Component
Component是附加在GameObject上的功能模块，每个组件都提供了某种行为或属性，组成了游戏对象的功能 class Component继承自Object，在UnityEngine.CoreModule中实现
class Component
是所有可依附在GameObject上的类的基类
不可以直接创建Component
API
Properties
| Property | Description |
|---|---|
| gameObject | component附加的GameObject |
| tag | gameObject的tag |
| transform | gameObject的Transform |
Public Methods
| 方法 | 描述 |
|---|---|
BroadcastMessage | 调用当前 GameObject 或其所有子对象的指定方法。 |
CompareTag | 比较 GameObject 的标签（tag）与给定标签。 |
GetComponent | 获取当前 GameObject 上的指定类型的组件。 |
GetComponentInChildren | 获取当前 GameObject 或其子对象上的指定类型的组件。 |
GetComponentIndex | 获取组件在其父对象中的索引。 |
GetComponentInParent | 获取当前 GameObject 或其父对象上的指定类型的组件。 |
GetComponents | 获取当前 GameObject 上的所有指定类型的组件。 |
GetComponentsInChildren | 获取当前 GameObject 和其子对象上的所有指定类型的组件。 |
GetComponentsInParent | 获取当前 GameObject 和其父对象上的所有指定类型的组件。 |
SendMessage | 在当前 GameObject 上调用指定的方法，所有附加的 MonoBehaviour 都会收到此消息。 |
SendMessageUpwards | 调用当前 GameObject 及其所有祖先对象上的指定方法。 |
TryGetComponent | 尝试获取指定类型的组件，如果存在则返回该组件，否则返回 null。 |
组件的特性
| 特性 | 描述 |
|---|---|
| 附加性 | 可以给 GameObject 添加多个组件。 |
| 组合式设计 | Unity 的架构是组合优于继承，一个 GameObject 的行为是由多个组件组合而成的。 |
| 可视化编辑 | 在 Unity Inspector 面板中可以直接添加、删除或修改组件。 |
| 脚本组件 | 你写的 C# 脚本，本质上也是组件，继承自 MonoBehaviour。 |
在代码中使用组件
//获取组件
Rigidbody rb = GetComponent<Rigidbody>();
//添加组件
gameObject.AddComponent<AudioSource>();
在Unity中，组件之所以能起作用，是因为Unity引擎在运行时会自动调度和执行组件的逻辑，这个背后是Unity引擎的核心“组件驱动”架构
简单理解：Unity的工作循环 + 组件系统
1.GameObject只是容器 2.组件发挥功能 3.Unity引擎每一帧都会遍历所有激活的GameObject，调度它们的组件做该做的事
Unity组件
| Category | Component Name |
|---|---|
| Audio | Chorus Filter |
| Distortion Filter | |
| Echo Filter | |
| High Pass Filter | |
| Listener | |
| Low Pass Filter | |
| Reverv Filter | |
| Reverv Zone | |
| Source | |
| Effects | Halo |
| Lens Flare | |
| Line Renderer | |
| Particle System | |
| Projector | |
| Trail Renderer | |
| Visual Effect | |
| Event | Event System |
| Event Trigger | |
| Graphic Raycaster | |
| Physics 2D Raycaster | |
| Physics Raycaster | |
| Standalone Input Module | |
| Touch Input Module | |
| Layout | Aspect Ratio Fitter |
| Canvas | |
| Canvas Group | |
| Cancas Scaler | |
| Content Size Fitter | |
| Grid Layout Group | |
| Horizontal Layout Group | |
| Layout Element | |
| Rect Transform | |
| Vertical Layout Group | |
| Mesh | Mesh Filter |
| Mesh Renderer | |
| Skinned Mesh Renderer | |
| TextMeshPro - Text | |
| Text Mesh (Legacy) | |
| Miscellaneous | Aim Constraint |
| Animation | |
| Animator | |
| Billboard Renderer | |
| Grid | |
| Look At Constraint | |
| Parent Constraint | |
| Particle System Force Field | |
| Position Constraint | |
| Rotation Constraint | |
| Scale Constraint | |
| Sprite Mask | |
| Sprite Shape Renderer | |
| Terrain | |
| Wind Zone | |
| Navigation | Nav Mesh Agent |
| Nav Mesh Obstacle | |
| Off Mesh Link | |
| Physics 2D | Area Effector 2D |
| Box Collider 2D | |
| Buoyancy Effector 2D | |
| Capsule Collider 2D | |
| Circle Collider 2D | |
| Composite Collider 2D | |
| Constant Force 2D | |
| Custom Collider 2D | |
| Distance Joint 2D | |
| Edge Collider 2D | |
| Fixed Joint 2D | |
| Friction Joint 2D | |
| Hinge Joint 2D | |
| Platform Effector 2D | |
| Point Effector 2D | |
| Polygon Collider 2D | |
| Relative Joint 2D | |
| Rigidbody 2D | |
| Slider Joint 2D | |
| Spring Joint 2D | |
| Surface Effector 2D | |
| Target Joint 2D | |
| Wheel Joint 2D | |
| Physics | Articulation Body |
| Box Collider | |
| Capsule Collider | |
| Character Controller | |
| Character Joint | |
| Cloth | |
| Configurable Joint | |
| Constant Force | |
| Fixed Joint | |
| Hinge Joint | |
| Mesh Collider | |
| Rigidbody | |
| Sphere Collider | |
| Spring Joint | |
| Terrain Collider | |
| Wheel Collider | |
| Playables | Playable Director |
| Rendering | Camera |
| Canvas Renderer | |
| Flare Layer | |
| LOD Group | |
| Light | |
| Light Probe Group | |
| Light Probe Proxy Volume | |
| Occlusion Area | |
| Occlusion Portal | |
| Reflection Probe | |
| Skybox | |
| Sorting Group | |
| Sprite Renderer | |
| Streaming Controller | |
| Scripts | 自定义脚本 |
| Tilemap | Tilemap |
| Tilemap Collider 2D | |
| Tilemap Renderer | |
| UI Toolkit | Panel Event Handler |
| Panel Raycaster | |
| UI Document | |
| UI | Button |
| Dropdown - TMP | |
| Effects - Outline | |
| Effects - Position As UV1 | |
| Effects - Shadow | |
| Image | |
| Mask | |
| Raw Image | |
| Rect Mask 2D | |
| Scroll Rect | |
| Scrollbar | |
| Selectable | |
| Slider | |
| TMP - Input Field | |
| TMP - Text | |
| Toggle | |
| Toggle Group | |
| Dropdown (Legacy) | |
| Input Field (Legacy) | |
| Text (Legacy) | |
| Video | Video Player |
| Visual Scripting | Animator Message Listener (Listener) |
| Script Machine | |
| State Machine | |
| Variables |