html2canvas把div儲存圖片高清圖
阿新 • • 發佈:2018-12-23
http://www.bootcdn.cn/(可以搜尋html2canvans)
1.選擇html2canvas版本(這個版本可以放大倍數保證圖片清晰)
- 預設生成的 canvas 圖片在 retina 裝置上顯示很模糊,處理成 2 倍圖能解決這個問題:
var w = $("#code").width();
var h = $("#code").height();
//要將 canvas 的寬高設定成容器寬高的 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");
//然後將畫布縮放,將影象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"); //然後將畫布縮放,將影象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圖片資料 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'); /** * 在本地進行檔案儲存 * @param {String} data 要儲存到本地的圖片資料 * @param {String} filename 檔名 */ 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); }; // 下載後的問題名 var filename = aname+'肌膚檢測報告' + (new Date()).getTime() + '.' + type; // download saveFile(imgData,filename); }, width:1512, height:15000 }) },2500) } else { return; } })