HTML5 Draggable setDragImage 不适用于 Chrome 上的画布

我正在尝试在原生 HTML5 Drag And Drop API 中使用画布作为我的拖动图像.

I'm trying to use canvas as my drag image in native HTML5 Drag And Drop API.

问题是它可以在 Firefox 上运行,但不能在 Chrome (58) 上运行,我无法确定问题所在.

The problem is that it works on Firefox but not on Chrome (58) and I can't pinpoint the problem.

代码:https://jsfiddle.net/196urLwd/5/

<div id="thing" draggable="true">DRAG ME</div>

<小时>

function onDragStart(event){

    var canvas = document.createElement('canvas');
    var context = canvas.getContext('2d');

    canvas.width = 100;
    canvas.height = 20;

    context.fillStyle = '#333333';
    context.fillRect(0, 0, canvas.width, canvas.height);

    context.fillStyle = '#999999';
    context.font = 'bold 13px Arial';
    context.fillText('DRAGGING...', 5, 15);

    event.dataTransfer.setData('text', 'lorem ipsum');
    event.dataTransfer.effectAllowed = 'copy';    
    event.dataTransfer.setDragImage(canvas, -15, 9);

};

var theThing = document.getElementById('thing');
theThing.addEventListener('dragstart', onDragStart, false);

我做错了什么?

推荐答案

Chrome好像要求canvas在dom中

Chrome seems to require the canvas to be in the dom

document.body.append(canvas);

然后用一些 css 隐藏它

and just hide it with some css

canvas{
  position:absolute;
  left:-100%;
}

https://jsfiddle.net/196urLwd/6/

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