简介

基于之前的文章所说， Qt6.7之后才开始支持客户端、服务端、及双向流，恰好电脑需要重装，看到Qt6.8版本就直接安装了，内容也是使用Qt6.8的版本进行编译的

客户端实现步骤

1. 安装Qt6.8, 包含GRPC功能模块

Qt 6.8安装目录下包含这两个组件就可以将.proto生成Qt库支持了

2. 基于上一篇的示例，生成Qt支持

基于 Qt6.8 GRPC功能使用(1)标准GRPC C++ exmple编译环境搭建
新建一个Qt grpc客户端应用, 将 helloworld.proto 拷贝到该应用中，.pro加上grpc支持 .pro += grpc

proto文件

.proto文件内容， 来自xxx\grpc-1.55.0\examples\protos\helloworld.proto

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

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

  rpc SayHelloStreamReply (HelloRequest) returns (stream 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;
}

生成 Proto buffer的Qt支持

D:\Softwares\Paths\msys64\mingw64\bin\protoc.exe --plugin=protoc-gen-qtprotobuf=D:\Softwares\IDEs\Qt\6.8.0\mingw_64\bin\qtprotobufgen.exe -I E:/Workspace/Qt/greeter_client_qt/grpc --qtprotobuf_out=“E:/Workspace/Qt/greeter_client_qt/grpc” “E:/Workspace/Qt/greeter_client_qt/grpc/helloworld.proto”

生成 GRPC 的Qt支持

D:\Softwares\Paths\msys64\mingw64\bin\protoc.exe --plugin=protoc-gen-qtgrpc=D:\Softwares\IDEs\Qt\6.8.0\mingw_64\bin\qtgrpcgen.exe -I E:/Workspace/Qt/greeter_client_qt/grpc --qtgrpc_out=“E:/Workspace/Qt/greeter_client_qt/grpc” “E:/Workspace/Qt/greeter_client_qt/grpc/helloworld.proto”

3. 增加client代码

#include <QCoreApplication>
#include <QGrpcChannelOptions>
#include <QGrpcServerStream>
#include "helloworld_client.grpc.qpb.h"
#include <QGrpcHttp2Channel>
#include <QDebug>


int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    helloworld::Greeter::Client client;

    QAbstractSocket::connect(&client, &QAbstractGrpcClient::errorOccurred, [=](const QGrpcStatus &status)
    {
        qDebug().noquote() << "errorOccurred : " << status.code() << status.message();
    });
    QAbstractSocket::connect(&client, &QAbstractGrpcClient::channelChanged, [=]()
    {
        qDebug().noquote() << "channelChanged!";
    });

    QUrl url ("http://localhost:50051");
    QGrpcChannelOptions channelOptions(url);
    std::shared_ptr<QAbstractGrpcChannel> channel = std::make_shared<QGrpcHttp2Channel>(
        channelOptions);
    client.attachChannel(channel);

    helloworld::HelloRequest req;
    req.setName("GrayHsu");

    std::shared_ptr<QGrpcCallReply> grpcReply = client.SayHello(req);
    QAbstractSocket::connect(grpcReply.get(), &QGrpcCallReply::errorOccurred, [=](const QGrpcStatus &status)
    {
        qDebug().noquote() << "sayHello errorOccurred : " << status.code() << status.message();
    });
    QAbstractSocket::connect(grpcReply.get(), &QGrpcCallReply::finished, [=]()
    {
        helloworld::HelloReply rep;
        grpcReply->read(&rep);
        qDebug().noquote() << "finished: " << rep.message();
    });
    return a.exec();
}

执行结果:
Server 没开

Server开了

4. Qt库简单说明

QGrpcCallReply用于接收返回信息, 提供了两个信号, 用于监控是否出错及是否结束(流时则为关闭)
std::shared_ptr grpcReply = client.SayHello(req);

Note

.proto 文件生成protobuffer和支持grpc语言文件支持指令

例如:

如下指令直接生成grpc_out的grpc支持，-cpp_out输出protobuffer支持
	D:\Softwares\Paths\msys64\mingw64\bin\protoc.exe --grpc_out E:/test/grpc-1.55.0/examples/cpp/helloworld/cmake/build --cpp_out E:/test/grpc-1.55.0/examples/cpp/helloworld/cmake/build -I E:/test/grpc-1.55.0/examples/protos --plugin=protoc-gen-grpc="D:/Softwares/Paths/msys64/mingw64/bin/grpc_cpp_plugin.exe" E:/test/grpc-1.55.0/examples/protos/helloworld.proto