RTT有浮点类型转字符串类型的函数吗

发布于 2010-08-28 18:24:59 浏览：3209 订阅该版

如题,网上找了几个,可以编译通过,但是系统起不来了.怪哉. 
```
#include "demo_view.h"
#include <rtgui/widgets/label.h>

char *itoa(int value, char *string, int radix)
{
char tmp[33];
char *tp = tmp;
int i;
unsigned v;
int sign;
char *sp;

if (radix > 36 || radix <= 1)
{
return 0;
}

sign = (radix == 10 && value < 0);
if (sign)
v = -value;
else
v = (unsigned)value;
while (v || tp == tmp)
{
i = v % radix;
v = v / radix;
if (i < 10)
*tp++ = i+'0';
else
*tp++ = i + 'a' - 10;
}

if (string == 0)
string = (char *)malloc((tp-tmp)+sign+1);
sp = string;

if (sign)
*sp++ = '-';
while (tp > tmp)
*sp++ = *--tp;
*sp = 0;
return string;
}

/*浮点数转换为字符*/ 
char* floatToString(float val, char* buf, int preci){
char *res = buf;
int tempData;

char *tempBuf;
 int backStep;
 int count;

tempData=(int)( val<0?*buf++ = '-', val=-val: val);
 itoa(tempData, buf, 10);

while(*++buf != '�'){}
 *buf++ = '.';  //将小数点添加到整数末尾

tempData=(int) ((val-(int)val) * pow(10.0, preci));//自动做了四舍五入
 itoa(tempData, buf, 10);
 tempBuf = buf;
 while(*++buf != '�'){}
 *buf = '�';
 //考虑123.0034这样的小数
 tempBuf += preci;
 if(tempBuf != buf){
 backStep = tempBuf - buf;
 for(count =  preci - backStep + 1; count != 0; count--){
 *tempBuf-- = *buf--;
 }
 for(count= backStep; count != 0; count--){
 *tempBuf-- = '0';
 }
}
 return res;
}

rtgui_view_t* test_float(rtgui_workbench_t* workbench)
{
	rtgui_rect_t rect;
	rtgui_view_t* view;
	rtgui_label_t* label;
	rtgui_font_t* font;

float num=12.5;
    char *b;
    b= (char *)rt_malloc(sizeof(char)*8);

floatToString(num,b,1);
	
	view = demo_view(workbench, b);

demo_view_get_rect(view, &rect);
	rect.x1 += 5;
	rect.x2 -= 5;
	rect.y1 += 5;
	rect.y2 = rect.y1 + 20;

label = rtgui_label_create("Red Left");
	RTGUI_WIDGET_TEXTALIGN(RTGUI_WIDGET(label)) = RTGUI_ALIGN_LEFT;	
	RTGUI_WIDGET_FOREGROUND(RTGUI_WIDGET(label)) = red;		
	rtgui_widget_set_rect(RTGUI_WIDGET(label), &rect);	
	rtgui_container_add_child(RTGUI_CONTAINER(view), RTGUI_WIDGET(label));
	
	 rt_free(b);
     b=RT_NULL;

return view;
}
```
![test.jpg](/uploads/2209_195c1110d1c04878e5a22b8fefeaa0d0.jpg)