[Unity插件]Lua行为树(四)：条件节点和行为节点

条件节点和行为节点，这两种节点本身的设计比较简单，项目中编写行为树节点一般就是扩展这两种节点，而Decorator和Composite节点只需要使用内置的就足够了。

它们的继承关系如下：

Conditional->Task

Action->Task

代码如下：

BTAction.lua

 1 BTAction = BTTask:New();
 2
 3 local this = BTAction;
 4
 5 function this:New()
 6     local o = {};
 7     setmetatable(o, self);
 8     self.__index = self;
 9     return o;
10 end

BTConditional.lua

 1 BTConditional = BTTask:New();
 2
 3 local this = BTConditional;
 4
 5 function this:New()
 6     local o = {};
 7     setmetatable(o, self);
 8     self.__index = self;
 9     return o;
10 end

BTLog.lua

 1 --[[
 2 参考BehaviorDesigner-Action-Log
 3 --]]
 4 BTLog = BTAction:New();
 5
 6 local this = BTLog;
 7
 8 function this:New(text)
 9     local o = {};
10     setmetatable(o, self);
11     self.__index = self;
12     o.text = text;
13     return o;
14 end
15
16 function this:OnUpdate()
17     print(self.text);
18     return BTTaskStatus.Success;
19 end

BTIsNullOrEmpty.lua

 1 --[[
 2 参考BehaviorDesigner-Conditional-IsNullOrEmpty
 3 --]]
 4 BTIsNullOrEmpty = BTConditional:New();
 5
 6 local this = BTIsNullOrEmpty;
 7
 8 function this:New(text)
 9     local o = {};
10     setmetatable(o, self);
11     self.__index = self;
12     o.text = text;
13     return o;
14 end
15
16 function this:OnUpdate()
17     if (not self.text or self.text == "") then
18         return BTTaskStatus.Success;
19     else
20         return BTTaskStatus.Failure;
21     end
22 end

TestBehaviorTree.lua

 1 TestBehaviorTree = BTBehaviorTree:New();
 2
 3 local this = TestBehaviorTree;
 4
 5 function this:New()
 6     local o = {};
 7     setmetatable(o, self);
 8     self.__index = self;
 9     this:Init();
10     return o;
11 end
12
13 function this:Init()
14     local sequence = BTSequence:New();
15     local isNullOrEmpty = BTIsNullOrEmpty:New("");
16     local log = BTLog:New("This is a empty string");
17     sequence:AddChild(isNullOrEmpty);
18     sequence:AddChild(log);
19     this:PushTask(sequence);
20 end

输出如下：

原文地址：https://www.cnblogs.com/lyh916/p/9575672.html