/**
* 根据图片生成画布
*/
function convertImageToCanvas(image) {
var canvas = document.createElement("canvas");
canvas.width = image.width;
canvas.height = image.height;
canvas.getContext("2d").drawImage(image, 0, 0); //把图片画到画布上
return canvas;
}
原始的image怎么来的？ 功能就是把图片变成画布 那么图片从哪里来？
代码只有一个image的形参而已啊
以下是完整代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=Edge,chrome=1">
<meta name="viewport"
content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
<title>场景出图</title>
<link href="Build/Cesium/Widgets/widgets.css" rel="stylesheet">
<link href="css/pretty.css" rel="stylesheet">
<script src="js/jquery.min.js"></script>
<script src="js/config.js"></script>
<script type="text/javascript" src="Build/Cesium/Cesium.js"></script>
</head>
<body>
<div id="cesiumContainer"></div>
<div id='tool' style="position: absolute;left: 5px;top: 5px;">
<div>
<input type="button" id="custom" value="场景出图" class="button black">
</div>
</div>
<script type="text/javascript">
function onload(Cesium) {
var viewer = new Cesium.Viewer('cesiumContainer');
viewer.imageryLayers.addImageryProvider(new Cesium.BingMapsImageryProvider({
url: '
https://dev.virtualearth.net',
mapStyle: Cesium.BingMapsStyle.AERIAL,
key: URL_CONFIG.BING_MAP_KEY
}));
var scene = viewer.scene;
var promise = scene.open(URL_CONFIG.SCENE_NIAOCHAO);
$("#custom").on("click", function () {
var promise = scene.outputSceneToFile();
Cesium.when(promise, function (base64data) {
download(base64data);
})
})
}
/**
* 根据图片生成画布
*/
function convertImageToCanvas(image) {
var canvas = document.createElement("canvas");
canvas.width = image.width;
canvas.height = image.height;
canvas.getContext("2d").drawImage(image, 0, 0); //把图片画到画布上
return canvas;
}
/**
* 下载图片
*/
function download(base64data) {
var image = new Image();
image.src = base64data;
image.onload = function() {
var canvas = convertImageToCanvas(image);
url = canvas.toDataURL("image/jpeg");
var a = document.createElement('a');
var event = new MouseEvent('click');
a.download = (new Date()).getTime() + ".jpg"; // 指定下载图片的名称
a.href = url;
a.dispatchEvent(event); // 触发超链接的点击事件
}
}
onload(Cesium);
</script>
</body>
</html>
