Visual Mac的Studio 2017实际上与Windows的Visual Studio不同。如您所知，它最初基于Xamarin Studio，而Xamarin Studio则是MonoDevelop的扩展形式。

简单地说，您将在 Visual Studio中找到的扩展名市场 与Visual Studio 2017 for Mac不兼容。

VS2017 Mac版确实有自己的市场，可从扩展管理器中访问。您可以通过以下方式从IDE内部访问它：

Visual Studio菜单>扩展

在扩展管理器中，您可以会找到可用扩展的非常小的列表。但是，一个巧妙的技巧是查看存储库的源代码，该存储库只是旧的MonoDevelop目录 http：//addins.monodevelop .com /

将其包装起来，您可以添加第三方扩展URL或通过文件安装社区软件包，但基本上说，拥有相同经验和广泛产品（如常规市场）所能提供的功能不多。

Can someone help me because l have no idea how to install extensions from the Market Place on visual studio 2017

Visual Studio 2017 for Mac is actually a different beast from Visual Studio for Windows. As you may know, it is originally based on Xamarin Studio which on its turn is an extended form of MonoDevelop.

Simply put, the extensions you'll find in the Visual Studio Marketplace are not compatible with Visual Studio 2017 for Mac.

VS2017 for Mac does have its own marketplace, which is accessible from the Extension Manager. You can access it from inside the IDE through:
Visual Studio menu > Extensions

In the Extension Manager, you'll find a pretty small list of available extensions. But a neat trick is to look at the source of the repositories, which is simply the old MonoDevelop catalog http://addins.monodevelop.com/

Wrapping it up, you can add third party extension url's or install community packages through a file, but basically put there is not a lot more that you can get with the same experience and broad offering like the 'regular' Marketplace.