使用html2canvas js 截取網頁圖片下載

時間 2020-05-25

標籤使用 html2canvas html canvas 截取網頁圖片下載欄目 HTML 简体版

原文原文鏈接

1.前臺使用html2canvas js 截取Div元素轉存爲圖片，下載。效果：javascript

2.前臺代碼html

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title></title>
   <meta charset="utf-8" />
    <script src="Html2canvas_JS/html2canvas.min.js"></script>
    <script src="Html2canvas_JS/canvas2image.js"></script>
</head>
<body>
<div id="div1" style="width: 200px; height: 450px; border: silver 1px solid; ">
    <img src="Images/imgDemo.jpg" style="width: 160px; height: 160px; margin-left: 20px; margin-right: 20px; margin-top: 40px;"/>
    <label style="text-align: center;display:block"><b>王二小</b><br/></label>
    <label style="text-align: center;display:block">王二小喜歡放牛<br/></label>
    <div align="center">
        王二小喜歡放牛,<br />
        王二小喜歡放牛,<br />
        王二小喜歡放牛,<br />
        王二小喜歡放牛 <br />
    </div>
</div>java

<div id="img" style="display: none; width: 200px; height: 450px; position: absolute; top: 8px; left: 216px;"></div>
<button id="btnCreateImg">生成圖片</button>
<button id="btnSaveImg">下載圖片</button>
</body>
<script type="text/javascript">
    var content = document.getElementById("div1");
    var btn = document.getElementById("btnCreateImg");
    btn.onclick = function() {
        html2canvas(content, {
            useCORS: true, //容許跨域
            onrendered:function(canvas) {
                canvas.setAttribute("id", "thecanvas");
                document.getElementById("img").innerHTML = "";
                document.getElementById("img").appendChild(canvas);
            }
        });
        window.alert('生成圖片成功');
    };

    var btnDownload = document.getElementById("btnSaveImg");
    btnDownload.onclick = function () {
        var timestamp = Date.parse(new Date());
        var fileName = timestamp + ".PNG";

        var oCanvas = document.getElementById("thecanvas");
        var img_data1 = Canvas2Image.saveAsPNG(oCanvas, true).getAttribute("src");

        //下載保存
        saveFile(img_data1, fileName);

        //此種方法將直接下載文件，可是不帶有圖片後綴名
        //Canvas2Image.saveAsPNG(oCanvas);

        window.alert('下載完成');
    };

    var saveFile = function (data, fileName) {
        var link = document.createElement('a');
        link.href = data;
        link.download = fileName;
        link.title = "";

        var event = document.createEvent("MouseEvents");
        event.initEvent("click", true, true);
        link.dispatchEvent(event);
    };
</script>
</html>canvas