含義：

A handle to the location of a widget in the widget tree.

BuildContext是Widget在Widget樹中位置的句柄。

原因：

BuildContext?objects are actually?Element?objects. The?BuildContext?interface is used to discourage direct manipulation of?Element?objects.

BuildContext對象其實(shí)是一個element，BuildContext接口被用來阻止直接操作element對象；

特點(diǎn)：

Each widget has its own?BuildContext, which becomes the parent of the widget returned by the?StatelessWidget.build?or?State.build?function. (And similarly, the parent of any children for?RenderObjectWidgets.)

每個widget都有一個BuildContext，BuildContext會成為StatelessWidget.build?or?State.build?function返回widget的父親。

應(yīng)用

flow布局

在flow布局中BuildContext代表flow控件的位置，可以用來繪制子控件；