如何检测浏览器的协议处理程序？

我创建一个自定义URL协议处理程序。

I have created a custom URL protocol handler.

的http：//

至mailto：//

自定义的：//

custom://

我已经注册了一个WinForms应用程序作出相应的反应。这一切的伟大工程。

I have registered a WinForms application to respond accordingly. This all works great.

不过，我想能够正常处理的情况下，用户没有安装自定义URL协议处理程序，但。

But I would like to be able to gracefully handle the case where the user doesn't have the custom URL protocol handler installed, yet.

在为了能够做到这一点，我需要能够检测浏览器的注册协议处理程序，我会从JavaScript承担。但我一直无法找到一个方法来轮询的信息。我希望能找到解决这个问题。

In order to be able to do this I need to be able to detect the browser's registered protocol handlers, I would assume from JavaScript. But I have been unable to find a way to poll for the information. I am hoping to find a solution to this problem.

谢谢你也许可以分享任何想法。

Thanks for any ideas you might be able to share.