Question

我正在使用html2canvas从我的html页面生成图像。

当我输入我的网址时 http://prompter.rareapps.org/prompt/prompt-save2.php?p=123

在html2canvas网站（http://html2canvas.hertzen.com/screenshots.html）的网页渲染器中，我的页面以背景形式呈现。

但是当我生成自己的画布时，我没有背景。这是我的代码

<script type="text/javascript">
$( document ).ready(function() {
    html2canvas(document.body, {
        allowTaint: true,
        taintTest: false,
        onrendered: function(canvas) {
        window.location.href = canvas.toDataURL('image/jpeg');
      }
    });
});

我错过了什么？

由于

Answer 1

此问题已在0.5.0版本中修复（但版本0.5.0尚未准备好使用）。

但是有许多问题需要纠正，而基本功能尚未实施。

注意：html2canvas没有0.5.0版本的日期预测注意：版本0.4.1不再接收更新

问题是版本0.5.0还没有准备好使用，我重新编写你的html，请参阅：

<!DOCTYPE html><!--// Never put a space/break-line before the DOCTYPE -->
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <meta charset="UTF-8">

    <script type="text/javascript" src="html2canvas.js"></script>
    <script type="text/javascript" src="https://code.jquery.com/jquery-1.11.0.min.js"></script>

    <style type="text/css">
        html, body {
            margin: 0;
            padding: 0;
            height: 100%;
        }
        body {
            font-family: Georgia, serif;
            font-size: 4em;
        }
        p {
            padding: 5px 0;
            margin: 0;
        }

        #main {
            margin: 0 auto;
            width: 100%;
            min-height: 100%;
            font-weight: bold;
            background: white url('prompt-save-bg.jpg') center top repeat-y;
            max-width: 1263px; /* background-limit*/
            text-align: center;
        }
        #article {
            padding: 5em 2em 0 2em;
            font-weight: bold;
        }
        #article p.info {
            font-size: 0.2em; padding: 40em 0;
        }
    </style>

    <script type="text/javascript">
    //<!CDATA[
    function save(canvas) {/*html2canvas-0.5.0 work with Promise.js*/
        window.open(canvas.toDataURL());
    }
    $(document).ready(function(){
        $('#save-image').click(function () {
            html2canvas(document.body, {
                allowTaint: true,
                logging: true,
                taintTest: false,
                onrendered: save /*0.4.1*/
            }).then(save);/*0.5.0-rc*/
        });
    });
    //]]>
    </script>
</head>
<body>
    <div id="main">
        <input value="Generate Image" id="save-image" download="YourFileName.jpg" type="button">

        <div id="article">
            <h2>AUBREY</h2>

            <p>And Aubrey was her name</p>
            <p>A not so very ordinary girl or name</p>
            <p>But who's to blame?</p>
            <p>For a love that wouldn't bloom</p>
            <p>For the hearts that never played in tune</p>
            <p>Like a lovely melody that everyone can sing</p>
            <p>Take away the words that rhyme, it doesn't mean a thing</p>
            <p>&nbsp;</p>
            <p>And Aubrey was her name</p>
            <p>We tripped the light and danced together to the moon</p>
            <p>But where was June?</p>
            <p>No, it never came around</p>
            <p>If it did it never made a sound</p>
            <p>Maybe I was absent or was listening too fast</p>
            <p>Catching all the words but then the meaning going past</p>
            <p>&nbsp;</p>
            <p>But God I miss the girl</p>
            <p>And I'd go a thousand times around the world just to be</p>
            <p>Closer to her than to me</p>
            <p>&nbsp;</p>
            <p>And Aubrey was her name</p>
            <p>I never knew her but I loved her just the same</p>
            <p>I loved her name</p>
            <p>Wish that I had found the way</p>
            <p>And the reasons that would make her stay</p>
            <p>I have learned to lead a life apart from all the rest</p>
            <p>If I can't have the one I want, I'll do without the best</p>
            <p>&nbsp;</p>
            <p>But how I miss the girl</p>
            <p>And I'd go a million times around the world just to say</p>
            <p>She had been mine for a day</p>

            <p class="info">
                Prompter generated by RAREAPPS: http://prompter.rareapps.org
            </p>
        </div>
    </div>
</body>
</html>

曾在0.4.1和0.5.0-rc工作。
使用Chrome和Firefox。

请注意，我创建了一个名为save()的函数，因此您可以在onrendered（版本0.4.1）或then（版本0.5.0-rc）之间切换。

我把你的背景和<DIV>改为<html>而不是<body>，因为＆＃34; html2canvas＆＃34;是不够聪明，无法理解窗口中overflow:的操作。

请注意，上一段（margin:;）中的<p>会导致＆＃34; html2canvas＆＃34;如同＃34; Webkit＆＃34;浏览器所以我使用了padding:

请记住，做同样事情的方法不止一种。

Answer 2

明确设置背景样式例如。如果

...
 html2canvas(document.body,
        {
            onrendered: function(canvas){
                 var imgData = canvas.toDataURL("image/jpeg");
                var doc = new jsPDF('p','mm');
                doc.addImage(imgData, 'JPEG', 15, 40, 180, 160);
                doc.save($.now()+'.pdf');
        }

pdf有空白（黑色）背景，

现在如果添加CSS样式

 body {
         background-color: white;
     }

空白（黑色）背景已更正

Answer 3

背景图片的背景图片属性在0.4.1版本中设置为封面时出现问题，这是当前可用的最新版本。

＆＃39; fperich＆＃39;提供的解决方案在这个页面解决了我的问题： https://github.com/niklasvh/html2canvas/issues/265

根据他的解决方案，只需使用以下语句更新版本0.4.1中的第350行：

topPos = isNaN(parseInt(bgposition[1], 10)) ? topPos : parseInt(bgposition[1], 10);

html2canvas缺少背景

3 个答案: