iOS 下NSData与16进制串相互转化

16进制字符串转data

-(NSData*)data_With_HexString:(NSString*)hexString

{

// hexString的长度应为偶数

if([hexStringlength] %2!=0)

returnnil;

NSUIntegerlen = [hexStringlength];

NSMutableData*retData = [[NSMutableDataalloc]init];

constchar*ch = [[hexStringdataUsingEncoding:NSASCIIStringEncoding]bytes];

for(inti=0; i

intheight=0;

if(ch[i]>='0'&& ch[i]<='9')

height = ch[i] -'0';

elseif(ch[i]>='A'&& ch[i]<='F')

height = ch[i] -'A'+10;

elseif(ch[i]>='a'&& ch[i]<='f')

height = ch[i] -'a'+10;

else

//错误数据

returnnil;

intlow=0;

if(ch[i+1]>='0'&& ch[i+1]<='9')

low = ch[i+1] -'0';

elseif(ch[i+1]>='A'&& ch[i+1]<='F')

low = ch[i+1] -'A'+10;

elseif(ch[i+1]>='a'&& ch[i+1]<='f')

low = ch[i+1] -'a'+10;

else

//错误数据

returnnil;

intbyteValue = height*16+ low;

[retDataappendBytes:&byteValuelength:1];

}

returnretData;

}

NSdata转16进制串

-(NSString*)convertDataToHexStrBLE:(NSData*)data {

if(!data || [datalength] ==0)

{

returnnil;

}

NSMutableString*string = [[NSMutableStringalloc]initWithCapacity:[datalength]];

[dataenumerateByteRangesUsingBlock:^(constvoid*bytes,NSRangebyteRange,BOOL*stop) {

unsignedchar*dataBytes = (unsignedchar*)bytes;

for(NSIntegeri =0; i < byteRange.length; i++)

{

NSString*hexStr = [NSStringstringWithFormat:@"%x", (dataBytes[i]) &0xff];

if([hexStrlength] ==2) {

[stringappendString:hexStr];

}else

{

[stringappendFormat:@"0%@", hexStr];

}

}

}];

returnstring;

}