探讨行为树的任务

任务

在最高级别，行为树是任务的集合。任务类具有以下API：

// OnAwake is called once when the behavior tree is enabled. Think of it as a constructor.
void OnAwake();
 
// OnStart is called immediately before execution. It is used to setup any variables that need to be reset from the previous run.
void OnStart();
 
// OnUpdate runs the actual task.
TaskStatus OnUpdate();
 
// OnFixedUpdate executes during the FixedUpdate loop. The TaskStatus must be returned within OnUpdate.
void OnFixedUpdate();
 
// OnEnd is called after execution on a success or failure. 
void OnEnd();
 
// OnPause is called when the behavior is paused or resumed.
void OnPause(bool paused);
 
// Ret