UE4 Sockets多线程TCP通信

一、简介

UE4引擎是提供了Sockets模块和Networking模块的，博主在研究此功能时也是参考的Sockets模块和Networking模块的源码，其中引擎为我们提供了一些实例类很有参考价值，比如Sockets模块中的MultichannelTcpReceiver.h和MultichannelTcpSender.h，Networking模块中的UdpSocketReceiver.h和UdpSocketSender.h。博主的例子就是研究参考了以上代码写出来的。

编译与运行环境

UnrealEngine 4.15 ， Visual Studio 2015

实现功能介绍

博主的例子实现的是一个使用Socket多线程TCP通信的客户端。在主线程中发消息，子线程中收消息。当然也能类似的实现两个子线程分别收发消息。Socket相关函数都定义在了GameInstance中，以便我们能在不同场景都能调用。

二、代码实现

服务器代码

此处使用了一个有简单收发功能的服务器，用VS2015新建空项目即可：

//SocketTest.cpp: Defines the entry point for the console application #include <stdio.h> #include <string> #include <iostream> #include <WinSock2.h> #include <WS2tcpip.h> #pragma comment(lib, "WS2_32.lib") using namespace std; int main() { WSADATA wsaData; SOCKET serverSock; SOCKADDR_IN serverAddr; SOCKET clientSock; SOCKADDR_IN clientAddr; cout << "Server Start!" << endl; //加载套接字库 int err = WSAStartup(MAKEWORD(2, 2), &wsaData); if (0 != err) { cout << "WSAStartup failed!" << endl; return 1; } //构造监听SOCKET，流式SOCKET serverSock = socket(AF_INET, SOCK_STREAM, 0); //配置监听地址和端口 serverAddr.sin_family = AF_INET; serverAddr.sin_port = htons(4399); //本地监听端口：4399 serverAddr.sin_addr.S_un.S_addr = INADDR_ANY; //绑定SOCKET int retVal = bind(serverSock, (SOCKADDR*)&serverAddr, sizeof(serverAddr)); if (SOCKET_ERROR == retVal) { cout << "bind failed!" << endl; closesocket(serverSock); WSACleanup(); return -1; } retVal = listen(serverSock, 5); if (SOCKET_ERROR == retVal) { cout << "listen failed!" << endl; closesocket(serverSock); WSACleanup(); return -1; } char IPdot[20] = { '\0' }; inet_ntop(AF_INET, (void*)&serverAddr.sin_addr, IPdot, 16); printf("Welcome,the Host %s is running!Now Wating for someone comes in!\n", IPdot); int addrClientlen = sizeof(clientAddr); //等待客户端连接 clientSock = accept(serverSock, (SOCKADDR*)&clientAddr, &addrClientlen); while (1) { //发送数据 char sendBuff[50]; //sprintf_s(sendBuff, "welcome %s to here", inet_ntoa(clientAddr.sin_addr)); char IPdotdec[20] = { '\0' }; inet_ntop(AF_INET, (void*)&clientAddr.sin_addr, IPdotdec, 16); sprintf_s(sendBuff, "From Server: welcome %s to here", IPdotdec); send(clientSock, sendBuff, strlen(sendBuff) + 1, 0); //接收数据 char recvBuff[50]; recv(clientSock, recvBuff, 50, 0); printf(" %s \n\n", recvBuff); Sleep(1000); } //关闭套接字，关闭加载的套接字库 closesocket(serverSock); WSACleanup(); return 0; }

模块添加

新建项目，在.Build.cs文件中添加Sockets模块和Networking模块：

// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved. using UnrealBuildTool; public class SocketThread : ModuleRules { public SocketThread(TargetInfo Target) { PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "HeadMountedDisplay","Sockets", "Networking" }); } }

