这个图标在VS2019中是什么意思?

What does this icon mean in VS2019?

VS2019 16.10.0 .netfx Winform 项目。

此图标显示继承 chain/margin 并在 Visual Studio 的 16.10 版中添加。来自 16.10 release notes for Visual Studio:

There is now a visual representation for navigating and inspecting the inheritance chain. This option is off by default so you will need to turn it on in Tools > Options > Text Editor > C# > Advanced and select Show inheritance margin. Enabling inheritance margin will add new icons to the margins representing your code’s implementations and overrides. Clicking on the inheritance margin icon will display inheritance options that you can select to navigate to.

果然,如果您导航到工具菜单中的选项,它位于底部:

我会检查您的设置 - 默认情况下它应该是关闭的,这意味着 不知何故 它已为您打开。如果单击它,该图标应显示继承链。如果不是,也许关闭该选项然后重新打开,或者重新启动 Visual Studio(这显然是实验性的,因此可能会被窃听)。