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您的第一个网络组件

按照本教程开始在 Open 3D Engine （O3DE）中创建多人游戏组件。在本教程结束时，您将了解如何创建具有 network 属性和 remote 过程调用的新网络组件。

首先，构建并运行 O3DE MultiplayerSample 项目。有关如何构建和运行此项目的说明，请参阅 MultiplayerSample Project README 。

网络组件

添加新组件

我们首先创建一个网络组件 - MyFirstNetworkComponent。它只会做一件事，那就是复制一个单调计数器。

由于我们已经为自动代码生成（codegen）设置了 MultiplayerSample，因此我们可以从复制一个现有的 codegen xml 文件开始。

复制 <o3de-multiplayersample>\Gem\Code\Source\AutoGen\SimplePlayerCameraComponent.AutoComponent.xml 到 <o3de-multiplayersample>\Gem\Code\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.xml

修改 <o3de-multiplayersample>\Gem\Code\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.xml 以包含以下内容：

<Component Name="MyFirstNetworkComponent"
        Namespace="MultiplayerSample"
        OverrideComponent="true"
        OverrideController="false"
        OverrideInclude="Source/Components/MyFirstNetworkComponent.h"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
</Component>

到 <o3de-multiplayersample>\Gem\Code\multiplayersample_files.cmake 并添加新的 XML 文件：
```
set(FILES
...
    Source/AutoGen/MyFirstNetworkComponent.AutoComponent.xml
```

为您的 O3DE 项目重新运行 CMake configure，或构建MultiplayerSample.Static。失败是意料之中的，因为我们没有在代码生成的文件之上编写代码。

3>------ Build started: Project: MultiplayerSample.Static, Configuration: profile x64 ------
3>Generating Azcg/Generated/Source/AutoGen/NetworkAnimationComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/NetworkCharacterComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/NetworkHitVolumesComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/NetworkPlayerSpawnerComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/NetworkRigidBodyComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/NetworkWeaponsComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/MyFirstNetworkComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/SimplePlayerCameraComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/WasdPlayerMovementComponent.AutoComponent.h, Azcg/Generated/Source/AutoGen/NetworkAnimationComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/NetworkCharacterComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/NetworkHitVolumesComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/NetworkPlayerSpawnerComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/NetworkRigidBodyComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/NetworkWeaponsComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/MyFirstNetworkComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/SimplePlayerCameraComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/WasdPlayerMovementComponent.AutoComponent.cpp, Azcg/Generated/Source/AutoGen/AutoComponentTypes.h, Azcg/Generated/Source/AutoGen/AutoComponentTypes.cpp
3>Running AutoGen for MultiplayerSample.Static
3>Generating D:\git\o3de\build\-86ba765d\Gem\Code\Azcg\Generated\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.h with template D:/git/o3de/Gems/Multiplayer/Code/Source/AutoGen/AutoComponent_Header.jinja and inputs D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.xml
3>Generating D:\git\o3de\build\-86ba765d\Gem\Code\Azcg\Generated\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.cpp with template D:/git/o3de/Gems/Multiplayer/Code/Source/AutoGen/AutoComponent_Source.jinja and inputs D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.xml
3>Generating D:\git\o3de\build\-86ba765d\Gem\Code\Azcg\Generated\Source\AutoGen\AutoComponentTypes.cpp with template D:/git/o3de/Gems/Multiplayer/Code/Source/AutoGen/AutoComponentTypes_Source.jinja and inputs D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\NetworkAnimationComponent.AutoComponent.xml, D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\NetworkCharacterComponent.AutoComponent.xml, D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\NetworkHitVolumesComponent.AutoComponent.xml, D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\NetworkPlayerSpawnerComponent.AutoComponent.xml, D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\NetworkRigidBodyComponent.AutoComponent.xml, D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\NetworkWeaponsComponent.AutoComponent.xml, D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.xml, D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\SimplePlayerCameraComponent.AutoComponent.xml, D:\git\o3de-multiplayersample\Gem\Code\Source\AutoGen\WasdPlayerMovementComponent.AutoComponent.xml
3>Total Time 0:00:00.01
3>MyFirstNetworkComponent.AutoComponent.cpp
3>AutoComponentTypes.cpp
3>D:\git\o3de\build\-86ba765d\Gem\Code\Azcg\Generated\Source\AutoGen\AutoComponentTypes.cpp(14,10): fatal error C1083: Cannot open include file: 'Source/Components/MyFirstNetworkComponent.h': No such file or directory
3>#include <Source/Components/MyFirstNetworkComponent.h>
3>         ^
3>D:\git\o3de\build\-86ba765d\Gem\Code\Azcg\Generated\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.cpp(20,10): fatal error C1083: Cannot open include file: 'Source/Components/MyFirstNetworkComponent.h': No such file or directory
3>#include <Source/Components/MyFirstNetworkComponent.h>
3>         ^
3>Done building project "MultiplayerSample.Static.vcxproj" -- FAILED.

