在angular 2中下载画布图像

<canvas #canvas></canvas>
<button (click)="downloadCanvas()">下载画布图像</button>

import { Component, ViewChild, ElementRef } from '@angular/core';

@ViewChild('canvas', { static: true }) canvas: ElementRef<HTMLCanvasElement>;

downloadCanvas() {
  const canvas = this.canvas.nativeElement;
  const image = canvas.toDataURL("image/png").replace("image/png", "image/octet-stream");
  const link = document.createElement('a');
  link.href = image;
  link.download = 'canvas-image.png';
  link.click();
}