md5加密导入库报错解决

一，用系统自带的MD5进行加密方法一：- (NSString *)md5HexDigest:(NSString*)input{ const char* str = [input UTF8String]; unsigned char result[CC_MD5_DIGEST_LENGTH]; CC_MD5(str, strlen(str), result); NSMutableString *ret = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH*2]; for(int i = 0; i<CC_MD5_DIGEST_LENGTH; i++) { [ret appendFormat:@"%02x",result]; } return ret;}方法二：
- (NSString *)md5:(NSString *)str
{
const char *cStr = [str UTF8String];
unsigned char result[16];
CC_MD5(cStr, strlen(cStr), result); // This is the md5 call
return [NSString stringWithFormat:
@"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
result[0], result[1], result[2], result[3],
result[4], result[5], result[6], result[7],
result[8], result[9], result[10], result[11],
result[12], result[13], result[14], result[15]
];
}

二，导入系统类库：
#import <CommonCrypto/CommonDigest.h>

三，报错：ld: cannot link directly with /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.1.sdk/usr/lib/system/libcommonCrypto.dylib. Link against the umbrella framework 'System.framework' instead.

四，解决方案：
删去libcommonCrypto.dylib，用System.framework库中的libSystem.dylib替代。

MD5加密和导入库的解决方案分别来自不同出处的网络资源总结，如有侵权，请联系本博主注明。