请帮我编个数据转换程序
VC++好久都没有用了，电脑上也没有装它。现在由于要调试单片机，而单片机用的是32位浮点数，与通常的习惯不一样，所以想到让大家帮忙编个程序。第一个回答问题的人将得到绝大多数分。
程序要求：IEEE的32位浮点数转16进制及十进制。（32位浮点数格式请参见http://home.eeworld.com.cn/my/space.php?uid=59045&do=blog&id=65045）
[解决办法]
看你的意思是类型装换吧？用整型惯了，浮点不适应？
搞单片机汇编什么的兄弟，看设么数据都是16进->2进制的。
你的数据 float f = 3.14f; //16进是40 48 F5 C3
转换成4字节整型 int n = (int)(f*100+0.5);
这时 n 就是整型 314 //16进是 00 00 01 3A
你是这个意思？
[解决办法]
在内存里3.14就已经是16进的40 48 F5 C3了，还转换啥呢？
你是想把它印出来？下面代码
union {
float pi;
int i4;
}u;
u.pi = 3.14;
char str[64];
sprintf(str,"%x",u.i4);
这时这个串str里面就是字符串 4048F5C3，是这个意思？
[解决办法]
哦，原来你是不会写对话框程序啊。
那同学们有的是有闲工夫的。
[解决办法]
// I3e.cpp : Defines the entry point for the console application.
//
// Floating-point numbers use the IEEE (Institute of Electrical and Electronics Engineers) format.
// Single-precision values with float type have 4 bytes, consisting of a sign bit,
// an 8-bit excess-127 binary exponent, and a 23-bit mantissa.
// The mantissa represents a number between 1.0 and 2.0.
// Since the high-order bit of the mantissa is always 1,
// it is not stored in the number.
// You can declare variables as float or double, depending on the needs of your
// application. The principal differences between the two types are
// the significance they can represent, the storage they require, and their range.
// Table 3.3 shows the relationship between significance and storage requirements.
// Table 3.3:
//TypeSignificant digits,Number of bytes
//float6 74
//double15168
// Floating-point variables are represented by a mantissa,
// which contains the value of the number, and an exponent,
// which contains the order of magnitude of the number.
// Table 3.4 shows the number of bits allocated to the mantissa
// and the exponent for each floating-point type. The most significant bit
// of any float or double is always the sign bit. If it is 1, the number is
// considered negative; otherwise, it is considered a positive number.
// Table 3.4 :
// TypeExponent length,Mantissa length
// float8 bits23 bits
// double11 bits52 bits
// Because exponents are stored in an unsigned form,
// the exponent is biased by half its possible value. For type float,
// the bias is 127; for type double, it is 1023. You can compute the
// actual exponent value by subtracting the bias value from the exponent value.
// The mantissa is stored as a binary fraction greater than or equal to 1
// and less than 2. For types float and double, there is an implied leading 1
// in the mantissa in the most-significant bit position, so the mantissas are
// actually 24 and 53 bits long, respectively, even though the most-significant bit
// is never stored in memory.
// Intel IEEE 格式: S(1bit) E(8bit) M(23bit)
// Microsoft MBF 格式: E(8bit) S(1bit) M(23bit)
#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//
union IEEE
{
float f;// 微软浮点格式.与 INTEL 浮点格式(IEEE)不同
int i;
unsigned int dw;// 2 words
} ;
//
void MBF(IEEE f)
{
IEEE nf;
char bit[80];
if(f.dw != 0)
{
unsigned int sign = f.dw & 0x80000000;
unsigned int exp = f.dw & 0x7F800000;
unsigned int mantissa= f.dw & 0x007FFFFF;
nf.dw=0;
nf.dw = exp << 1;
nf.dw |= sign >> 8;
nf.dw |= mantissa;
itoa(nf.i,bit,2);
int len=strlen(bit);
if(len !=32)
{
strrev(bit);
for(int jj=0;jj<(32-len);jj++)
{
strcat(bit,"0");
}
strrev(bit);
}
printf("MBF: %f = %32s = %08X\n",f.f,bit,nf.i);
}
}
//
int main(int argc, char* argv[])
{
IEEE xxx;
char bit[80];
//int *P;
//P=(int*)0x100;
for (int jj=0;jj<10;jj++)
{
xxx.f=(float)jj/8;// change this for other data
itoa(xxx.i,bit,2);//整数转换为二进制字串
strrev(bit);// 翻转字串
unsigned int len=strlen(bit);
for (int jj=0;jj<(int)(32-len);jj++)
{// 补零
strcat(bit,"0");
}
strrev(bit);// 恢复
printf("%f = %32s = %08X\n",xxx.f,bit,xxx.i);
// 再计算回来
if(xxx.f!=0)
{// xxx.dw ==0 时, 规定 xxx.f 为0
char sign=xxx.dw & 0x80000000 ? '-' : '+';// 最高位是符号位
int exp=(xxx.dw & 0x7F800000)>>23;//以后8位是指数部分,要减127
float mantissa=(float)(xxx.dw & 0x007FFFFF)/0x007FFFFF+1;//+1 隐藏的
printf("Sign=%C,Exponent=2^%d,mantissa=%f\n",sign,exp-127,mantissa);
}
}
//
float y=0.0;
for(;;)
{
printf ("输入一个浮点数, 输入字符退出.\n");
if (scanf("%f",&y)==0) return 1;
xxx.f=(float)y;// change this for other data
itoa(xxx.i,bit,2);//整数转换为二进制字串
strrev(bit);// 翻转字串
unsigned int len=strlen(bit);
for (int jj=0;jj<(int)(32-len);jj++)
{// 补零
strcat(bit,"0");
}
strrev(bit);// 恢复
MBF(xxx);
printf("I3E: %f = %32s = %08X\n",xxx.f,bit,xxx.i);
}
//
return 0;
}