请注意我们到目前为止得到的结果：

3>Generating D:\git\o3de\build\-86ba765d\Gem\Code\Azcg\Generated\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.h ...
3>Generating D:\git\o3de\build\-86ba765d\Gem\Code\Azcg\Generated\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.cpp ...

打开头文件 MyFirstNetworkComponent.AutoComponent.h 并查找以下大型注释块：

/*
/// You may use the classes below as a basis for your new derived classes. Derived classes must be marked in MyFirstNetworkComponent.AutoComponent.xml
/// Place in your .h
#pragma once

#include <Source/AutoGen/MyFirstNetworkComponent.AutoComponent.h>

namespace MultiplayerSample
{
    class MyFirstNetworkComponent
        : public MyFirstNetworkComponentBase
    {
    public:
        AZ_MULTIPLAYER_COMPONENT(MultiplayerSample::MyFirstNetworkComponent, s_myFirstNetworkComponentConcreteUuid, MultiplayerSample::MyFirstNetworkComponentBase);

        static void Reflect(AZ::ReflectContext* context);

        void OnInit() override;
        void OnActivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;
        void OnDeactivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;




    protected:

    };

}
/// Place in your .cpp
#include <Source/Components/MyFirstNetworkComponent.h>

namespace MultiplayerSample
{
    void MyFirstNetworkComponent::Reflect(AZ::ReflectContext* context)
    {
        AZ::SerializeContext* serializeContext = azrtti_cast<AZ::SerializeContext*>(context);
        if (serializeContext)
        {
            serializeContext->Class<MyFirstNetworkComponent, MyFirstNetworkComponentBase>()
                ->Version(1);
        }
        MyFirstNetworkComponentBase::Reflect(context);
    }

    void MyFirstNetworkComponent::OnInit()
    {
    }

    void MyFirstNetworkComponent::OnActivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
    {
    }

    void MyFirstNetworkComponent::OnDeactivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
    {
    }

}
*/

前一个块中的代码是我们的起始基数。将该代码复制粘贴到<o3de-multiplayersample>\Gem\Code\Source\Components\MyFirstNetworkComponent.h 和 <o3de-multiplayersample>\Gem\Code\Source\Components\MyFirstNetworkComponent.cpp.

将这些文件添加到 <o3de-multiplayersample>\Gem\Code\multiplayersample_files.cmake:

set(FILES
...
    Source/Components/MyFirstNetworkComponent.cpp
    Source/Components/MyFirstNetworkComponent.h

现在，MultiplayerSample 项目应该可以编译，没有任何问题。打开 O3DE 编辑器 以在 Editor 中查看新组件。
Additionally, you can find the generated files and your XML file in Visual Studio:
此时，您有一个名为MyFirstNetworkComponent的多人组件。

添加网络属性

让我们添加一个网络属性，该属性会将运行时间从服务器复制到客户端。

首先修改MyFirstNetworkComponent.AutoComponent.xml。以下是具有 network 属性的 codegen xml 文件：

<?xml version="1.0"?>
<Component Name="MyFirstNetworkComponent"
        Namespace="MultiplayerSample"
        OverrideComponent="true"
        OverrideController="false"
        OverrideInclude="Source/Components/MyFirstNetworkComponent.h"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<NetworkProperty Type="double"
                Name="UpTime"
                Init="0.0"
                ReplicateFrom="Authority"
                ReplicateTo="Client"
                IsRewindable="true"
                IsPredictable="true"
                IsPublic="true"
                Container="Object"
                ExposeToEditor="false"
                ExposeToScript="false"
                GenerateEventBindings="false"
                Description="Time since the start of the application" />
</Component>