Socket相关函数定义

STGameInstance.h

//this is the STGameInstance.h #pragma once #include "Engine/GameInstance.h" #include "Networking.h" #include "ReceiveThread.h" #include "STGameInstance.generated.h" UCLASS() class SOCKETTHREAD_API USTGameInstance : public UGameInstance { GENERATED_BODY() public: //创建Socket并连接到服务器（主线程） UFUNCTION(BlueprintCallable, Category = "MySocket") bool SocketCreate(FString IPStr, int32 port); //发消息(主线程) UFUNCTION(BlueprintCallable, Category = "MySocket") bool SocketSend(FString message); //收消息(子线程) UFUNCTION(BlueprintCallable, Category = "MySocket") bool SocketReceive(); UFUNCTION(BlueprintCallable, Category = "MySocket") bool ThreadEnd(); FString StringFromBinaryArray(TArray<uint8> BinaryArray); public: FSocket *Host; FIPv4Address ip; FRunnableThread* m_RecvThread; };

STGameInstance.cpp

//this is the STGameInstance.cpp #include "SocketThread.h" #include "STGameInstance.h" bool USTGameInstance::SocketCreate(FString IPStr, int32 port) { FIPv4Address::Parse(IPStr, ip); //将传入的IPStr转为IPv4地址 //创建一个addr存放ip地址和端口 TSharedPtr<FInternetAddr> addr = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM)->CreateInternetAddr(); addr->SetIp(ip.Value); addr->SetPort(port); //创建客户端socket Host = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM)->CreateSocket(NAME_Stream, TEXT("default"), false); //连接成功 if (Host->Connect(*addr)) { UE_LOG(LogTemp, Warning, TEXT("Connect Succeed!")); return true; } //连接失败 else { UE_LOG(LogTemp, Warning, TEXT("Connect Failed!")); return false; } } bool USTGameInstance::SocketSend(FString message) { TCHAR *seriallizedChar = message.GetCharArray().GetData(); int32 size = FCString::Strlen(seriallizedChar) + 1; int32 sent = 0; if (Host->Send((uint8*)TCHAR_TO_UTF8(seriallizedChar), size, sent)) { UE_LOG(LogTemp, Warning, TEXT("___Send Succeed!")); return true; } else { UE_LOG(LogTemp, Warning, TEXT("___Send Failed!")); return false; } } bool USTGameInstance::SocketReceive() { m_RecvThread = FRunnableThread::Create(new FReceiveThread(Host), TEXT("RecvThread")); return true; } bool USTGameInstance::ThreadEnd() { if (m_RecvThread != nullptr) { m_RecvThread->Kill(true); delete m_RecvThread; } return true; } FString USTGameInstance::StringFromBinaryArray(TArray<uint8> BinaryArray) { return FString(ANSI_TO_TCHAR(reinterpret_cast<const char*>(BinaryArray.GetData()))); }

收消息线程

ReceiveThread.h

//this is the ReceiveThread.h #pragma once #include "ThreadingBase.h" #include "Networking.h" class SOCKETTHREAD_API FReceiveThread : public FRunnable { public: FReceiveThread(FSocket* client): m_Client(client) {} ~FReceiveThread() { stopping = true; } virtual bool Init() override { stopping = false; return true; } virtual uint32 Run() override { if (!m_Client) { return 0; } TArray<uint8> ReceiveData; uint8 element = 0; //接收数据包 while (!stopping) //线程计数器控制 { ReceiveData.Init(element, 1024u); int32 read = 0; m_Client->Recv(ReceiveData.GetData(), ReceiveData.Num(), read); const FString ReceivedUE4String = FString(ANSI_TO_TCHAR(reinterpret_cast<const char*>(ReceiveData.GetData()))); FString log = "Server:" + ReceivedUE4String; UE_LOG(LogTemp, Warning, TEXT("*** %s"), *log); FPlatformProcess::Sleep(0.01f); } return 1; } virtual void Stop() override { stopping = true; //计数器-1 } private: FSocket* m_Client; //客户端套接字 bool stopping; //循环控制 FThreadSafeCounter m_StopTaskCounter; //线程引用计数器 };

三、运行

在编辑器中，创建我们之前定义的GameInstance的蓝图类，并在Project Setting中设其为默认GameInstance。创建一个GameMode，在他的EventGraph中添加如下蓝图逻辑： 其中Succe是一个bool类型变量，Index是一个Int类型变量，不改默认值。 之后将这个GameMode绑定到当前场景中，编译运行服务器，然后Play，大功告成！博主运行结果如下： 可以看到，收发消息都成功了。