在设计界面时，通常都编写一个配置方法（如SetZoomPan），在窗体载入时调用进行默认的设置（参数为空），如果需要修改则单独调用，并传递一个指定的配置对象。希望用指定的配置对象覆盖默认的设置。

   SetZoomPan(new ZoomPanOptions3D
            {
                RotationSensitivity=12
            });

 具体方法的实现

public void SetZoomPan(ZoomPanOptions3D options=null)
        {
           
            
            _lightningChart.View3D.ZoomPanOptions.AutoFit = options?.AutoFit ?? true;

            _lightningChart.View3D.ZoomPanOptions.LeftMouseButtonAction = options?.LeftMouseButtonAction ?? MouseButtonAction3D.Rotate;
            _lightningChart.View3D.ZoomPanOptions.RotationSensitivity = options?.RotationSensitivity ?? 1;

            // _lightningChart.View3D.ZoomPanOptions.MiddleMouseButtonAction = MouseButtonAction3D.ZoomX;
            _lightningChart.View3D.ZoomPanOptions.MouseWheelZoomEnabled = true;
            _lightningChart.View3D.ZoomPanOptions.MouseWheelZoomFactor = 1.2;

            _lightningChart.View3D.ZoomPanOptions.RightMouseButtonAction = MouseButtonAction3D.Pan;
            _lightningChart.View3D.ZoomPanOptions.PanSensitivity = 20;
        }

 要点：

（1）定义默认参数options=null，用户在调用的时候可以不用填写参数

（2）_lightningChart.View3D.ZoomPanOptions.AutoFit = options?.AutoFit ?? true;  等同于 

if(options!=null){

     if(options.AutoFit==null){

     _lightningChart.View3D.ZoomPanOptions.AutoFit =true；
   
   }else{

      _lightningChart.View3D.ZoomPanOptions.AutoFit =options.AutoFit；

    }

}