alongLineAngleMoveDistancePt alongLineNormalDir alongLineNormalMoveDistancePt Angle Distance Distance FromPolar GetAngle IsEqual IsLess IsNull Length moveAlongLine Negate Normalize operator* operator* operator*= operator+ operator+ operator+= operator- operator- operator-= operator/ operator/= operator= operator== Perpendicular perpendicularPointOnLine ProjectToLine Rotate Scale Set Sqr Vector2d Vector2d Vector2d Vector2d x y

GetAngle() double GetAngle ( const Vector2d &  v ) const 计算两个向量之间的夹角 计算当前向量与另一个向量之间的夹角。 参数 [in] v 另一个向量 返回 两个向量之间的夹角