默認生成的 canvas 圖片在 retina 設備上顯示很模糊,處理成 2 倍圖能解決這個問題:
var w = $( #code ).width();var h = $( #code ).height();//要將 canvas 的寬高設置成容器寬高的 2 倍var canvas = document.createElement( canvas canvas.width = w * 2;canvas.height = h * 2;canvas.style.width = w + px canvas.style.height = h + px var context = canvas.getContext( 2d //然后將畫布縮放,將圖像放大兩倍畫到畫布上context.scale(2,2);html2canvas(document.querySelector( #code ), { canvas: canvas, onrendered: function(canvas) {});
下載方法:
.on( click , .download ,function(){ $( #mycanvas ).remove(); var _height=$( .skinReport ).height(); //滾到頂部 $( html, body ).animate({scrollTop:0}); if(confirm( 是否下載肌膚檢測報告? )) setTimeout(function(){ var canvas = document.createElement( canvas ), w=$( #skinReport ).width(), h=$( #skinReport ).height(); canvas.width = w * 2; canvas.height = h * 2; canvas.style.width = w + px canvas.style.height = h + px var context = canvas.getContext( 2d //然后將畫布縮放,將圖像放大兩倍畫到畫布上 context.scale(2,2); html2canvas(document.getElementById( skinReport ), { allowTaint: false, taintTest: true, canvas: canvas, onrendered: function(canvas) { canvas.id = mycanvas canvas.style.display = none document.body.appendChild(canvas); //生成base64圖片數據 imgData = canvas.toDataURL(type); //var newImg = document.createElement( img //newImg.src = dataUrl; //document.body.appendChild(newImg); //console.log(imgData); var _fixType = function(type) { type = type.toLowerCase().replace(/jpg/i, jpeg var r = type.match(/png|jpeg|bmp|gif/)[0]; return image/ + r; // 加工image data,替換mime type imgData = imgData.replace(_fixType(type), image/octet-stream * 在本地進行文件保存 * @param {String} data 要保存到本地的圖片數據 * @param {String} filename 文件名 var saveFile = function(data, filename){ var save_link = document.createElementNS( http://www.w3.org/1999/xhtml , a save_link.href = data; save_link.download = filename; var event = document.createEvent( MouseEvents event.initMouseEvent( click , true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null); save_link.dispatchEvent(event); // 下載后的問題名 var filename = aname+ 肌膚檢測報告 + (new Date()).getTime() + . + type; // download saveFile(imgData,filename); width:1512, height:15000 },2500) else return; })上面是我整理給大家的,希望今后會對大家有幫助。
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以上就是html2canvas把div保存圖片高清圖(圖文教程)的詳細內容,html教程
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