CanvasRenderingContext2D
.shadowOffsetX
是 Canvas 2D API 描述阴影水平偏移距离的属性。
Syntax
ctx.shadowOffsetX = offset;
示例
使用 shadowOffsetX
属性
这是一段简单的代码片段,使用 shadowOffsetX
属性设置阴影的水平偏移量。注意:将shadowColor属性设置成不透明,阴影才会被绘制。
HTML
<canvas id="canvas"></canvas>
JavaScript
var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); ctx.shadowColor = "black"; ctx.shadowOffsetX = 10; ctx.shadowBlur = 10; ctx.fillStyle = "green"; ctx.fillRect(10, 10, 100, 100);
修改下面的代码并在线查看 canvas 的变化:
Playable code
<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas> <div class="playable-buttons"> <input id="edit" type="button" value="Edit" /> <input id="reset" type="button" value="Reset" /> </div> <textarea id="code" class="playable-code"> ctx.shadowColor = "black"; ctx.shadowOffsetX = 10; ctx.shadowBlur = 10; ctx.fillStyle = "green"; ctx.fillRect(10, 10, 100, 100);</textarea>
var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); var textarea = document.getElementById("code"); var reset = document.getElementById("reset"); var edit = document.getElementById("edit"); var code = textarea.value; function drawCanvas() { ctx.clearRect(0, 0, canvas.width, canvas.height); eval(textarea.value); } reset.addEventListener("click", function() { textarea.value = code; drawCanvas(); }); edit.addEventListener("click", function() { textarea.focus(); }) textarea.addEventListener("input", drawCanvas); window.addEventListener("load", drawCanvas);
规范描述
Specification | Status | Comment |
---|---|---|
WHATWG HTML Living Standard CanvasRenderingContext2D.shadowOffsetX |
Living Standard |
浏览器兼容性
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |