从Canvas Javascript获取图像

Question

I need to get an image from a canvas that is filled with a google map:

  ...

  map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);

  ...

  var canvas = document.getElementById("map-canvas");
  var ctx=canvas.getContext("2d");
  var url = canvas.toDataURL();

Doesn't work. It's broke up at the second line "var ctx=canvas.getContext("2d");" . Can anybody help me? Is there a other way to have the same effect?

Answer 1

You can't do this. Your element map-canvas isn't a canvas element ; it's just an element with an id 'map-canvas'. Canvas methods only work on <canvas> elements.