编码和解码及MD5加密

常在一些网站源码中看到&#x开头的内容，这是转化成unicode编码后的汉字。

--------------------------------------------unicode编码后的汉字(呵呵)转化成中文(呵呵)---------------------------------------

step1：unicode解码(呵呵 ---------------- \u5475\u5475)

+(NSString *)change:(NSString *)str
{
    NSString *changeStr = @"";
    if (!str||[str isEqualToString:@""]) {
        return @"";
    }
    changeStr = [str stringByReplacingOccurrencesOfString:@"&#x" withString:@"\\u"];
    changeStr = [changeStr stringByReplacingOccurrencesOfString:@";" withString:@""];
    return changeStr;
}

step2：unicode转UTF-8(\u5475\u5475  ---------------- 呵呵)

+(NSString *) unicodeToUtf8:(NSString *)string
{

    NSString *tempStr1 = [string stringByReplacingOccurrencesOfString:@"\\u" withString:@"\\U"];

    NSString *tempStr2 = [tempStr1 stringByReplacingOccurrencesOfString:@"\"" withString:@"\\\""];

    NSString *tempStr3 = [[@"\"" stringByAppendingString:tempStr2] stringByAppendingString:@"\""];

    NSData *tempData = [tempStr3 dataUsingEncoding:NSUTF8StringEncoding];

    NSString* returnStr = [NSPropertyListSerialization propertyListFromData:tempData

                                                           mutabilityOption:NSPropertyListImmutable

                                                                     format:NULL

                                                           errorDescription:NULL];

    return [returnStr stringByReplacingOccurrencesOfString:@"\\r\\n" withString:@"\n"];
}

------------------------------------------------------------UrlEncode--------------------------------------------------

对UTF-8中文UrlEncode编码（呵呵------------------------%e5%91%b5%e5%91%b5）

- (NSString *)URLEncodedString
{
    NSString *encodedString = (NSString *)
    CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                            (CFStringRef)self,
                                            (CFStringRef)@"!$&‘()*+,-./:;[email protected]_~%#[]",
                                            NULL,
                                            kCFStringEncodingUTF8);
    return encodedString;
}

- (NSString*)URLDecodedString
{
    NSString *result = ( NSString *)
    CFBridgingRelease(CFURLCreateStringByReplacingPercentEscapesUsingEncoding(kCFAllocatorDefault,
                                                                              (CFStringRef)self,
                                                                              CFSTR(""),
                                                                              kCFStringEncodingUTF8));
    return result;
}

对gb2312中文UrlEncode编码（呵呵-----------------------%ba%c7%ba%c7）

MD5加密

#import "CommonCrypto/CommonDigest.h"
@implementation MD5
+(NSString *) md5: (NSString *) inPutText
{
    const char *cStr = [inPutText UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(cStr, 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]
             ] lowercaseString];
}
+(NSString *) MD5: (NSString *) inPutText
{
    const char *cStr = [inPutText UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(cStr, 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]
             ] uppercaseString];
}

.

编码和解码及MD5加密