The Default style is a basic all-round style.
The Default style is a simple and light-weight style that offers the maximum performance for Qt Quick Controls 2. It is built with a minimal amount of Qt Quick primitives, and keeps animations and transitions to the minimum.
The style is selected by default when running Qt Quick Controls 2 applications. It is built into the module's resources, so by default it is shipped with any application that depends on the Qt Quick Controls 2 module
注意： The Default style is used as a fallback for other styles. If a style does not implement a certain control, the Default style implementation of that control is selected.
