检测不到HTML5 的最佳方式(Best way to detect that HTML5 is not supported)

检测不到HTML5 的最佳方式(Best way to detect that HTML5 is not supported)

处理浏览器不支持HTML5 <canvas>标记的情况的标准方法是嵌入一些备用内容，如：

<canvas>Your browser doesn't support "canvas".</canvas>

但是页面的其余部分保持不变，这可能是不恰当或误导的。 我想要一些检测画布不支持的方式，以便相应地显示我的页面的其余部分。 你会推荐什么

The standard way to deal with situations where the browser does not support the HTML5 <canvas> tag is to embed some fallback content like:

<canvas>Your browser doesn't support "canvas".</canvas>

But the rest of the page remains the same, which may be inappropriate or misleading. I'd like some way of detecting canvas non-support so that I can present the rest of my page accordingly. What would you recommend?

最满意答案

这是Modernizr中使用的技术，基本上每个其他绘画工作的图书馆都是：

function isCanvasSupported(){ var elem = document.createElement('canvas'); return !!(elem.getContext && elem.getContext('2d')); }

由于您的问题是在不支持的情况下进行检测，因此我建议使用它：

if (!isCanvasSupported()){ ...

This is the technique used in Modernizr and basically every other library that does canvas work:

function isCanvasSupported(){ var elem = document.createElement('canvas'); return !!(elem.getContext && elem.getContext('2d')); }

Since your question was for detection when it's not supported, I recommend using it like so:

if (!isCanvasSupported()){ ...