float 怎样转换成字符串

[mian_bao]

我用MFC写了一个计算器，计算结果为float类型，怎样把它转换成字符类型输出在EDIT 的编辑框中？？

[healer_kx]

sprintf.....

[coverallwangp]

itoa()函数

或者利用ASCII码的值，自己写个转换函数

[healer_kx]

MFC啊，那就

CString::Format("%f", 3.14);

[coverallwangp]

[Quote=引用 3 楼 healer_kx 的回复:]
MFC啊，那就

CString::Format("%f", 3.14);
[/Quote]

[xingshi8000]

sprintf()

[Lilly56]

结果：float fdata;
EDIT：CString m_Data；

fdata = 3.1415926；
m_Data.Format("%f",fdata);

[sunhuanwen]

就像3楼那样

CString str;
str.Format("%f", 3.1415....);

[xzdwfwt111]

char a[];
sprintf(a,"%d",int);

[cumtxxl]

将控件绑定一个CString 类型的变量 strResult
strResult.format("%f",theFloatDate);

[Xshl5]

方法一:

sprintf
函数原型:

int sprintf(
   char *buffer,
   const char *format [,
      argument] ... 
);

调用:

...
char str[20]="";
double d=3.1415926535;
sprintf(str,"%f",d);

fwrite(str,1,strlen(str),fp);  // 将其写如文件流fp
...

方法二:
直接将浮点值转化成字符串类型，有如下三个函数：
_CRTIMP char* __cdecl ecvt (double, int, int*, int*);
_CRTIMP char* __cdecl fcvt (double, int, int*, int*);
_CRTIMP char* __cdecl gcvt (double, int, char*);

在这里用 _gcvt比较合适，

char *_gcvt( 
   double value,
   int digits,
   char *buffer 
);

MSDN的例子：

// crt_gcvt.c
// compile with: /W1
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int main( void )
{
   char buffer[_CVTBUFSIZE];
   double value = -1234567890.123;
   printf( "The following numbers were converted by _gcvt(value,12,buffer):\n" );
   _gcvt( value, 12, buffer ); // C4996
   // Note: _gcvt is deprecated; consider using _gcvt_s instead
   printf( "buffer: '%s' (%d chars)\n", buffer, strlen(buffer) );
   value *= 10;
   _gcvt( value, 12, buffer ); // C4996
   printf( "buffer: '%s' (%d chars)\n", buffer, strlen(buffer) );
   value *= 10;
   _gcvt( value, 12, buffer ); // C4996
   printf( "buffer: '%s' (%d chars)\n", buffer, strlen(buffer) );
   value *= 10;
   _gcvt( value, 12, buffer ); // C4996
   printf( "buffer: '%s' (%d chars)\n", buffer, strlen(buffer) );

   printf( "\n" );
   value = -12.34567890123;
   _gcvt( value, 12, buffer ); // C4996
   printf( "buffer: '%s' (%d chars)\n", buffer, strlen(buffer) );
   value /= 10;
   _gcvt( value, 12, buffer ); // C4996
   printf( "buffer: '%s' (%d chars)\n", buffer, strlen(buffer) );
   value /= 10;
   _gcvt( value, 12, buffer ); // C4996
   printf( "buffer: '%s' (%d chars)\n", buffer, strlen(buffer) );
   value /= 10;
   _gcvt( value, 12, buffer ); // C4996
   printf( "buffer: '%s' (%d chars)\n", buffer, strlen(buffer) );
}
 
---------------------------------------------------------
// Output
  
The following numbers were converted by _gcvt(value,12,buffer):
buffer: '-1234567890.12' (14 chars)
buffer: '-12345678901.2' (14 chars)
buffer: '-123456789012' (13 chars)
buffer: '-1.23456789012e+012' (19 chars)

buffer: '-12.3456789012' (14 chars)
buffer: '-1.23456789012' (14 chars)
buffer: '-0.123456789012' (15 chars)
buffer: '-1.23456789012e-002' (19 chars)
 

[XiaoG602]

[code=C/C++][/
#include <sstream>
#include <iostream>
using namespace std;
int main()
{
stringstream ss;
string str;
double a=3.14;
ss<<a;
ss>>str;
cout<<str;
return 0;
}
]

[mian_bao]

有这么多方法!~!我就用_gcvt了,11楼的方法也挺新鲜的.
谢谢大家

[tangshuiling]

支持一下，MARK