关于扫描POS二维码遇到的问题

stringValue = POS90711012511000125110003000053000011000000000002000000000000000016224161398260MERCH¸£¿¨ÊÖ»ú
2016-08-15 10:00:38.891 YuFu_Wallet[1914:1168136] -[QRViewController comperterStr:] [Line 79] POS
907110125110001
25110003
000053
000011
000000000002
0000
000000000000
1
622416139826
0
stringValue 就是截取出来的商户名称，里面有奇异字符，需要转成 中文；

折腾了2天，
modelPos.merName = [self
JapaneseToString:stringValue];

-(NSString *)JapaneseToString:(NSString *)string{
#if 0
NSStringEncoding dec = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingMacJapanese);

NSData *data=[string dataUsingEncoding:dec];

NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);

NSString *retStr = [[NSString alloc] initWithData:data encoding:enc];

DLog(@"retStr before = %@",retStr);
if (MBIsStringWithAnyText(retStr))//如果扫描中文乱码则需要处理，否则不处理
{
DLog(@"不为空");
// NSInteger max = [string length];
// char *nbytes = malloc(max + 1);
// for (int i = 0; i < max; i++)
// {
// unichar ch = [string characterAtIndex: i];
// nbytes[i] = (char) ch;
// }
// nbytes[max] = '\0';
// retStr =[NSString stringWithCString: nbytes
// encoding: enc];
}else{
DLog(@"为空");
retStr = [self gb_2312ToUTF_8WithString:string] ;
}

return retStr;
#endif
}

//多种格式支持

NSString *retStr;

// 1，utf8编码的
NSStringEncoding dec =
CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingMacJapanese);

//根据字节来判断返回来的编码格式
const
char * sc = [string cStringUsingEncoding:dec];

if (sc ==
NULL) {//正常编码
if (MBIsStringWithAnyText(retStr))//如果扫描中文乱码则需要处理，否则不处理
{
retStr=string;
}else{
DLog(@"为空");
retStr = [self
gb_2312ToUTF_8WithString:string] ;
}

- (NSString *)gb_2312ToUTF_8WithString:(NSString *)string
{
NSStringEncoding enc =
CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);

NSData *data=[string
dataUsingEncoding:enc];

NSString *retStr = [[NSString
alloc] initWithData:data
encoding:enc];
DLog(@"retStr = %@",retStr);

if (retStr)//如果扫描中文乱码则需要处理，否则不处理
{
DLog(@"不为空");
NSInteger max = [string
length];
char *nbytes =
malloc(max + 1);
for (int i =
0; i < max; i++)
{
unichar ch = [string
characterAtIndex: i];
nbytes[i] = (char) ch;
}
nbytes[max] = '\0';
retStr =[NSString
stringWithCString: nbytes
encoding: enc];
}else{
DLog(@"为空");
// retStr = [[NSString alloc]initWithData:[self dataByHealingGB18030Stream:data] encoding:enc];
}

return retStr;
}

}else
if (IsTextUTF8(sc,
strlen(sc))) {

NSData *data=[string
dataUsingEncoding:dec];

retStr = [[NSString
alloc] initWithData:data
encoding:NSUTF8StringEncoding];

}else{

NSData *data=[string
dataUsingEncoding:dec];
//
NSStringEncoding enc =
CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);

retStr = [[NSString
alloc] initWithData:data
encoding:enc];

}

//找的一些c的方法 来判断返回来串的编码格式

int isgbk(const
char *s, size_t ns)
{
if(ns >
2 && (uint8_t)*s >=
0x81 && (uint8_t)*s <=
0xfe
&& (
((uint8_t)*(s+1) >=
0x80 && (uint8_t)*(s+1) <=
0x7e)
|| ((uint8_t)*(s+1) >=
0xa1 && (uint8_t)*(s+1) <=
0xfe)
)
)
{
return
1;
}
return
0;
}

int IsTextUTF8(const
char* str,long length)
{
int i;
int nBytes=0;//UFT8可用1-6个字节编码,ASCII用一个字节
unsigned
char chr;
bool bAllAscii=true;
//如果全部都是ASCII,
说明不是UTF-8
for(i=0;i<length;i++)
{
chr= *(str+i);
if( (chr&0x80) !=
0 ) //
判断是否ASCII编码,如果不是,说明有可能是UTF-8,ASCII用7位编码,但用一个字节存,最高位标记为0,o0xxxxxxx
bAllAscii= false;
if(nBytes==0)
//如果不是ASCII码,应该是多字节符,计算字节数
{
if(chr>=0x80)
{
if(chr>=0xFC&&chr<=0xFD)
nBytes=6;
else
if(chr>=0xF8)
nBytes=5;
else
if(chr>=0xF0)
nBytes=4;
else
if(chr>=0xE0)
nBytes=3;
else
if(chr>=0xC0)
nBytes=2;
else
{
return
false;
}
nBytes--;
}
}
else
//多字节符的非首字节,应为 10xxxxxx
{
if( (chr&0xC0) !=
0x80 )
{
return
false;
}
nBytes--;
}
}

if( nBytes >
0 ) //违返规则
{
return
false;
}

if( bAllAscii )
//如果全部都是ASCII,
说明不是UTF-8
{
return
false;
}
return
true;
}