GameFramework.AiLogicUtility.GetNearstAttackerHelper C# (CSharp) Method

        public static EntityInfo GetNearstAttackerHelper(EntityInfo srcObj, CharacterRelation relation, AiData_General aidata)
        {
            EntityInfo ret = null;
            float minDistSqr = 999999;
            Vector2 dir = srcObj.GetMovementStateInfo().GetFaceDir2D();
            Vector2 pos = srcObj.GetMovementStateInfo().GetPosition2D();
            if (relation == CharacterRelation.RELATION_ENEMY) {
                foreach (var pair in srcObj.AttackerInfos) {
                    EntityInfo target = srcObj.SceneContext.GetEntityById(pair.Key);
                    if (null != target) {
                        float distSqr = Geometry.DistanceSquare(pos, target.GetMovementStateInfo().GetPosition2D());
                        if (distSqr <= (srcObj.ViewRange + target.GetRadius()) * (srcObj.ViewRange + target.GetRadius())) {
                            if (distSqr <= minDistSqr) {
                                ret = target;
                                minDistSqr = distSqr;
                            }
                        }
                    }
                }
            }
            return ret;
        }

        private void CombatHandler(EntityInfo npc, long deltaTime)
        {
            AiStateInfo   aiInfo = npc.GetAiStateInfo();
            AiData_Leader aiData = GetAiData(npc);

            if (npc.GetSkillStateInfo().IsSkillActivated())
            {
                return;
            }
            ///
            SkillStateInfo currSkInfo = npc.GetSkillStateInfo();
            ///找到可以使用的技能
            SkillInfo skInfo = AiLogicUtility.NpcFindCanUseSkill(npc, this.GetAiData(npc), aiData.IsAutoOperate);

            NotifyAiSelectSkill(npc, skInfo);
            if (skInfo == null)
            {
                //没有可以使用的技能就切换到Idle状态
                ChangeToState(npc, (int)AiStateId.Idle);
                return;
            }

            CharacterRelation relation =
                (skInfo.TargetType == SkillTargetType.Friend ||
                 skInfo.TargetType == SkillTargetType.RandFriend) ?
                CharacterRelation.RELATION_FRIEND :
                CharacterRelation.RELATION_ENEMY;
            EntityInfo attackTarget = AiLogicUtility.GetNearstAttackerHelper(npc, relation, aiData);

            if (null != attackTarget)
            {
                NotifyAiTarget(npc, attackTarget);
                if (Geometry.DistanceSquare(npc.GetMovementStateInfo().GetPosition3D(), attackTarget.GetMovementStateInfo().GetPosition3D()) < skInfo.Distance * skInfo.Distance)
                {
                    aiInfo.Target = attackTarget.GetId();
                    NotifyAiStopPursue(npc);
                    NotifyAiSkill(npc, skInfo.SkillId);
                    return;
                }
            }
            attackTarget = AiLogicUtility.GetNearstTargetHelper(npc, skInfo.Distance, relation);
            if (attackTarget != null && null != skInfo)   //攻击范围内找到可攻击目标
            {
                NotifyAiTarget(npc, attackTarget);
                aiInfo.Target = attackTarget.GetId();
                NotifyAiStopPursue(npc);
                NotifyAiSkill(npc, skInfo.SkillId); //攻击目标
                return;
            }
            if (aiData.IsAutoOperate)
            {
                attackTarget = AiLogicUtility.GetNearstTargetHelper(npc, npc.ViewRange, relation);
                if (attackTarget != null && null != skInfo)   //视野内找到可攻击目标
                {
                    NotifyAiPursue(npc, attackTarget.GetMovementStateInfo().GetPosition3D());
                    return;
                }
            }

            ///退出战斗模式清理一下手动技能
            currSkInfo.SetCurSkillInfo(0);
            aiData.ManualSkillId = 0;
            NotifyAiStopPursue(npc);
            ChangeToState(npc, (int)AiStateId.Idle);
        }