0

我正在处理需要将谷歌图表导出为 JPEG/PNG 图像的要求。以下代码在除 Internet Explorer 之外的其他浏览器中运行良好。

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

<script type="text/javascript" src="http://canvg.googlecode.com/svn/trunk/rgbcolor.js"></script>
<script type="text/javascript" src="http://canvg.googlecode.com/svn/trunk/canvg.js"></script>
<script>
function getImgData(chartContainer) {
var chartArea = chartContainer.getElementsByTagName('svg')[0].parentNode;
var svg = chartContainer.getElementsByTagName('svg')[0].innerHTML ;
var doc = chartContainer.ownerDocument;
var canvas = doc.createElement('canvas');
canvas.setAttribute('width', chartArea.offsetWidth);
canvas.setAttribute('height', chartArea.offsetHeight);


canvas.setAttribute(
'style',
'position: absolute; ' +
'top: ' + (-chartArea.offsetHeight * 2) + 'px;' +
'left: ' + (-chartArea.offsetWidth * 2) + 'px;');
doc.body.appendChild(canvas);
canvg(canvas, svg);

 var imgData=canvas.toDataURL("image/png");

canvas.parentNode.removeChild(canvas);
return imgData;
}

function saveAsImg(chartContainer) {
var imgData = getImgData(chartContainer);
window.location.href = imgData.replace("image/png", "image/octet-stream");
}

function toImg(chartContainer, imgContainer) {
var doc = chartContainer.ownerDocument;
var img = doc.createElement('img');
img.src = getImgData(chartContainer);
while (imgContainer.firstChild) {
imgContainer.removeChild(imgContainer.firstChild);
}
imgContainer.appendChild(img);
}
</script>
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load("visualization", "1", {packages:["corechart", "treemap", "geochart"]});
google.setOnLoadCallback(drawChart);
function drawChart() {
// Pie chart
var data = new google.visualization.DataTable();
data.addColumn('string', 'Task');
data.addColumn('number', 'Hours per Day');
data.addRows(5);
data.setValue(0, 0, 'Work');
data.setValue(0, 1, 11);
data.setValue(1, 0, 'Eat');
data.setValue(1, 1, 2);
data.setValue(2, 0, 'Commute');
data.setValue(2, 1, 2);
data.setValue(3, 0, 'Watch TV');
data.setValue(3, 1, 2);
data.setValue(4, 0, 'Sleep');
data.setValue(4, 1, 7);

var chart = new google.visualization.PieChart(document.getElementById('pie_div'));
chart.draw(data, {width: 450, height: 300, title: 'My Daily Activities'});
// Line chart
data = new google.visualization.DataTable();
data.addColumn('string', 'Year');
data.addColumn('number', 'Sales');
data.addColumn('number', 'Expenses');
data.addRows(4);
data.setValue(0, 0, '2004');
data.setValue(0, 1, 1000);
data.setValue(0, 2, 400);
data.setValue(1, 0, '2005');
data.setValue(1, 1, 1170);
data.setValue(1, 2, 460);
data.setValue(2, 0, '2006');
data.setValue(2, 1, 860);
data.setValue(2, 2, 580);
data.setValue(3, 0, '2007');
data.setValue(3, 1, 1030);
data.setValue(3, 2, 540);

var chart = new google.visualization.LineChart(document.getElementById('line_div'));
chart.draw(data, {width: 450, height: 300, title: 'Company Performance'});
// Treemap
data = new google.visualization.DataTable();
data.addColumn('string', 'Region');
data.addColumn('string', 'Parent');
data.addColumn('number', 'Market trade volume (size)');
data.addColumn('number', 'Market increase/decrease (color)');
data.addRows([
["Global",null,0,0],
["America","Global",0,0],
["Europe","Global",0,0],
["Asia","Global",0,0],
["Australia","Global",0,0],
["Africa","Global",0,0],
["Brazil","America",11,10],
["USA","America",52,31],
["Mexico","America",24,12],
["Canada","America",16,-23],
["France","Europe",42,-11],
["Germany","Europe",31,-2],
["Sweden","Europe",22,-13],
["Italy","Europe",17,4],
["UK","Europe",21,-5],
["China","Asia",36,4],
["Japan","Asia",20,-12],
["India","Asia",40,63],
["Laos","Asia",4,34],
["Mongolia","Asia",1,-5],
["Israel","Asia",12,24],
["Iran","Asia",18,13],
["Pakistan","Asia",11,-52],
["Egypt","Africa",21,0],
["S. Africa","Africa",30,43],
["Sudan","Africa",12,2],
["Congo","Africa",10,12],
["Zair","Africa",8,10]
]);

