使用html2canvas將頁面轉成圖，用canvas2image下載

以前在網上找到一個用 <a> 的 download屬性下載的方法，確實很簡單也很方便，但此方法不支持IE，無奈又找到另外一方法。

使用html2canvas將頁面轉成圖，用canvas2image下載

本例使用的版本：

html2canvas@1.0.0-alpha.12
canvas2image@1.0.5

安裝

npm install html2canvas canvas2image --save

引入

import html2canvas from 'html2canvas';
require('./canvas2image.js');

canvas2image.js 須要改動一下，以便綁在window上

(function($){
    Canvas2Image = function () {
    ...
    }
}

_dataURL 能夠用來回顯，Canvas2Image.saveAsPNG(canvas) 會直接下載。
Canvas2Image提供了下面幾種方法:

Canvas2Image.saveAsImage(canvasObj, width, height, type)
Canvas2Image.saveAsPNG(canvasObj, width, height)
Canvas2Image.saveAsJPEG(canvasObj, width, height)
Canvas2Image.saveAsGIF(canvasObj, width, height)
Canvas2Image.saveAsBMP(canvasObj, width, height)

Canvas2Image.convertToImage(canvasObj, width, height, type)
Canvas2Image.convertToPNG(canvasObj, width, height)
Canvas2Image.convertToJPEG(canvasObj, width, height)
Canvas2Image.convertToGIF(canvasObj, width, height)
Canvas2Image.convertToBMP(canvasObj, width, height)

在vue中能夠用$refs 肯定DOM；
backgroundColor: null，此句可以使轉出的圖沒有白邊

methods: {
            toImage() {
                let _this = this;
                html2canvas(this.$refs.index,{
                    backgroundColor: null
                }).then((canvas) => {
                    let _dataURL = canvas.toDataURL("image/png");                    
                    // _this.dataURL = _dataURL;
                    Canvas2Image.saveAsPNG(canvas)
                });
            },