重点介绍NetworkProperty的基本详细信息。这些是：

<NetworkProperty Type="double"
                Name="UpTime"
                Init="0.0"
                ReplicateFrom="Authority"
                ReplicateTo="Client"

用 C++ 表示，如下所示：

double m_UpTime = 0.0; // replicate from Authority to Client

注意:
目前，我们可以将 ‘Authority’ 视为多人游戏服务器。对Client的Authority是最常见的复制方向。

通过这些更改，MyFirstNetworkComponent可以通过客户端上的 GetUpTime（）方法访问 UpTime。在授权服务器上，我们可以通过访问组件的控制器 - MyFirstNetworkComponentController 来设置UpTime的值，使用以下代码：

    void MyFirstNetworkComponent::OnTick( [[maybe_unused]] float deltaTime, AZ::ScriptTimePoint time )
    {
        if ( HasController() )
        {
            auto* controller = static_cast<MyFirstNetworkComponentController*>( GetController() );
            controller->ModifyUpTime() = time.GetSeconds();
            AZ_Printf( "MyFirstNetworkComponent", "server = %f", GetUpTime() );
        }
        else
        {
            AZ_Printf( "MyFirstNetworkComponent", "client = %f", GetUpTime() );
        }
    }

注意:
控制器仅存在于授权服务器上，因此这有效地将执行拆分为仅服务器和仅客户端逻辑。

到目前为止，该组件的完整代码如下。头文件为<o3de-multiplayersample>\Gem\Code\Source\Components\MyFirstNetworkComponent.h:

#pragma once

#include <Source/AutoGen/MyFirstNetworkComponent.AutoComponent.h>
#include <AzCore/Component/TickBus.h>

namespace MultiplayerSample
{
    class MyFirstNetworkComponent
        : public MyFirstNetworkComponentBase
        , public AZ::TickBus::Handler
    {
    public:
        AZ_MULTIPLAYER_COMPONENT(MultiplayerSample::MyFirstNetworkComponent, s_myFirstNetworkComponentConcreteUuid, MultiplayerSample::MyFirstNetworkComponentBase);

        static void Reflect(AZ::ReflectContext* context);

        void OnInit() override;
        void OnActivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;
        void OnDeactivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;

        void OnTick(float deltaTime, AZ::ScriptTimePoint time) override;
    };
}

源文件， <o3de-multiplayersample>\Gem\Code\Source\Components\MyFirstNetworkComponent.cpp:

#include <Source/Components/MyFirstNetworkComponent.h>

#include <AzCore/Serialization/SerializeContext.h>

namespace MultiplayerSample
{
    void MyFirstNetworkComponent::Reflect( AZ::ReflectContext* context )
    {
        AZ::SerializeContext* serializeContext = azrtti_cast<AZ::SerializeContext*>( context );
        if ( serializeContext )
        {
            serializeContext->Class<MyFirstNetworkComponent, MyFirstNetworkComponentBase>()
                ->Version( 1 );
        }
        MyFirstNetworkComponentBase::Reflect( context );
    }

    void MyFirstNetworkComponent::OnInit()
    {
    }

    void MyFirstNetworkComponent::OnActivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
    {
        AZ::TickBus::Handler::BusConnect();
    }

    void MyFirstNetworkComponent::OnDeactivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
    {
        AZ::TickBus::Handler::BusDisconnect();
    }

    void MyFirstNetworkComponent::OnTick( [[maybe_unused]] float deltaTime, AZ::ScriptTimePoint time )
    {
        if ( HasController() )
        {
            auto* controller = static_cast<MyFirstNetworkComponentController*>( GetController() );
            controller->ModifyUpTime() = time.GetSeconds();
            AZ_Printf( "MyFirstNetworkComponent", "server = %f", GetUpTime() );
        }
        else
        {
            AZ_Printf( "MyFirstNetworkComponent", "client = %f", GetUpTime() );
        }
    }
}

