1.pc端:javascript
<canvas id='canvas' width="500" height="500"></canvas> <!-- <img src="http://gss0.baidu.com/-4o3dSag_xI4khGko9WTAnF6hhy/lvpics/h=800/sign=b49dc48f8718367ab28972dd1e728b68/9922720e0cf3d7ca7f0736d0f31fbe096a63a9a6.jpg" > --> <button id="save">保存</button> <script type="text/javascript"> window.onload = function(){ var canvas = document.getElementById('canvas') var ctx = canvas.getContext('2d') // 內存中先加載,而後當內存加載完畢時,再把內存中的數據填充到咱們的 dom元素中,這樣可以快速的去 // 反應,好比網易的圖片 var img = new Image(); img.setAttribute("crossOrigin",'anonymous');//須要放在圖片賦值前,不然部分瀏覽器會報錯 img.onload = function(){ // alert('加載完畢') // 將圖片畫到canvas上面上去! ctx.drawImage(img,593,327,500,500,100,100,300,300); } img.src = "http://gss0.baidu.com/-4o3dSag_xI4khGko9WTAnF6hhy/lvpics/h=800/sign=b49dc48f8718367ab28972dd1e728b68/9922720e0cf3d7ca7f0736d0f31fbe096a63a9a6.jpg"; // img.src = "http://rc.rry.info/app/index.php?i=1&c=entry&m=ewei_shopv2&do=mobile&r=order.pay.chanPayQrcode&url=https://qr.alipay.com/bax062248bb2tkmy1ubv2071"; } document.getElementById("save").onclick = function (){ console.log('canvas',canvas) downLoad(saveAsJPG(canvas)); } // 保存成png格式的圖片 function saveAsPNG(canvas) { return canvas.toDataURL("image/png"); } // 保存成jpg格式的圖片 function saveAsJPG(canvas) { return canvas.toDataURL("image/jpeg"); } function downLoad(url){ var oA = document.createElement("a"); oA.download = 'img';// 設置下載的文件名,默認是'下載' oA.href = url; document.body.appendChild(oA); oA.click(); oA.remove(); // 下載以後把建立的元素刪除 } </script>
2.移動端:此方法針對多組圖片,多個圖片能夠添加相同的class而後js根據class的長度來進行操做。其中主要用到plus.downloader.createDownload(url, options, completedCB);
php
<img src="H5canvas鼠標通過的地方星星鏈接/xkbg.png" id="image"> <!-- 彈框的html--> <div id="picture" class="mui-popover mui-popover-action mui-popover-bottom" style="z-index: 99999999"> <ul class="mui-table-view"> <li class="mui-table-view-cell"> <a href="javascript:;" id="saveImg">保存圖片</a> </li> </ul> <ul class="mui-table-view"> <li class="mui-table-view-cell"> <a href="#picture"><b>取消</b></a> </li> </ul> </div> <script type="text/javascript"> mui.init( { gestureConfig:{ tap: true, //默認爲true doubletap: true, //默認爲false longtap: true, //默認爲false swipe: true, //默認爲true drag: true, //默認爲true hold:true,//默認爲false,不監聽 release:false//默認爲false,不監聽 }}); document.getElementById('image').onclick = function(){ //給須要長按保存圖片的img標籤設置 class='saveImg' var divs = document.getElementsByClassName('saveImg'); for(var i = 0;i<divs.length;i++){ divs[i].addEventListener('longtap', function () { //開啓彈框 mui('#picture').popover('toggle'); console.log(this.src) var imgurl = this.src; document.getElementById('saveImg').addEventListener('tap', function () { var imgDtask = plus.downloader.createDownload(imgurl,{method:'GET'}, function (d,status) { if(status == 200){ plus.gallery.save(d.filename, function () {//保存到相冊 plus.io.resolveLocalFileSystemURL(d.filename, function (enpty) { // 關閉彈框 mui('#picture').popover('toggle'); mui.toast('保存成功') }); }) }else{ mui.toast('保存失敗') } }); imgDtask.start(); }); }) } } </script>
3.移動端單張圖片:注意plus.downloader.createDownload(url, options, completedCB)
中的url是圖片在服務器端的路徑好比:https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=1335795923,3245280170&fm=15&gp=0.jpg這種格式,而不是文件資源!css
<script src="js/mui.min.js"></script> <link href="css/mui.min.css" rel="stylesheet"/> <script src="js/jquery-2.js" type="text/javascript" charset="utf-8"></script> <script type="text/javascript" charset="utf-8"> mui.init(); </script> <style type="text/css"> #imageList{ display: flex; } .cs{ width: 0; height: 0; } .saveImg1{ width: 100%; height: 100%; visibility: hidden; } </style> </head> <body> <!-- <img id="image" style="width: 300px;height: 300px;" src="https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1571203612306&di=42932c7868bcb8054af73d53d0b24ff6&imgtype=0&src=http%3A%2F%2Fhbimg.b0.upaiyun.com%2F28ea2e5cf17173f84ef74064e95627cc3ba75fe627e71-hKNgS4_fw658" > --> <div class="imageList"> <div id=""> <canvas id='canvas' width="300" height="300"></canvas> </div> <div class="cs"> <img class="saveImg1" style="width: 200px;height: 200px;" src="https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=1335795923,3245280170&fm=15&gp=0.jpg" > </div> <div id="image"> 保存 </div> </div> <!