ROS-节点参数param

ROS中有如下3种获取参数的方式。

include "ros/ros.h" 
#include <cstdlib> 

using namespace std; 

int main(int argc,char** argv) 
{
    
     
    //initial and name node 
    ros::init(argc,argv,"node_param"); 
    if(argc!=2) 
    {
    
     
        cout<<"Error command paramter! Please run command eg:\n"\ 
            <<"rosrun book_param book_param 1\n"\ 
            <<"help information:\n"\ 
            <<" 1 ------ set param mode(ros::param::set())\n"\ 
            <<" 2 ------ set param mode(ros::NodeHandle::setParam())\n"\ 
            <<" 3 ------ get param mode(ros::param::get())\n"\ 
            <<" 4 ------ get param mode(ros::NodeHandle::getParam())\n"\ 
            <<" 5 ------ get param mode(ros::NodeHandle::param())\n"\ 
            <<endl; 
        return 1; 
    } 
    //create node handle 
    ros::NodeHandle nh; 
    //param variable 
    int IntParam; 
    string StrParam; 
    bool isIntParam, isStrParam; 
    //mode flag 
    int flag = atoi(argv[1]); 
     // set or get param with different ways 
    switch(flag) 
    {
    
     
        case 1: 
            ROS_INFO("set param mode(ros::param::set()):"); 
            ros::param::set("IntParam",1); 
            ros::param::set("StrParam","stringdemo"); 
            break; 
        case 2: 
            ROS_INFO("set param mode(ros::NodeHandle::setParam()):"); 
            nh.setParam("IntParam",1); 
            nh.setParam("StrParam","stringdemo"); 
            break; 
        case 3: 
            ROS_INFO("get param mode(ros::param::get()):"); 
            isIntParam = ros::param::get("IntParam",IntParam); 
            isStrParam = ros::param::get("StrParam",StrParam); 

            if(isIntParam){
    
     
                ROS_INFO("The IntParam is:%d",IntParam); 
            }else{
    
     
                ROS_INFO("Get IntParam fail!"); 
            } 

            if(isIntParam){
    
     
                ROS_INFO("The StrParam is:%s",StrParam.c_str()); 
            }else{
    
     
                ROS_INFO("Get StrParam fail!"); 
            } 
            break; 
        case 4: 
            ROS_INFO("get param mode(ros::NodeHandle::getParam()):"); 
            isIntParam = nh.getParam("IntParam",IntParam); 
            isStrParam = nh.getParam("StrParam",StrParam); 

            if(isIntParam){
    
     
                ROS_INFO("The IntParam is:%d",IntParam); 
            }else{
    
     
                ROS_INFO("Get IntParam fail!"); 
            } 

            if(isIntParam){
    
     
                ROS_INFO("The StrParam is:%s",StrParam.c_str()); 
            }else{
    
     
                ROS_INFO("Get StrParam fail!"); 
            } 
            break; 
        case 5: 
            ROS_INFO("get param mode(ros::NodeHandle::param()):"); 
            //warning: this way will set default value when get no param! 
            nh.param("IntParam",IntParam,11); 
            // be careful when use ros::NodeHandle::param get string param! 
            nh.param<std::string>("StrParam",StrParam,"stringdemo_default"); 
            ROS_INFO("\nThe IntParam is:%d\nThe StrParam is:%s",IntParam,StrParam.c_str()); 
            break; 
        default: 
            ROS_INFO("flag value is not in range: [1,5]"); 
    } 
    return 0;
    }