在尝试使用 KineticJS (v4.5.4) 创建自定义形状时,我注意到 Kinetic.Shape 类 drawFunc 方法被调用了两次,比我预期的要多一次,因为下面的代码(改编自 http://www.html5canvastutorials .com/kineticjs/html5-canvas-kineticjs-shape-tutorial/)。当我运行下面的代码时,我可以看到在我的浏览器控制台上打印了两次“DEBUG”,表明有问题的方法被调用了两次,这是为什么呢?
<!DOCTYPE HTML>
<html>
<head>
<style>
body {
margin: 0px;
padding: 0px;
}
</style>
</head>
<body>
<div id="container"></div>
<script src="http://d3lp1msu2r81bx.cloudfront.net/kjs/js/lib/kinetic-v4.5.4.min.js"></script>
<script defer="defer">
var stage = new Kinetic.Stage({
container: 'container',
width: 578,
height: 200
});
var layer = new Kinetic.Layer();
/*
* create a triangle shape by defining a
* drawing function which draws a triangle
*/
var triangle = new Kinetic.Shape({
drawFunc: function(canvas) {
console.log('DEBUG');
var context = canvas.getContext();
context.beginPath();
context.moveTo(200, 50);
context.lineTo(420, 80);
context.quadraticCurveTo(300, 100, 260, 170);
context.closePath();
canvas.fillStroke(this);
},
fill: '#00D2FF',
stroke: 'black',
strokeWidth: 4
});
// add the triangle shape to the layer
layer.add(triangle);
// add the layer to the stage
stage.add(layer);
</script>
</body>
</html>
干杯