VC中的字符串操作

VC中的字符串操作

//本文内容: 1.字符串的连接; 2.字符串数组的赋值; 3.LPWSTR,BSTR中字符串(含中文)的显示;4.数据转换;

#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include "iostream.h"
#include "comutil.h"
#include <comdef.h>
#pragma comment( lib, "comsupp.lib" )
#define   LEN   100
//字符串的连接
BOOL getValue()
{
    char buffer2[100];
    _bstr_t s,s2;   
    s = L"S7:[S7 connection_1]DB90,X" ;
    float f=0.0f;
    char  *p,*p2;
    //p=(char *)malloc(100);
    p=new char[100];
    p2="1234";
    strcpy(p,"S7:[S7 connection_1]DB90,X");
    //p="S7:[S7 connection_1]DB90,X" ;
    BOOL Flag=TRUE;
    for(int j1=0;j1<68;j1++)
    {
        
        sprintf( buffer2, "%0.1f",f);
        //cout<<"buffer2="<<buffer2<<endl;
        LPWSTR lps;
        if(Flag)
        {
        s2=s+buffer2;
        //cout<<endl<<s+buffer2<<endl;
        //cout<<endl<<s2<<endl;
        lps=::SysAllocString(s2);
        //cout<<"  lps="<<lps<<endl;
        }
        else
        {
        p2=buffer2;
        strcpy(p,"S7:[S7 connection_1]DB90,X");

    //    char *p3="123";
    //        char *p23="123";
    //        int *i=NULL;
    //        int j=100;    
    //        i=&j;
    //        cout<<"i="<<i<<endl;
    //        cout<<"p3="<<p3<<endl;
    //        if(p3==p23)
    //    //    if("aa"=="aa")
    //        {
    //            cout<<"true";
    //        }
    //        else
    //        {
    //            cout<<"false";
    //        }
    
        strcat(p,p2);
        lps=_com_util::ConvertStringToBSTR(p) ;
        }
        //cout<<"编号: "<<j1<<" 地址连接符: ";
        wprintf(L"%3d. %s\n", j1,lps);
        f+=0.1f;
    }
    return true;
}

//应用字符串连接
int printstr()
{

 
    char str[]="ABCDE";
    char *string="ABCDE";
 
    string =(char *)malloc(LEN);
    strcpy(string,"123456");
    cout << endl;
    cout <<"字符串输出str[]="<<str<<endl;
    cout <<"字符串输出*string="<<string<<endl;
    char *AppendStr;      
    AppendStr="abc";
    
        for(int i  =   0;  i<   5; i++)   
        {   
            AppendStr=str;//"456";
            
        
            strcat(string ,AppendStr);

            //strcat(string,   "a");   
        }   
        printf("%s\n",   string);   
        
        free(string);   
         
        getchar();   


    
    return 1;
    
}



int main(void)
{
//printstr();
//system("PAUSE");


if(getValue())
cout<<"赋值成功"<<endl;
system("PAUSE");

    //通过sprintf函数进行数据类型转换
    char  buffer2[200];
    char  c = '1';
    int   i = 35;
    long  j = 1000;
    float f = 1.7320534f;
    sprintf( buffer2, "%c",c);
    sprintf( buffer2, "%d",i);
    sprintf( buffer2, "%d",j);
    //字符串的相加  
    _bstr_t s,s2;   
    s = L"S7:[S7 connection_1]DB90,X" ;
    f=0.0f;
    
    for(int j1=0;j1<100;j1++)
    {
        f+=0.1f;
        sprintf( buffer2, "%0.1f",f);
        cout<<"buffer2="<<buffer2<<endl;
        s2=s+buffer2;
        //cout<<endl<<s+buffer2<<endl;
        cout<<endl<<s2<<endl;
        BSTR bs=::SysAllocString(s2);
        LPWSTR lps=::SysAllocString(s2);
        cout<<"bs="<<bs<<"  lps="<<lps<<endl;
        wprintf(L"%s\n", bs); //显示赋值结果
        wprintf(L"%s\n", lps);
    }
    
    wchar_t *wsir;//#include<comdef.h>
    _bstr_t str=L"How are you,北京!";
    wsir=str;
    wprintf(L"%s\n", wsir);

    //中文字符的显示
    //说明:Converts a sequence of multibyte characters to a corresponding sequence of wide characters.
    //原型:size_t mbstowcs(     wchar_t* wcstr, const char* mbstr, size_t count );
    //参数:Parameters
    //      wcstr
    //        The address of a sequence of wide characters.
    //        mbstr
    //        The address of a sequence of multibyte characters.
    //        count
    //        The number of multibyte characters to convert.
         
        
    char* a = "你好,北京";
    wchar_t *b = new wchar_t[3];
    mbstowcs(b, a, sizeof(a)+1);  
    puts(a);
    wprintf(L"%s\n", b);
    system("PAUSE"); //暂停程序的执行
    LPWSTR lps=L"success   OK";     
    cout<<"lps="<<lps<<endl;    
    cout<<"*string2"<<endl;    
    char *string2[10];
    int ii=0;

    //字符串数组赋值
    cout<<endl;
    for( ii=0;ii<10;ii++)
    {
        int i=ii;
        string2[i]=new char;
        itoa(i,string2[i],10);
    }
    cout<<endl;
    for(ii=0;ii<10;ii++)
        cout<<string2[ii]<<endl;

    //把双精度数转换成一个字符串。
    //char *ecvt(double value,int count,int *dec,int *sign);
    //函数 需要的头文件 兼容性
    //ecvt <stdlib.h>   Win 95,Win NT
        
   char *string;
   double value;
   int dec=2, sign=0;
   int ndig = 1;
   //clrscr();
   value = -9.876;
   string = ecvt(value, ndig, &dec, &sign);
   printf("string = %s    dec = %d  sign = %d\n", string, dec, sign);
   value = -123.45;
   ndig= 15;
   string = ecvt(value,ndig,&dec,&sign);
   printf("string = %s dec = %d sign = %d\n",
          string, dec, sign);
   int decimal, sign2=0;
   char *buffer;

   //fcvt是将浮点数转换为字符串，它不属于标准的C运行时库，仅仅是VC提供的，
   //因此把其命名为_fcvt .
       
   float source = 0.123456f;
   buffer = _fcvt( source, 2, &decimal, &sign2 );
   //printf("%s",buffer);
   
   cout<<endl<<endl;
   cout<<buffer<<endl;
   cout<<source<<"  "<<decimal<<"  "<<sign2<<endl;
   
//运行结果:source: 3.1415926535 buffer: \\\'31415927\\\' decimal: 1 sign: 0
//decimal表示小数点的位置,sign表示符号:0为正数，1为负数

     
   return 0;
}