现在，您有一个具有 network 属性的 multiplayer 组件。

监听客户端上的网络属性更改

但是，让我们对此进行改进。客户端不需要 tick，它可以监听更改。为此，请启用 GenerateEventBindings。这就是我们目前所拥有的。

  <NetworkProperty Type="double"
                   Name="UpTime"
...
                   GenerateEventBindings="false"
...
                    />

修改 GenerateEventBindings 为 true:

  <NetworkProperty Type="double"
                   Name="UpTime"
...
                   GenerateEventBindings="true"
...
                    />

项目构建将生成一个新方法：UpTimeAddEvent。让我们在代码中使用它。

要监听组件中客户端的更改，请执行以下操作：

创建事件处理程序。

// create an event handler
AZ::Event<double>::Handler m_uptimeChanged;

创建回调方法。
```
void OnUpTimeChanged( double uptime );
```

将其分配给事件处理程序。

// assign the callback to the event handler
MyFirstNetworkComponent::MyFirstNetworkComponent()
    : m_uptimeChanged( [this]( double uptime ) {OnUpTimeChanged( uptime ); } )
{
}

将事件处理程序连接到 UpTimeAddEvent。

// connect the event handler to the generated UpTimeAddEvent method
void MyFirstNetworkComponent::OnActivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
{
    UpTimeAddEvent( m_uptimeChanged );
}

现在，无需在客户端上打勾，而是从回调中打印我们的日志消息：

void MyFirstNetworkComponent::OnUpTimeChanged( double uptime )
{
    AZ_Printf( "MyFirstNetworkComponent", "client = %f", uptime );
}

进行这些更改后，MyFirstNetworkComponent.h应如下所示：

#pragma once

#include <Source/AutoGen/MyFirstNetworkComponent.AutoComponent.h>
#include <AzCore/Component/TickBus.h>

namespace MultiplayerSample
{
    class MyFirstNetworkComponent
        : public MyFirstNetworkComponentBase
        , public AZ::TickBus::Handler
    {
    public:
        AZ_MULTIPLAYER_COMPONENT( MultiplayerSample::MyFirstNetworkComponent, s_myFirstNetworkComponentConcreteUuid, MultiplayerSample::MyFirstNetworkComponentBase );

        static void Reflect( AZ::ReflectContext* context );

        MyFirstNetworkComponent();

        void OnInit() override;
        void OnActivate( Multiplayer::EntityIsMigrating entityIsMigrating ) override;
        void OnDeactivate( Multiplayer::EntityIsMigrating entityIsMigrating ) override;

        void OnTick( float deltaTime, AZ::ScriptTimePoint time ) override;

    private:
        AZ::Event<double>::Handler m_uptimeChanged;
        void OnUpTimeChanged( double uptime );
    };
}

并且 MyFirstNetworkComponent.cpp应如下所示：

#include <Source/Components/MyFirstNetworkComponent.h>

#include <AzCore/Serialization/SerializeContext.h>

namespace MultiplayerSample
{
    void MyFirstNetworkComponent::Reflect( AZ::ReflectContext* context )
    {
        AZ::SerializeContext* serializeContext = azrtti_cast<AZ::SerializeContext*>( context );
        if ( serializeContext )
        {
            serializeContext->Class<MyFirstNetworkComponent, MyFirstNetworkComponentBase>()
                ->Version( 1 );
        }
        MyFirstNetworkComponentBase::Reflect( context );
    }

    MyFirstNetworkComponent::MyFirstNetworkComponent()
        : m_uptimeChanged( [this]( double uptime ) {OnUpTimeChanged( uptime ); } )
    {
    }

    void MyFirstNetworkComponent::OnInit()
    {
    }

    void MyFirstNetworkComponent::OnActivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
    {
        UpTimeAddEvent( m_uptimeChanged );

        if ( HasController() )
        {
            AZ::TickBus::Handler::BusConnect();
        }
    }

    void MyFirstNetworkComponent::OnDeactivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
    {
        AZ::TickBus::Handler::BusDisconnect();
    }

    void MyFirstNetworkComponent::OnTick( [[maybe_unused]] float deltaTime, AZ::ScriptTimePoint time )
    {
        // only happens on Authority (server)
        auto* controller = static_cast<MyFirstNetworkComponentController*>( GetController() );
        controller->ModifyUpTime() = time.GetSeconds();
        AZ_Printf( "MyFirstNetworkComponent", "server = %f", GetUpTime() );
    }

    void MyFirstNetworkComponent::OnUpTimeChanged( double uptime )
    {
        AZ_Printf( "MyFirstNetworkComponent", "client = %f", uptime );
    }
}

