A graphics context created by CCoeEnv during its construction. It exists for the lifetime of the CCoeEnv object, and is typically used as the standard graphics context for drawing controls.

• 一个由CCoeEnv在其构造时创建的绘图上下文环境。它在整个CCoeEnv对象的生命周期存在,它典型的应用是为绘图控件作为一个标准的绘图上下文环境。