效果圖:
SVG格式圖片經過一系列轉換變成PNG格式的圖片並下載
HTML代碼:
<style>
.JBS {
background-image: linear-gradient(-225deg,#4076FF 0%,#DE4AFF 100%,#61D2FF 100%);
width: 100%;
height: 200px
}
</style>
<h2>Input Div:</h2>
<div id="div" class="JBS"></div>
<h2>Output Image:</h2>
JavaScript代碼 :
<script>
//1.將div轉成svg
var data = "data:image/svg+xml," +
"<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'>" +
"<foreignObject width='100%' height='100%'>" +
"<div xmlns='http://www.w3.org/1999/xhtml' style='background-image: linear-gradient(-225deg,#4076FF 0%,#DE4AFF 100%,#61D2FF 100%);width:100%;height:200px'> </div>" +
"</foreignObject>" +
"</svg>";
var img = new Image();
img.src = data;
document.getElementsByTagName('body')[0].appendChild(img);
//2.svg轉成canvas
var canvas = document.createElement('canvas'); //準備空畫布
canvas.width = img.width;
canvas.height = img.height;
var context = canvas.getContext('2d'); //取得畫布的2d繪圖上下文
context.drawImage(img, 0, 0);
var a = document.createElement('a');
a.href = canvas.toDataURL('image/png'); //將畫布內的信息導出爲png圖片數據
a.download = "MapByMathArtSys"; //設定下載名稱
//3. 圖片導出爲 png 格式
var type = 'png';
var imgData = canvas.toDataURL(type);
/**
* 獲取mimeType
* @param {String} type the old mime-type
* @return the new mime-type
*/
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');
/**
* 在本地進行文件保存
* @param {String} data 要保存到本地的圖片數據
* @param {String} filename 文件名
*/
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);
};
// 下載後的圖片名
var filename = 'LoveCrystal_' + (new Date()).getTime() + '.' + type;
// download
saveFile(imgData, filename);
</script>