网络组件控制器

让我们改进一下服务器代码和客户端代码之间的分离。目前，MyFirstNetworkComponent同时执行服务器和客户端任务。让我们把它分解开来。在 O3DE 多人游戏中，做到这一点的方法是使用“控制器”。控制器不存在 Client 角色中，但存在于 Authority 角色上。我们已经在前面的示例中看到了这一点：

auto* controller = static_cast<MyFirstNetworkComponentController*>( GetController() );

返回到 codegen XML，<o3de-multiplayersample>\Gem\Code\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.xml，其中控制器在属性OverrideController中提到：

<Component Name="MyFirstNetworkComponent"
        Namespace="MultiplayerSample"
        OverrideComponent="true"
        OverrideController="false"

将 OverrideController 更改为 true，以便我们可以在控制器中编写自定义逻辑。

<Component Name="MyFirstNetworkComponent"
        Namespace="MultiplayerSample"
        OverrideComponent="true"
        OverrideController="true"

构建项目。
尝试构建代码时，您将收到预期的编译错误。这是因为 codegen 希望我们覆盖控制器基类。

查看代码生成的头文件，\path\to\o3de\build\-86ba765d\Gem\Code\Azcg\Generated\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.h, 您会发现 Codegen 修改了大注释，现在包含控制器的代码示例：

/// You may use the classes below as a basis for your new derived classes. Derived classes must be marked in MyFirstNetworkComponent.AutoComponent.xml
/*
    class MyFirstNetworkComponentController
        : public MyFirstNetworkComponentControllerBase
    {
    public:
        MyFirstNetworkComponentController(MyFirstNetworkComponent& parent);

        void OnActivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;
        void OnDeactivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;
    };

    MyFirstNetworkComponentController::MyFirstNetworkComponentController(MyFirstNetworkComponent& parent)
        : MyFirstNetworkComponentControllerBase(parent)
    {
    }

    void MyFirstNetworkComponentController::OnActivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
    {
    }

    void MyFirstNetworkComponentController::OnDeactivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
    {
    }
*/

将此内容添加到我们现有的<o3de-multiplayersample>\Gem\Code\Source\Components\MyFirstNetworkComponent.h 和 <o3de-multiplayersample>\Gem\Code\Source\Components\MyFirstNetworkComponent.cpp.

将所有服务器逻辑移动到MyFirstNetworkComponentController，并保留 MyFirstNetworkComponent中的客户端逻辑，如以下更新的文件所示，<o3de-multiplayersample>\Gem\Code\Source\Components\MyFirstNetworkComponent.h:

#pragma once

#include <Source/AutoGen/MyFirstNetworkComponent.AutoComponent.h>
#include <AzCore/Component/TickBus.h>

namespace MultiplayerSample
{
    class MyFirstNetworkComponent
        : public MyFirstNetworkComponentBase
    {
    public:
        AZ_MULTIPLAYER_COMPONENT( MultiplayerSample::MyFirstNetworkComponent, s_myFirstNetworkComponentConcreteUuid, MultiplayerSample::MyFirstNetworkComponentBase );

        static void Reflect( AZ::ReflectContext* context );

        MyFirstNetworkComponent();

        void OnInit() override {}
        void OnActivate( Multiplayer::EntityIsMigrating entityIsMigrating ) override;
        void OnDeactivate( Multiplayer::EntityIsMigrating entityIsMigrating ) override;

    private:
        AZ::Event<double>::Handler m_uptimeChanged;
        void OnUpTimeChanged( double uptime );
    };

    class MyFirstNetworkComponentController
        : public MyFirstNetworkComponentControllerBase
        , public AZ::TickBus::Handler
    {
    public:
        MyFirstNetworkComponentController(MyFirstNetworkComponent& parent);

        void OnActivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;
        void OnDeactivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;

        void OnTick( float deltaTime, AZ::ScriptTimePoint time ) override;
    };
}

请注意头文件中的主要区别： AZ::TickBus::Handler 从 MyFirstNetworkComponent 移动到 MyFirstNetworkComponentController，在 <o3de-multiplayersample>\Gem\Code\Source\Components\MyFirstNetworkComponent.cpp中:

