CanvasRenderingContext2D
.shadowColor
是 Canvas 2D API 描述阴影颜色的属性。
语法
ctx.shadowColor = color;
示例
使用 shadowColor
属性
这是一段简单的代码片段,使用 shadowColor
属性设置阴影的颜色。 注意:shadowColor属性设置成不透明的,并且 shadowBlur
、 shadowOffsetX
或者 shadowOffsetY
属性不为0,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.shadowOffsetY = 10; ctx.shadowOffsetX = 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.shadowOffsetY = 10; ctx.shadowOffsetX = 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.shadowColor |
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) |
WebKit/Blink-specific 注解
- 在基于 WebKit- 和 Blink- 的浏览器中,除了此属性外,还实现了一个不标准的并且不赞成使用的方法
ctx.setShadow()
。setShadow(width, height, blur, color, alpha); setShadow(width, height, blur, graylevel, alpha); setShadow(width, height, blur, r, g, b, a); setShadow(width, height, blur, c, m, y, k, a);
参见
- 接口定义,
CanvasRenderingContext2D
.