Javascript Fabric.js-如何为画布加载的事件提供回调
我从JSON对象加载画布并调用toDataURL,但我需要一个回调,该回调将在加载画布后执行,因为如果画布上有图像,toDataURL函数将返回一个空白页,因为它是在加载图像之前调用的Javascript Fabric.js-如何为画布加载的事件提供回调,javascript,html,canvas,html5-canvas,fabricjs,Javascript,Html,Canvas,Html5 Canvas,Fabricjs,我从JSON对象加载画布并调用toDataURL,但我需要一个回调,该回调将在加载画布后执行,因为如果画布上有图像,toDataURL函数将返回一个空白页,因为它是在加载图像之前调用的 canvas.loadFromJSON(json); // I need an event handler here which will be executed after canvas is loaded var dataURL = canvas.toDataURL(); <pre>
canvas.loadFromJSON(json);
// I need an event handler here which will be executed after canvas is loaded
var dataURL = canvas.toDataURL();
<pre>
canvas.loadFromJSON(url, function () {
//first render
canvas.renderAll.bind(canvas);
//before call to zoomOut();
zoomOut();
});
function zoomOut() {
var objects = canvas.getObjects();
console.debug(objects);
......
}
您可以使用loadFromJSONurl的回调,callback
阅读手册!我认为这个问题应该链接到:如果图像来自远程源,fabric似乎不会等待它们被下载。