#include <Source/Components/MyFirstNetworkComponent.h>

#include <AzCore/Serialization/SerializeContext.h>

namespace MultiplayerSample
{
    void MyFirstNetworkComponent::Reflect( AZ::ReflectContext* context )
    {
        AZ::SerializeContext* serializeContext = azrtti_cast<AZ::SerializeContext*>( context );
        if ( serializeContext )
        {
            serializeContext->Class<MyFirstNetworkComponent, MyFirstNetworkComponentBase>()
                ->Version( 1 );
        }
        MyFirstNetworkComponentBase::Reflect( context );
    }

    MyFirstNetworkComponent::MyFirstNetworkComponent()
        : m_uptimeChanged( [this]( double uptime ) { OnUpTimeChanged( uptime ); } )
    {
    }

    void MyFirstNetworkComponent::OnActivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
    {
        if (HasController() == false) // client only
        {
            UpTimeAddEvent( m_uptimeChanged );
        }
    }

    void MyFirstNetworkComponent::OnDeactivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
    {
    }

    void MyFirstNetworkComponent::OnUpTimeChanged( double uptime )
    {
        AZ_Printf( "MyFirstNetworkComponent", "client = %f", uptime );
    }

    /////////// Controller ////////////////

    MyFirstNetworkComponentController::MyFirstNetworkComponentController( MyFirstNetworkComponent& parent )
        : MyFirstNetworkComponentControllerBase( parent )
    {
    }

    void MyFirstNetworkComponentController::OnActivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
    {
        AZ::TickBus::Handler::BusConnect();
    }

    void MyFirstNetworkComponentController::OnDeactivate( [[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating )
    {
        AZ::TickBus::Handler::BusDisconnect();
    }

    void MyFirstNetworkComponentController::OnTick( [[maybe_unused]] float deltaTime, AZ::ScriptTimePoint time )
    {
        ModifyUpTime() = time.GetSeconds();
        AZ_Printf( "MyFirstNetworkComponent", "server = %f", GetUpTime() );
    }
}

我们的代码生成 xml 文件 <o3de-multiplayersample>\Gem\Code\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.xml需要是：

<?xml version="1.0"?>
<Component Name="MyFirstNetworkComponent"
        Namespace="MultiplayerSample"
        OverrideComponent="true"
        OverrideController="true"
        OverrideInclude="Source/Components/MyFirstNetworkComponent.h"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<NetworkProperty Type="double"
                Name="UpTime"
                Init="0.0"
                ReplicateFrom="Authority"
                ReplicateTo="Client"
                IsRewindable="true"
                IsPredictable="true"
                IsPublic="true"
                Container="Object"
                ExposeToEditor="false"
                ExposeToScript="false"
                GenerateEventBindings="true"
                Description="Time since the start of the application" />
</Component>

现在我们在 server 和 client logic之间实现了清晰的分离。

添加远程过程调用

现在，我们已经使用网络属性创建了从服务器到客户端的数据流，我们将添加远程过程调用（RPC）。每当客户端获得新的UpTime 时，它都会调用新的 RPC - SendConfirmUptime，并将其获取的值发送回服务器。只是为了好玩。

添加定义 RPC 的 codegen 部分：

<RemoteProcedure Name="SendConfirmUptime"
                InvokeFrom="Autonomous"
                HandleOn="Authority"
                IsPublic="false"
                IsReliable="false"
                GenerateEventBindings="false"
                Description="Uptime confirmed by the client">
    <Param Type="double"
        Name="UpTime" />
</RemoteProcedure>

请注意，InvokeFrom 是 ‘Autonomous’ 而不是 ‘Client’。’Autonomous‘是一种特殊类型的客户端行为，其中客户端启动操作并可能将数据发送到服务器。

