iOS Md5编码

第一种方法

+ (NSString *) md5:(NSString *)str{ const char *cStr = [str UTF8String]; unsigned char digest[CC_MD5_DIGEST_LENGTH]; CC_MD5( cStr, (unsigned int)strlen(cStr), digest ); NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2]; for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) [output appendFormat:@"%02X", digest[i]]; return [output lowercaseString];}[/code]第二方法

- (NSString *)cachedFileNameForKey:(NSString *)key { const char *str = [key UTF8String]; if (str == NULL) { str = ""; } unsigned char r[CC_MD5_DIGEST_LENGTH]; CC_MD5(str, (CC_LONG)strlen(str), r); NSString *filename = [NSString stringWithFormat:@"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%@", r[0], r[1], r[2], r[3], r[4], r[5], r[6], r[7], r[8], r[9], r[10], r[11], r[12], r[13], r[14], r[15], [[key pathExtension] isEqualToString:@""] ? @"" : [NSString stringWithFormat:@".%@", [key pathExtension]]];return filename;}[/code]