求教大神itk问题，初学itk

#include "itkTransformToDeformationFieldSource.h"
#include "itkRegularStepGradientDescentOptimizer.h"
typedef itk::TransformToDeformationFieldSource Transform2DeformationFieldGeneratorType;提示不允许使用限定名
怎么解决？
typedef itk::RegularStepGradientDescentOptimizer RegularStepGradientDescentOptimizerType;提示namespace"itk"没有成员RegularStepGradientDescentOptimizer，怎么解决？求大神指教