Autonomous通常用于玩家角色控制器;在这种情况下，玩家必须能够自行操作，而无需等待服务器告诉它该做什么。同时，‘Client’ 只镜像服务器告诉他们做什么。

默认情况下，只有玩家Prefab被标记为 Autonomous，因此在本教程中，我们将MyFirstNetworkComponent移动到玩家Prefab。
重要:
只有自治的实体才会有控制器，否则GetController()将在客户端上给出 null。如果您在GetController调用中得到 null，则您已将组件附加到非自治实体。请改为将它们附加到玩家Prefab，因为这些Prefab被服务器标记为自主。
您可以在 <o3de-multiplayersample>\Prefabs\Player.prefab 中找到 MultiplayerSample 项目的玩家Prefab。要修改Player.prefab，执行以下操作：
1. 在关卡中临时实例化玩家Prefab。（您可以在 <o3de-multiplayersample>\Prefabs\Player.prefab 中找到 MultiplayerSample 项目的玩家Prefab。
2. 通过将 MyFirstNetworkComponent 添加到 player 实体来修改玩家Prefab实例。
3. 保存播放器Prefab。
4. 从关卡中删除玩家Prefab。
重新构建MultiplayerSample.Static项目。您会注意到，为我们的组件生成的头文件\path\to\o3de\build\MultiplayerSample-6db9bd97\Gem\Code\Azcg\Generated\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.h 在MyFirstNetworkComponentController的大注释块中有一个新的空虚拟方法：
注意:
您可能会被此文件夹名称MultiplayerSample-6db9bd97抛出。这是 build 文件夹中的代码生成的文件夹。您的 build 文件夹中可能有不同的名称。
```
class MyFirstNetworkComponentController
...

    void HandleSendConfirmUptime(AzNetworking::IConnection* invokingConnection, const double& UpTime) override {}
```

请注意这一点，并提供以下HandleSendConfirmUptime的实现：

void MyFirstNetworkComponentController::HandleSendConfirmUptime([[maybe_unused]] AzNetworking::IConnection* invokingConnection,
    const double& upTime)
{
    AZ_Printf("MyFirstNetworkComponent", "on server - client told us about %f\n", upTime);
}

客户端将引用其控制器来调用 RPC：

void MyFirstNetworkComponent::OnUpTimeChanged(double uptime)
{
    AZ_Printf("MyFirstNetworkComponent", "client = %f\n", uptime);
    static_cast<MyFirstNetworkComponentController*>(GetController())->SendConfirmUptime(uptime);
}

最后，向MyFirstNetworkComponentController::OnActivate添加一个检查，以确保 MyFirstNetworkComponentController在服务器上执行时仅连接到TickBus，而不是自治玩家客户端：

void MyFirstNetworkComponentController::OnActivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
{
    if (!IsAutonomous())
    {
        AZ::TickBus::Handler::BusConnect();
    }
}

您的组件源代码应如下所示\path\to\MultiplayerSample\Gem\Code\Source\Components\MyFirstNetworkComponent.h:

#pragma once

#include <Source/AutoGen/MyFirstNetworkComponent.AutoComponent.h>
#include <AzCore/Component/TickBus.h>

namespace MultiplayerSample
{
    class MyFirstNetworkComponent
        : public MyFirstNetworkComponentBase
    {
    public:
        AZ_MULTIPLAYER_COMPONENT( MultiplayerSample::MyFirstNetworkComponent, s_myFirstNetworkComponentConcreteUuid, MultiplayerSample::MyFirstNetworkComponentBase );

        static void Reflect( AZ::ReflectContext* context );

        MyFirstNetworkComponent();

        void OnInit() override {}
        void OnActivate( Multiplayer::EntityIsMigrating entityIsMigrating ) override;
        void OnDeactivate( Multiplayer::EntityIsMigrating entityIsMigrating ) override;

    private:
        AZ::Event<double>::Handler m_uptimeChanged;
        void OnUpTimeChanged( double uptime );
    };

    class MyFirstNetworkComponentController
        : public MyFirstNetworkComponentControllerBase
        , public AZ::TickBus::Handler
    {
    public:
        MyFirstNetworkComponentController(MyFirstNetworkComponent& parent);

        void OnActivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;
        void OnDeactivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;

        void OnTick( float deltaTime, AZ::ScriptTimePoint time ) override;

        void HandleSendConfirmUptime(AzNetworking::IConnection* invokingConnection, const double& UpTime) override;
    };
}

