iOS编码：MD5(大小写互转)、URL、base64(加密、解

一些工具方法，你可以写成Category，也可以直接复制过去当类方法，不用苦苦的去搜索了

/**
 *  url编码,
 *
 *  @param url 传入要编码的url
 *
 *  @return 返回编码后的字符串
 */
+ (NSString *)encodingUrl:(NSString *)url
{
    NSString * encodedString = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)url, NULL, (CFStringRef)@"!*’();:@&=+$,/?%#[]", kCFStringEncodingUTF8));
    
    return encodedString;
}


/**
 *  url解码
 *
 *  @param url 传入要解码的url
 *
 *  @return 返回解码后的url
 */
+ (NSString *)decodingUrl:(NSString *)url
{
    NSString *encodedString = url;
    NSString *decodedString  = (__bridge_transfer NSString *)CFURLCreateStringByReplacingPercentEscapesUsingEncoding(NULL,
                                                                                                                     (__bridge CFStringRef)encodedString,
                                                                                                                     CFSTR(""),
                                                                                                                     CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));
    return decodedString;
}

/**
 *  MD5加密, 32位 小写
 *
 *  @param str 传入要加密的字符串
 *
 *  @return 返回加密后的字符串
 */
+ (NSString *)MD5:(NSString *)str{
    
    const char *cStr = [str UTF8String];
    
    unsigned char result[16];
    
    CC_MD5( cStr, (int)strlen(cStr), result );
    
    
    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]];
}

/**
 *  MD5加密, 32位 小写
 *
 *  @param str 传入要加密的字符串
 *
 *  @return 返回加密后的字符串
 */

#pragma mark - 32位 小写
+(NSString *)MD5ForLower32Bate:(NSString *)str{
    
    //要进行UTF8的转码
    const char* input = [str UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(input, (CC_LONG)strlen(input), result);
    
    NSMutableString *digest = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
    for (NSInteger i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
        [digest appendFormat:@"%02x", result[i]];
    }
    
    return digest;
}

#pragma mark - 32位 大写
+(NSString *)MD5ForUpper32Bate:(NSString *)str{
    
    //要进行UTF8的转码
    const char* input = [str UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(input, (CC_LONG)strlen(input), result);
    
    NSMutableString *digest = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
    for (NSInteger i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
        [digest appendFormat:@"%02X", result[i]];
    }
    
    return digest;
}

#pragma mark - 16位 大写
+(NSString *)MD5ForUpper16Bate:(NSString *)str{
    
    NSString *md5Str = [self MD5ForUpper32Bate:str];
    
    NSString  *string;
    for (int i=0; i<24; i++) {
        string=[md5Str substringWithRange:NSMakeRange(8, 16)];
    }
    return string;
}


#pragma mark - 16位 小写
+(NSString *)MD5ForLower16Bate:(NSString *)str{
    
    NSString *md5Str = [self MD5ForLower32Bate:str];
    
    NSString  *string;
    for (int i=0; i<24; i++) {
        string=[md5Str substringWithRange:NSMakeRange(8, 16)];
    }
    return string;
}

// 64base字符串转图片
+ (UIImage *)stringToImage:(NSString *)str {
    
    NSData * imageData =[[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];
    
    UIImage *photo = [UIImage imageWithData:imageData ];
    
    return photo;
}

// 图片转64base字符串
+ (NSString *)imageToString:(UIImage *)image {
    
    NSData *imagedata = UIImagePNGRepresentation(image);
    
    NSString *image64 = [imagedata base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
    
    return image64;
}

/**
 base64加密
 */
+(N
+ (NSString *)base64Encoding:(NSString *)str {
    if (!str) {
        //如果sourceData则返回nil，不进行加密。
        return nil;
    }
    
    NSData *sourceData = [str dataUsingEncoding:NSUTF8StringEncoding];
    
    NSString *resultString = [sourceData base64EncodedStringWithOptions:
                              NSDataBase64Encoding64CharacterLineLength];
    return resultString;
}

+ (NSString *)decodingBase64:(NSString *)sourceString{
    if (!sourceString) {
        return nil;//如果sourceString则返回nil，不进行解密。
    }
    NSData *resultData = [[NSData alloc]initWithBase64EncodedString:sourceString options:NSDataBase64DecodingIgnoreUnknownCharacters];
    
    return [[NSString alloc] initWithData:resultData encoding:NSUTF8StringEncoding];
}