-- 彈框的html--> <div id="picture" class="mui-popover mui-popover-action mui-popover-bottom" style="z-index: 99999999"> <ul class="mui-table-view"> <li class="mui-table-view-cell"> <a href="javascript:;" id="saveImg">保存圖片</a> </li> </ul> <ul class="mui-table-view"> <li class="mui-table-view-cell"> <a href="#picture"><b>取消</b></a> </li> </ul> </div> <script type="text/javascript"> mui.init( { gestureConfig:{ tap: true, //默認爲true doubletap: true, //默認爲false longtap: true, //默認爲false swipe: true, //默認爲true drag: true, //默認爲true hold:true,//默認爲false,不監聽 release:false//默認爲false,不監聽 }}); window.onload = function(){ var canvas = document.getElementById('canvas') var ctx = canvas.getContext('2d') // 內存中先加載,而後當內存加載完畢時,再把內存中的數據填充到咱們的 dom元素中,這樣可以快速的去 // 反應,好比網易的圖片 var img = new Image(); img.setAttribute("crossOrigin",'anonymous');//須要放在圖片賦值前,不然部分瀏覽器會報錯 img.onload = function(){ // 將圖片畫到canvas上面上去! ctx.drawImage(img,593,327,500,500,100,100,300,300); } img.src = "http://gss0.baidu.com/-4o3dSag_xI4khGko9WTAnF6hhy/lvpics/h=800/sign=b49dc48f8718367ab28972dd1e728b68/9922720e0cf3d7ca7f0736d0f31fbe096a63a9a6.jpg"; // img.src = "http://rc.rry.info/app/index.php?i=1&c=entry&m=ewei_shopv2&do=mobile&r=order.pay.chanPayQrcode&url=https://qr.alipay.com/bax062248bb2tkmy1ubv2071"; $('.saveImg1').attr('src',img.src) } // document.getElementById('image').addEventListener('tap',function(){ console.log('點擊圖片了') //給須要長按保存圖片的img標籤設置 class='saveImg' var divs = $('.saveImg1'); $('#canvas')[0].addEventListener('longtap', function () { //開啓彈框 mui('#picture').popover('toggle'); var imgurl = divs[0].src; document.getElementById('saveImg').addEventListener('tap', function () { var imgDtask = plus.downloader.createDownload(imgurl,{method:'GET'}, function (d,status) { console.log(typeof(imgurl)) console.log(imgurl) console.log(JSON.stringify(d)) console.log(JSON.stringify(status)) if(status == 200){ plus.gallery.save(d.filename, function () {//保存到相冊 plus.io.resolveLocalFileSystemURL(d.filename, function (enpty) { // 關閉彈框 mui('#picture').popover('toggle'); mui.toast('保存成功') }); }) }else{ mui.toast('保存失敗') } }); imgDtask.start(); }); }) </script>
4.本身用canvas畫圖並下載html
<div id="app"></div> <canvas id="canvas" width="400" height="400"></canvas> <div> <button id="save">保存</button> </div> </body> <script> var arr = [ {locations:[[0,0],[200,200],[0,400]],color:"red"}, {locations:[[0,0],[400,0],[200,200]],color:"orange"}, {locations:[[0,400],[100,300],[200,400]],color:"yellow"}, {locations:[[100,300],[200,200],[300,300],[200,400]],color:"green"}, {locations:[[300,100],[200,200],[300,300]],color:"blue"}, {locations:[[300,100],[400,0],[400,200],[300,300]],color:"indigo"}, {locations:[[200,400],[400,400],[400,200]],color:"purple"} ]; var oCanvas = document.getElementById("canvas"); var ctx = oCanvas.getContext("2d"); for(let i=0;i<arr.length;i++){ draw(arr[i],ctx); } function draw(item,ctx){ ctx.beginPath(); ctx.moveTo(item.locations[0][0],item.locations[0][1]); for(let i = 0;i<item.locations.length;i++){ let x = item.locations[i][0]; let y = item.locations[i][1]; ctx.lineTo(x,y); console.log(1234567) } ctx.closePath(); ctx.fillStyle = item.color; ctx.fill(); ctx.strokeStyle = "#000"; ctx.lineWidth = 2; ctx.stroke(); } var imgId = document.getElementById("imgId"); document.getElementById("save").onclick = function (){ console.log('canvas',canvas) downLoad(saveAsPNG(canvas)); } // 保存成png格式的圖片 function saveAsPNG(canvas) { return canvas.toDataURL("image/png"); } // 保存成jpg格式的圖片 function saveAsJPG(canvas) { return canvas.toDataURL("image/jpeg"); } // 保存成bmp格式的圖片 目前瀏覽器支持性很差 function saveAsBMP(canvas) { return canvas.toDataURL("image/bmp"); } /** * @author web得勝 * @param {String} url 須要下載的文件地址 * */ function downLoad(url){ var oA = document.createElement("a"); oA.download = 'img';// 設置下載的文件名,默認是'下載' oA.href = url; document.body.appendChild(oA); console.log(oA) oA.click(); oA.remove(); // 下載以後把建立的元素刪除 } </script>