使用cmake利用grpc库生成一个通信案例（包含服务端和客户端）

好的，下面是使用CMake利用gRPC库生成一个通信案例（包含服务端和客户端）的步骤：

1. 安装gRPC库

首先需要在本地安装gRPC库，可以参考官方文档进行安装。

2. 创建CMake项目

使用CMake创建一个新的项目，并在项目中添加以下内容：

a. CMakeLists.txt文件

在项目根目录下创建一个CMakeLists.txt文件，内容如下：

cmake_minimum_required(VERSION 3.10)

project(grpc_example)

set(CMAKE_CXX_STANDARD 11)

# Find gRPC
find_package(gRPC REQUIRED)

# Find Protobuf
find_package(Protobuf REQUIRED)

# Include generated *.pb.h files
include_directories(${CMAKE_CURRENT_BINARY_DIR})

# Generate *.pb.cc and *.pb.h files
protobuf_generate_cpp(PROTO_SRCS PROTO_HDRS
    proto/example.proto
)

# Define server source files
set(SERVER_SOURCES
    ${CMAKE_CURRENT_SOURCE_DIR}/src/server.cpp
    ${PROTO_SRCS}
)

# Define client source files
set(CLIENT_SOURCES
    ${CMAKE_CURRENT_SOURCE_DIR}/src/client.cpp
    ${PROTO_SRCS}
)

# Define server executable
add_executable(server ${SERVER_SOURCES})
target_link_libraries(server gRPC::grpc++ gRPC::grpc++_reflection protobuf::libprotobuf)

# Define client executable
add_executable(client ${CLIENT_SOURCES})
target_link_libraries(client gRPC::grpc++ gRPC::grpc++_reflection protobuf::libprotobuf)

b. example.proto文件

在项目的proto目录下创建一个example.proto文件，内容如下：

syntax = "proto3";

package example;

// Define request message
message Request {
  string message = 1;
}

// Define response message
message Response {
  string message = 1;
}

// Define service
service ExampleService {
  rpc SendMessage(Request) returns (Response) {}
}

c. server.cpp文件和client.cpp文件

在项目的src目录下分别创建一个server.cpp文件和client.cpp文件，内容如下：

server.cpp:

#include <iostream>
#include <memory>
#include <string>
#include <grpcpp/grpcpp.h>
#include "example.grpc.pb.h"

using grpc::Server;
using grpc::ServerBuilder;
using grpc::ServerContext;
using grpc::Status;
using example::Request;
using example::Response;
using example::ExampleService;

// Server implementation
class ExampleServiceImpl final : public ExampleService::Service {
public:
    Status SendMessage(ServerContext* context, const Request* request, Response* response) override {
        std::string message = "Server received: " + request->message();
        std::cout << message << std::endl;
        response->set_message(message);
        return Status::OK;
    }
};

// Main function
int main() {
    std::string server_address("0.0.0.0:50051");
    ExampleServiceImpl service;

    // Build server
    ServerBuilder builder;
    builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
    builder.RegisterService(&service);
    std::unique_ptr<Server> server(builder.BuildAndStart());

    std::cout << "Server listening on " << server_address << std::endl;

    // Wait for server to shutdown
    server->Wait();

    return 0;
}

client.cpp:

#include <iostream>
#include <memory>
#include <string>
#include <grpcpp/grpcpp.h>
#include "example.grpc.pb.h"

using grpc::Channel;
using grpc::ClientContext;
using grpc::Status;
using example::Request;
using example::Response;
using example::ExampleService;

// Client implementation
class ExampleClient {
public:
    ExampleClient(std::shared_ptr<Channel> channel) : stub_(ExampleService::NewStub(channel)) {}

    std::string SendMessage(const std::string& message) {
        Request request;
        request.set_message(message);

        Response response;
        ClientContext context;

        // Call server
        Status status = stub_->SendMessage(&context, request, &response);

        if (status.ok()) {
            return response.message();
        } else {
            return "RPC failed";
        }
    }

private:
    std::unique_ptr<ExampleService::Stub> stub_;
};

// Main function
int main() {
    std::string server_address("0.0.0.0:50051");

    // Create client
    ExampleClient client(grpc::CreateChannel(server_address, grpc::InsecureChannelCredentials()));

    // Call server method
    std::string response = client.SendMessage("Hello from client!");
    std::cout << "Server responded with: " << response << std::endl;

    return 0;
}

3. 构建项目

在项目根目录下执行以下命令构建项目：

mkdir build
cd build
cmake ..
make

4. 运行项目

在build目录下执行以下命令启动服务端：

./server

在另一个终端窗口下执行以下命令运行客户端：

./client

客户端将会向服务端发送一条消息，并在控制台上输出服务端的回复消息。