c++常用代碼

//靜態庫使用
#pragma comment(lib,"lib/NIDAQmx.lib");

//函數參數
void delay_call_func(double p_second,void(*p_func)());

//函數指針
void(*p_func)(void) p;

//四捨五入
#include <iostream>
#include <sstream>
#include <iomanip>
using namespace std;

double round(double number, unsigned int bits) {
    stringstream ss;
    ss << fixed << setprecision(bits) << number;
    ss >> number;
    return number;
}

int main() {
    double number = 3.1415926535897932;
    cout << fixed << showpoint << setprecision(15);
    cout << "一開始number = " << number << endl;

    for (int i = 0; i < 15; ++i) {
        cout << "number保留" << i << "位小數後爲: " 
            << round(number, i) << endl;
    }

    return 0;
}

//string 操作例子
//_獲取NI安裝的設備
        char	t_BufferDeviceName[10240]={0};
	DAQmxGetSysDevNames(t_BufferDeviceName, sizeof t_BufferDeviceName);
        string device(t_BufferDeviceName);
        int bj=0;
        int ej=0;
        list<string>	t_DeviceArray;
        while(ej=device.find(",",bj))
        {
                if(ej<1)
                {
                        string temp=device.substr(bj,20);
                        temp.erase(0,temp.find_first_not_of(" "));
                        temp.erase(temp.find_last_not_of(" ")+1);
                        t_DeviceArray.push_back(temp);
                        break;
                }
                string temp=device.substr(bj,ej-bj);
                temp.erase(0,temp.find_first_not_of(" "));
                temp.erase(temp.find_last_not_of(" ")+1);
                t_DeviceArray.push_back(temp);
                bj=ej+1;
                ej=0;
        }
        
        list<string>::iterator it;
        int i=0;
	for (it=t_DeviceArray.begin();it!=t_DeviceArray.end();it++)
	{
	        ComboBox1->Items->Insert(i,(*it).c_str());
                i++;
	}