html+css+js 实现拍照预览上传图片功能

    
 
 
身份证
 
 
 
身份证正面照
 
 
身份证反面照
 提交 

 body{ margin: 0 } .content{ padding:0.5rem; display: flex; align-items: center; border-bottom: 1px #999 solid } .label{ width:5rem; } .img-area{ flex:1 } .container{ background-color:#e7e7e7; position: relative; } .container div{ text-align: center; padding:0.5rem 0 } .container input{ opacity:0; filter:alpha(opacity=0); height: 100%; width: 100%; position: absolute; top: 0; left: 0; z-index: 9; } .container p{ font-size: 0.9rem; color:#999 } .btn{ background-color: #4363ab; color: #fff; text-align: center; padding: 0.5rem 1rem; width:80%; border-radius: 0.2rem; margin: 2rem auto; font-weight: 600; font-size: 1.2rem }

 window.onload=function(){ document.getElementById("id-face").addEventListener("change", function(){ onFileChange(this,"face-result","face-empty-result") }); document.getElementById("id-back").addEventListener("change", function(){ onFileChange(this,"back-result","back-empty-result") }); document.getElementsByClassName("btn")[0].addEventListener("click", function(){ submit(); }); }; /** * 选中图片时的处理 * @param {*} fileObj input file元素 * @param {*} el //选中后用于显示图片的元素ID * @param {*} btnel //未选中图片时显示的按钮区域ID */ function onFileChange(fileObj,el,btnel){ var windowURL = window.URL || window.webkitURL; var dataURL; var imgObj = document.getElementById(el); document.getElementById(btnel).style.display="none"; imgObj.style.display="block"; if (fileObj && fileObj.files && fileObj.files[0]) { dataURL = windowURL.createObjectURL(fileObj.files[0]); imgObj.src=dataURL; } else { dataURL = fileObj.value; imgObj.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)"; imgObj.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = dataURL; } } /** * 将图片压缩后返回base64格式的数据 * @param {*} image img元素 * @param {*} width 压缩后图片宽度 * @param {*} height 压缩后图片高度 * @param {*} qua //图片质量1-100 */ function compressImageTobase64(image,width,height,qua){ var quality = qua ? qua / 100 : 0.8; var canvas = document.createElement("canvas"), ctx = canvas.getContext('2d'); var w = image.naturalWidth, h = image.naturalHeight; canvas.width = width||w; canvas.height = height||h; ctx.drawImage(image, 0, 0, w, h, 0, 0, width||w, height||h); var data = canvas.toDataURL("image/jpeg", quality); return data; } //提交 function submit(){ //1、form提交 //document.getElementById("mainForm").submit(); //2、压缩后ajax提交 var face_data=compressImageTobase64(document.getElementById("face-result"),200,100,90); var back_data=compressImageTobase64(document.getElementById("back-result"),200,100,90); var formData = new FormData(); formData.append("face",face_data); formData.append("back",back_data); //需引入jQuery $.ajax({ url:"/地址", type: 'POST', cache: false, data: formData, timeout:180000, processData: false, contentType: false, success:function(r){ }, error:function(r){ } }); }