Question

我正在尝试将图像（我的图形的背景图像）与canvasJS图形合并。

在将这些画布合并到画布后，我想获得一个这个画布的DataURL，这将允许我下载它的图像（图形的图像及其各自的背景图像）。

我一直在玩JS Fiddles试图让它工作一段时间，但我似乎无法弄明白。

这是我目前的小提琴：

http://jsfiddle.net/dyt943s0/19/

我通过将其他两个小提琴的代码合并在一起创造了小提琴：

1）https://jsfiddle.net/cuajw85L/1/（合并两个画布并创建它们的图像）。和 2）http://jsfiddle.net/canvasjs/muqb7d3n/（创建CanvasJS图的图像）

以下是我一直在努力的小提琴上的代码：

JS：

var chart = new CanvasJS.Chart("chartContainer",
{
        title: {
            text: "Exporting chart using toDataurl"
        },
        data: [
        {
            type: "spline",
            dataPoints: [ 
                { x: 10, y: 4 }, 
                { x: 20, y: 7 },
                { x: 30, y: 2 },
                { x: 40, y: 3 },
                { x: 50, y: 5 }
            ]
        }
        ]
});

chart.render();

var img=new Image();
img.crossOrigin='anonymous';
img.onload=start;
img.src="https://dl.dropboxusercontent.com/u/139992952/multple/fish.jpg";
function start(){

  var bottleCanvas = document.getElementById('bottleCanvas');
  var designCanvas = $(".canvasjs-chart-canvas");
  var ctxb=bottleCanvas.getContext('2d');
  var ctxd=editorCanvas.getContext('2d');

  ctxb.drawImage(img,0,0);
  ctxd.fillRect(50,50,50,50);

  downloadCanvas();
}

function downloadCanvas() {
  var bottleCanvas = document.getElementById('bottleCanvas');
  var designCanvas = $(".canvasjs-chart-canvas");

  var bottleContext = bottleCanvas.getContext('2d');
  bottleContext.drawImage(designCanvas, 69, 50);

  var dataURL = bottleCanvas.toDataURL("image/png");
  var link = document.getElementById('btn-download');
  link.download = "bottle-design.png";
  link.href = bottleCanvas.toDataURL("image/png").replace("image/png", "image/octet-stream");


}

HTML：

<br/><!-- Just so that JSFiddle's Result label doesn't overlap the Chart -->
<canvas id="bottleCanvas" width=300 height=300></canvas>
<canvas id="editorCanvas" width=300 height=300></canvas>

<div id="chartContainer" style="height: 360px; width: 100%;"></div>
<a href="#" id="btn-download" download="chart.png" target="_blank">Download</a>

Answer 1

想出来！

而不是var designCanvas = $(".canvasjs-chart-canvas");，请使用var designCanvas = $("#chartContainer .canvasjs-chart-canvas").get(0);

http://jsfiddle.net/dyt943s0/21/

如何使用CanvasJS图合并图像并下载它们的图像

1 个答案: