
let file = document.getElementById('file').files;
let imglist = document.querySelectorAll('.upload-Picitem');
let piclist = document.getElementsByClassName('upload-piclist')[0];
let filelist = file.length + imglist.length > picmax ? 9 - imglist.length : file.length + imglist.length;
if (file.length + imglist.length >= 9) {
let uploadfile = document.getElementsByClassName('upload-file')[0]
uploadfile.style.display = "none"
}
for (let i = 0; i < filelist; i++) {
readerfile(file[i]).then(e => {
let html = document.createElement('div');
html.className = 'upload-Picitem'
html.innerHTML = '<img src=' + e + ' alt="pic">'
piclist.appendChild(html);
})
}
}
function readerfile(file) {
return new Promise((resolve, reject) => {
let reader = new FileReader();
reader.addEventListener("load", function() {
resolve(reader.result);
}, false)
if (file) {
reader.readAsDataURL(file)
}
})
}
//提交
function submit() {
let imglist = []
let text = document.getElementsByClassName('upload-textarea')[0].value
let piclist = document.querySelectorAll('.upload-Picitem');
for (let i = 0; i < piclist.length; i++) {
imglist.push(piclist[i].lastChild.src)
}
console.log("发布内容：", text)
console.log("图片列表：", imglist)
}
//textarea高度自适应
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();
};
pic:z_add.png
Ⅱ Div中插入图片的方法有哪几种
1、<img src=".../.../" alt=""/>这是直接放一张图片
2、可以在div的css里设置背景图片:background:.../.../;
Ⅲ 急！想要实现一个功能，就是上传一张图片显示在一个div中
解决方法有两种：
第一种，让图片和布局宽度高度成等比例，这样CSS设置死宽度和高度，图片也是等比例缩小，图片也不会变形。
比如淘宝，要求店铺主上传产品封面图片是正方形的，为什么，因为图片宝贝展示列表都是正方形的排版布局，这样要求上传合适正方形宝贝封面图片，也是让图片不变形。
所以有条件的情况下，大家将首页、图片列表页的布局宽度高度保持一致，上传图片时候将图片先进行处理为布局宽度高度时等比例放大尺寸的。
第二种，使用CSS max-width和max-height实现图片自动等比例缩小
很简单我们要使用到max-width和max-height,这样即可设置对象图片最大宽度和最大高度，这样图片就会等比例缩放图片，然图片相对不变形清晰。
Ⅳ mvc视图中怎么上传图片并显示
如果只是上传的话那太容易了，如果还要显示那就难了，因为要显示的话就不能只向服务器提交一次请求，必须异步提交。下面的例子是我亲自写的，异步提交上传图片并预览。全部代码都在。
返回到前台页面的JSON格式对象是以类的对象。
publicclassReturnImage
{
publicstringbig{get;set;}
publicstringsmall{get;set;}
publicstringisSuccessfull{get;set;}
publicstringmessage{get;set;}
}
对于上传和生成缩略图，请自行完成，以下是ASP.NETMVC的例子。
publicclassHomeController:Controller
{
//
//GET:/Home/
publicActionResultIndex()
{
returnView();
}
///<summary>
///上传图片
///</summary>
///<returns></returns>
publicActionResultUploadImage()
{
//定义错误消息
JsonResultmsg=newJsonResult();
try
{
//接受上传文件
HttpPostedFileBasepostFile=Request.Files["upImage"];
if(postFile!=null)
{
DateTimetime=DateTime.Now;
//获取上传目录转换为物理路径
stringuploadPath=Server.MapPath("~/UploadFiles/"+time.Year+"/"+time.ToString("yyyyMMdd")+"/");
//文件名
stringfileName=time.ToString("yyyyMMddHHmmssfff");
//后缀名称
stringfiletrype=System.IO.Path.GetExtension(postFile.FileName);
//获取文件大小
longcontentLength=postFile.ContentLength;
//文件不能大于2M
if(contentLength<=1024*2048)
{
//如果不存在path目录
if(!Directory.Exists(uploadPath))
{
//那么就创建它
Directory.CreateDirectory(uploadPath);
}
//保存文件的物理路径
stringsaveFile=uploadPath+fileName+"_big"+filetrype;
try
{
//保存文件
postFile.SaveAs(saveFile);
//保存缩略图的物理路径
stringsmall=uploadPath+fileName+"_small"+filetrype;
MakeThumbnail(saveFile,small,320,240,"W");
ReturnImageimage=newReturnImage();
image.big="/UploadFiles/"+time.Year+"/"+time.ToString("yyyyMMdd")+"/"+fileName+"_big"+filetrype;
image.small="/UploadFiles/"+time.Year+"/"+time.ToString("yyyyMMdd")+"/"+fileName+"_small"+filetrype;
msg=Json(image);
}
catch
{
msg=Json("上传失败");
}
}
else
{
msg=Json("文件大小超过限制要求");
}
}
else
{
msg=Json("请选择文件");
}
}
catch(Exceptione)
{
;
}
msg.ContentType="text/html";
returnmsg;
}
///<summary>
由于回答超过最大限制，///生成缩略图的代码请向我索取
Ⅳ 求js或JQ代码，实现图片上传后在指定的div中以背景图显示
如果是background的话使用 $("div").css("background-image","图片地址")，如果使用的img的话使用$("div").attr("src","地址");关键就是获取图片地址给弄上去
Ⅵ 如何用html实现按钮上传图片，并且图片缩略图显示在按钮上方
+分采纳
<html>
<head>
<style>
*{
margin: 0;
padding: 0;
box-sizing: border-box;
-webkit-tap-highlight-color: rgba(0,0,0,0);
}
</style>
</head>
<body>
<div></div>
<input type="file" multiple="multiple" onchange="upload(event)">
</body>
</html>
<script type="text/javascript">
const [el,stage] = [
document.querySelector('input'),
document.querySelector('div'),
]
function upload({target}){
if(!target.files.length) return;
for(const file of target.files){
const img = new Image();
img.src = URL.createObjectURL(file);
stage.appendChild(img);
}
}
</script>