在功能包的src文件夹中新建ABC.cpp文件

打开CMakeLists.txt文件，添加如下代码

• xxx_client是节点名，rosrun package/xxx_client

    add_executable(xxx_client src/ABC.cpp)   
    target_link_libraries(xxx_client ${catkin_LIBRARIES})
    add_dependencies(xxx_client package_name_gencpp)
  

  ---

  把CMakLists.txt拉入QT

• 编写源代码，格式如下

    #include <ros/ros.h>
    #include <begin/my_srv.h>
    #include <cstdlib>
    #include<iomanip>
  
    int main(int argc, char **argv){
        ros::init(argc, argv, "client");
        ros::NodeHandle n;
        ros::ServiceClient client = n.serviceClient<begin::my_srv>("service");
        begin::my_srv srv;
        //srv包含了request和response两个成员
        //实际上可以定义为 begin::my_srv::Request req; begin::my_srv::Response rep;
        //对应的下面的调用是client.call(req,rep)
        srv.request.req = atoll(argv[1]);
        if(client.call(srv))
        {
            ROS_INFO_STREAM(srv.response.velocity.linear.x);
        }
        else
        {
            ROS_ERROR("Failed to judge!");
            return 1;
        }
    return 0;
    }