ios 将 HEX NSString 转换为 NSData
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Converting HEX NSString To NSData
提问by Pranav Jaiswal
I'm trying to convert a Hex NSStringto NSData(I'm using the below attached code). The following is the output:
我正在尝试将十六进制转换NSString为NSData（我正在使用下面的附加代码）。以下是输出：
<00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000>
which looks totally irrelevant to me. Any idea/ suggestions on where its going wrong?
这看起来与我完全无关。关于哪里出错的任何想法/建议？
NSString *strData = @"72ff63cea198b3edba8f7e0c23acc345050187a0cde5a9872cbab091ab73e553";
NSLog(@"string Data length is %d",[strData length]);
NSMutableData *commandToSend= [[NSMutableData alloc] init];
unsigned char whole_byte;
char byte_chars[2];
int i;
for (i=0; i < [strData length]/2; i++) {
byte_chars[0] = [strData characterAtIndex:i*2];
byte_chars[1] = [strData characterAtIndex:i*2+1];
whole_byte = strtol(byte_chars, NULL, [strData length]);
[commandToSend appendBytes:&whole_byte length:1];
}
NSLog(@"%@", commandToSend);
回答by Nikunj Jadav
NSString *command = @"72ff63cea198b3edba8f7e0c23acc345050187a0cde5a9872cbab091ab73e553";
command = [command stringByReplacingOccurrencesOfString:@" " withString:@""];
NSMutableData *commandToSend= [[NSMutableData alloc] init];
unsigned char whole_byte;
char byte_chars[3] = {'<9dc69faf a7434ba9 aef57f5c 365d571f 4c3753c4 ae13db42 57d184ca e00246c5>
','+ (NSData *)dataFromHexString:(NSString *)string
{
string = [string lowercaseString];
NSMutableData *data= [NSMutableData new];
unsigned char whole_byte;
char byte_chars[3] = {'@implementation NSData (HexString)
// Not efficent
+(id)dataWithHexString:(NSString *)hex
{
char buf[3];
buf[2] = '+ (NSData *)dataFromHexString:(NSString *) string {
if([string length] % 2 == 1){
string = [@"0"stringByAppendingString:string];
}
const char *chars = [string UTF8String];
int i = 0, len = (int)[string length];
NSMutableData *data = [NSMutableData dataWithCapacity:len / 2];
char byteChars[3] = {'##代码##','##代码##','##代码##'};
unsigned long wholeByte;
while (i < len) {
byteChars[0] = chars[i++];
byteChars[1] = chars[i++];
wholeByte = strtoul(byteChars, NULL, 16);
[data appendBytes:&wholeByte length:1];
}
return data;
}
';
NSAssert(0 == [hex length] % 2, @"Hex strings should have an even number of digits (%@)", hex);
unsigned char *bytes = malloc([hex length]/2);
unsigned char *bp = bytes;
for (CFIndex i = 0; i < [hex length]; i += 2) {
buf[0] = [hex characterAtIndex:i];
buf[1] = [hex characterAtIndex:i+1];
char *b2 = NULL;
*bp++ = strtol(buf, &b2, 16);
NSAssert(b2 == buf + 2, @"String should be all hex digits: %@ (bad digit around %d)", hex, i);
}
return [NSData dataWithBytesNoCopy:bytes length:[hex length]/2 freeWhenDone:YES];
}
@end
','##代码##','##代码##'};
int i = 0;
int length = string.length;
while (i < length-1) {
char c = [string characterAtIndex:i++];
if (c < '0' || (c > '9' && c < 'a') || c > 'f')
continue;
byte_chars[0] = c;
byte_chars[1] = [string characterAtIndex:i++];
whole_byte = strtol(byte_chars, NULL, 16);
[data appendBytes:&whole_byte length:1];
}
return data;
}
','##代码##'};
int i;
for (i=0; i < [command length]/2; i++) {
byte_chars[0] = [command characterAtIndex:i*2];
byte_chars[1] = [command characterAtIndex:i*2+1];
whole_byte = strtol(byte_chars, NULL, 16);
[commandToSend appendBytes:&whole_byte length:1];
}
NSLog(@"%@", commandToSend);
回答by zaph
Here is another method that also handles leading <, trailing >and embedded spaces such as
这是另一种处理前导<、尾随>和嵌入空格的方法，例如
Code:
代码：
##代码##This is based on the answer by @Nikunj R. Jadav
这是基于@Nikunj R. Jadav 的回答
回答by Shwet Solanki
This might be more useful, Apple has shared a NSData category.
这可能更有用，Apple 共享了一个 NSData 类别。
The code is:
代码是：
##代码##回答by jefry Hymany
I see several solution have been post only able to convert string with even length.
我看到有几个解决方案只能转换长度为偶数的字符串。
So here is my solution which also able return correct data if the string is odd length like this "DBA" became data like this this "\x0D\xBA"
所以这是我的解决方案，如果字符串是奇数长度，像这样“ DBA”变成这样的数据“\x0D\xBA”，它也可以返回正确的数据
##代码##