iOS十六进制和字符串的相互转换

    NSString *dictString = [dict JSONFragment];//组合成的。 

用这个就行了。。。

    dictString==={"content":"Sadgfdfg","phoneno":"","email":"1049055935@qq.com"}=== 
     
    // 十六进制转换为普通字符串的。 
    + (NSString *)stringFromHexString:(NSString *)hexString { // 
     
    char *myBuffer = (char *)malloc((int)[hexString length] / 2 + 1); 
    bzero(myBuffer, [hexString length] / 2 + 1); 
    for (int i = 0; i < [hexString length] - 1; i += 2) { 
    unsigned int anInt; 
    NSString * hexCharStr = [hexString substringWithRange:NSMakeRange(i, 2)]; 
    NSScanner * scanner = [[[NSScanner alloc] initWithString:hexCharStr] autorelease]; 
    [scanner scanHexInt:&anInt]; 
    myBuffer[i / 2] = (char)anInt; 
    } 
    NSString *unicodeString = [NSString stringWithCString:myBuffer encoding:4]; 
    NSLog(@"------字符串=======%@",unicodeString); 
    return unicodeString; 
     
     
    } 
     
    //普通字符串转换为十六进制的。 
     
    + (NSString *)hexStringFromString:(NSString *)string{ 
    NSData *myD = [string dataUsingEncoding:NSUTF8StringEncoding]; 
    Byte *bytes = (Byte *)[myD bytes]; 
    //下面是Byte 转换为16进制。 
    NSString *hexStr=@""; 
    for(int i=0;i<[myD length];i++) 
     
    { 
    NSString *newHexStr = [NSString stringWithFormat:@"%x",bytes[i]&0xff];///16进制数 
     
    if([newHexStr length]==1) 
     
    hexStr = [NSString stringWithFormat:@"%@0%@",hexStr,newHexStr]; 
     
    else 
     
    hexStr = [NSString stringWithFormat:@"%@%@",hexStr,newHexStr]; 
    } 
    return hexStr; 
    }