在unity5.0中做賽車遊戲這個句子怎麽替換rigidbody.centerOfMass.x = COMX;？

Rigidbody RD = gameobject.rigidbody;錯誤

Rigidbody RD = gameobject.GetComponent<Rigidbody>();正確

gameobject.rigidbody.centerOfMass.x = COMX; 錯誤

gameobject.GetComponent<Rigidbody>().centerOfMass.x = COMX; 正確