var tree = new google.visualization.TreeMap(document.getElementById('treemap_div'));
tree.draw(data, {
minColor: '#f00',
midColor: '#ddd',
maxColor: '#0d0',
headerHeight: 15,
fontColor: 'black',
showScale: true});
data = new google.visualization.DataTable();
data.addRows(6);
data.addColumn('string', 'Country');
data.addColumn('number', 'Popularity');
data.setValue(0, 0, 'Germany');
data.setValue(0, 1, 200);
data.setValue(1, 0, 'United States');
data.setValue(1, 1, 300);
data.setValue(2, 0, 'Brazil');
data.setValue(2, 1, 400);
data.setValue(3, 0, 'Canada');
data.setValue(3, 1, 500);
data.setValue(4, 0, 'France');
data.setValue(4, 1, 600);
data.setValue(5, 0, 'RU');
data.setValue(5, 1, 700);

var options = {};
var container = document.getElementById('map_div');
var geochart = new google.visualization.GeoChart(container);
geochart.draw(data, options);
data = new google.visualization.DataTable();
data.addColumn('number', 'Age');
data.addColumn('number', 'Weight');
data.addRows(6);
data.setValue(0, 0, 8);
data.setValue(0, 1, 12);
data.setValue(1, 0, 4);
data.setValue(1, 1, 5.5);
data.setValue(2, 0, 11);
data.setValue(2, 1, 14);
data.setValue(3, 0, 4);
data.setValue(3, 1, 4.5);
data.setValue(4, 0, 3);
data.setValue(4, 1, 3.5);
data.setValue(5, 0, 6.5);
data.setValue(5, 1, 7);

var chart = new google.visualization.ScatterChart(document.getElementById('scatter_div'));
chart.draw(data, {width: 400, height: 240,
title: 'Age vs. Weight comparison',
hAxis: {title: 'Age', minValue: 0, maxValue: 15},
vAxis: {title: 'Weight', minValue: 0, maxValue: 15},
legend: 'none'
});
}
</script>
</head>
<body>
<div id="img_div" style="position: fixed; top: 0; right: 0; z-index: 10; border: 1px solid #b9b9b9">
Image will be placed here
</div>

<button onclick="saveAsImg(document.getElementById('pie_div'));">Save as PNG Image</button>
<button onclick="toImg(document.getElementById('pie_div'), document.getElementById('img_div'));">Convert to image</button>
<div id="pie_div"></div>

<button onclick="saveAsImg(document.getElementById('line_div'));">Save as PNG Image</button>
<button onclick="toImg(document.getElementById('line_div'), document.getElementById('img_div'));">Convert to image</button>
<div id="line_div"></div>
<button onclick="saveAsImg(document.getElementById('treemap_div'));">Save as PNG Image</button>
<button onclick="toImg(document.getElementById('treemap_div'), document.getElementById('img_div'));">Convert to image</button>
<div id="treemap_div" style="width: 450px; height: 300px;"></div>

<button onclick="saveAsImg(document.getElementById('map_div'));">Save as PNG Image</button>
<button onclick="toImg(document.getElementById('map_div'), document.getElementById('img_div'));">Convert to image</button>
<div id="map_div" style="width: 500px; height: 300px"></div>
<button onclick="saveAsImg(document.getElementById('scatter_div'));">Save as PNG Image</button>
<button onclick="toImg(document.getElementById('scatter_div'), document.getElementById('img_div'));">Convert to image</button>
<div id="scatter_div"></div>
</body>
</html>

在 IE 10 中运行上述代码时，它显示空白 PNG 图像，我发现此行有任何问题

canvas.toDataURL("图片/png");

请对此进行调查并提供解决方案

4

1 回答 1

0

我正在使用相同的代码，不得不更改一行：

从：var svg = chartContainer.getElementsByTagName('svg')[0].innerHTML ;

至：var svg = '<svg>' + chartContainer.getElementsByTagName('svg')[0].innerHTML + '</svg>'

我在这里的评论中发现： https ://gist.github.com/battlehorse/1333906

于 2016-09-26T18:47:02.560 回答