Qt gRPC 簡單應用 原

Qt 想在windows下運行起grpc服務簡直天坑，在數十次失敗後，用以下方法運行成功。

通過以下網址下載msys2 64位版（32位在windows 10上沒跑起來）:

https://www.msys2.org/

安裝完成後，在開始菜單找到並運行“MSYS2 MSYS”，在命令框運行以下命令(10M光纖下載安裝了兩個多小時，請耐心等待)：

pacman -Syu

pacman -S mingw-w64-x86_64-grpc mingw-w64-x86_64-qt mingw-w64-x86_64-qt-creator

pacman -S mingw-w64-x86_64-clang

pacman -S mingw-w64-x86_64-qt5-static

“安裝盤\msys64\mingw64\bin” 加下環境變量Path裏。

運行msys64\mingw64\bin\qtcreator.exe，啓動QtCreator，新建Console項目(命名爲QtgRPCConsole)。

爲避免以下錯誤：

配置文件里加入：

DEFINES += _WIN32_WINNT=0x600

右擊項目選擇“添加庫...->外部庫”，指向“msys64\mingw64\lib\libgrpc.dll.a”，取消"爲debug版本添加‘d’作爲後綴"的複選框選項，完成後如下圖：

增加其他grpc和protobuffer庫名到配置文件：

unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc_cronet.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc_csharp_ext.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc_plugin_support.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc_unsecure.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc++.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc++_cronet.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc++_error_details.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc++_reflection.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibgrpc++_unsecure.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibprotobuf.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibprotobuf-lite.dll
unix|win32: LIBS += -LD:/msys64/mingw64/lib/ -llibprotoc.dll

INCLUDEPATH += D:/msys64/mingw64/include
DEPENDPATH += D:/msys64/mingw64/include

新建protobuffer文件helloworld.proto：

syntax = "proto3";

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
  string name = 1;
}

// The response message containing the greetings
message HelloReply {
  string message = 1;
}

通過protoc生成gRPC類（從mingw/bin下拷貝grpc_cpp_plugin.exe到項目目錄下面）：

protoc -I ./ --grpc_out=./ --plugin=protoc-gen-grpc=grpc_cpp_plugin.exe ./helloworld.proto
protoc -I ./  --cpp_out=./ ./helloworld.proto

右擊項目“添加現有文件...”選擇生成的grpc頭文件和類（helloworld.grpc.pb.cc、helloworld.pb.cc、helloworld.grpc.pb.h、helloworld.pb.h）到項目中。

編寫服務端代碼：

#include <QCoreApplication>

#include <iostream>
#include <memory>
#include <string>

#include <grpc++/grpc++.h>
#include "helloworld.pb.h"
#include "helloworld.grpc.pb.h"

using grpc::Server;
using grpc::ServerBuilder;
using grpc::ServerContext;
using grpc::Status;
using helloworld::HelloRequest;
using helloworld::HelloReply;
using helloworld::Greeter;

// Logic and data behind the server's behavior.
class GreeterServiceImpl final : public Greeter::Service {
  Status SayHello(ServerContext* context, const HelloRequest* request,
                  HelloReply* reply) override {
    std::string prefix("Hello ");
    reply->set_message(prefix + request->name());
    return Status::OK;
  }
};

void RunServer() {
  std::string server_address("0.0.0.0:50051");
  GreeterServiceImpl service;

  ServerBuilder builder;
  // Listen on the given address without any authentication mechanism.
  builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
  // Register "service" as the instance through which we'll communicate with
  // clients. In this case it corresponds to an *synchronous* service.
  builder.RegisterService(&service);
  // Finally assemble the server.
  std::unique_ptr<Server> server(builder.BuildAndStart());
  std::cout << "Server listening on " << server_address << std::endl;

  // Wait for the server to shutdown. Note that some other thread must be
  // responsible for shutting down the server for this call to ever return.
  server->Wait();
}

int main(int argc, char *argv[])
{
//    QCoreApplication a(argc, argv);
    RunServer();
    return 0;
}

運行結果如下：

注：在發佈版本時選擇靜態編譯，然後把grpc的動態鏈接庫放入同文件夾即可執行exe文件。