并且源文件 \path\to\MultiplayerSample\Gem\Code\Source\Components\MyFirstNetworkComponent.cpp应为：

#include <Source/Components/MyFirstNetworkComponent.h>

#include <AzCore/Serialization/SerializeContext.h>
#include <Multiplayer/Components/NetBindComponent.h>

namespace MultiplayerSample
{
    void MyFirstNetworkComponent::Reflect(AZ::ReflectContext* context)
    {
        AZ::SerializeContext* serializeContext = azrtti_cast<AZ::SerializeContext*>(context);
        if (serializeContext)
        {
            serializeContext->Class<MyFirstNetworkComponent, MyFirstNetworkComponentBase>()
                ->Version(1);
        }
        MyFirstNetworkComponentBase::Reflect(context);
    }

    MyFirstNetworkComponent::MyFirstNetworkComponent()
        : m_uptimeChanged([this](double uptime) { OnUpTimeChanged(uptime); })
    {
    }

    void MyFirstNetworkComponent::OnActivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
    {
        if (IsNetEntityRoleAutonomous())
        {
            UpTimeAddEvent(m_uptimeChanged); // listen only on clients
        }
    }

    void MyFirstNetworkComponent::OnDeactivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
    {
    }

    void MyFirstNetworkComponent::OnUpTimeChanged(double uptime)
    {
        AZ_Printf("MyFirstNetworkComponent", "client = %f\n", uptime);
        static_cast<MyFirstNetworkComponentController*>(GetController())->SendConfirmUptime(uptime);
    }

    /////////// Controller ////////////////

    MyFirstNetworkComponentController::MyFirstNetworkComponentController(MyFirstNetworkComponent& parent)
        : MyFirstNetworkComponentControllerBase(parent)
    {
    }

    void MyFirstNetworkComponentController::OnActivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
    {
        if (!IsAutonomous())
        {
            AZ::TickBus::Handler::BusConnect();
        }
    }

    void MyFirstNetworkComponentController::OnDeactivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
    {
        AZ::TickBus::Handler::BusDisconnect();
    }

    void MyFirstNetworkComponentController::OnTick([[maybe_unused]] float deltaTime, AZ::ScriptTimePoint time)
    {
        ModifyUpTime() = time.GetSeconds();
        AZ_Printf("MyFirstNetworkComponent", "server = %f\n", GetUpTime());
    }

    void MyFirstNetworkComponentController::HandleSendConfirmUptime([[maybe_unused]] AzNetworking::IConnection* invokingConnection,
        const double& upTime)
    {
        AZ_Printf("MyFirstNetworkComponent", "on server - client told us about %f\n", upTime);
    }
}

我们用于代码生成器的 xml，<o3de-multiplayersample>\Gem\Code\Source\AutoGen\MyFirstNetworkComponent.AutoComponent.xml:

<?xml version="1.0"?>
<Component Name="MyFirstNetworkComponent"
        Namespace="MultiplayerSample"
        OverrideComponent="true"
        OverrideController="true"
        OverrideInclude="Source/Components/MyFirstNetworkComponent.h"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<NetworkProperty Type="double"
                Name="UpTime"
                Init="0.0"
                ReplicateFrom="Authority"
                ReplicateTo="Client"
                IsRewindable="true"
                IsPredictable="true"
                IsPublic="true"
                Container="Object"
                ExposeToEditor="false"
                ExposeToScript="false"
                GenerateEventBindings="true"
                Description="Time since the start of the application" />
<RemoteProcedure Name="SendConfirmUptime"
                InvokeFrom="Autonomous"
                HandleOn="Authority"
                IsPublic="false"
                IsReliable="false"
                GenerateEventBindings="false"
                Description="Uptime confirmed by the client">
    <Param Type="double"
        Name="UpTime" />
</RemoteProcedure>
</Component>

此时，在 Play Mode 下运行游戏时，您应该会看到 Editor 控制台中发出的客户端和服务器日志：