1 NSString 전환 char*

1. UTF8String

const char *cString = [string UTF8String];

2. cStringUsingEncoding:

const char *cString = [string cStringUsingEncoding:NSUTF8StringEncoding];

3. getCString:maxLength:encoding:

char cStringPtr[string.length * 3 + 1];
memset(cStringPtr, 0, sizeof(cStringPtr));
[string getCString:cStringPtr maxLength:sizeof(cStringPtr) encoding:NSUTF8StringEncoding];

UTF8 인코딩은 3 바이트를 차지해야 하기 때문에 여기에 필요합니다*3 . - (BOOL)getCString:(char *)buffer maxLength:(NSUInteger)maxBufferCount encoding:(NSStringEncoding)encoding; //NO return if conversion not possible due to encoding errors or too small of a buffer. The buffer should include room for maxBufferCount bytes; this number should accomodate the expected size of the return value plus the NULL termination character, which this method adds. (So note that the maxLength passed to this method is one more than the one you would have passed to the deprecated getCString:maxLength:.) Use only with 8-bit encodings, and not encodings such as UTF-16 or UTF-32.
버퍼가 너무 작으면 변환 오류가 발생합니다

2char*에서 NSString으로 전환

1. initWithUTF8String:

NSString *string = [[NSString alloc] initWithUTF8String:cString];

2. initWithCString:encoding:

NSString *string = [[NSString alloc] initWithCString:cString encoding:NSUTF8StringEncoding];