iOS获取字符串string的异或值

1、HKXORManager.h文件

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface HKXORManager : NSObject

+ (HKXORManager *)shareManager;
/**
 * 计算异或值
 * @param string 需要异或的字符串
 * @return 获取异或后的字符串
 */
- (NSString *)stringXOR:(NSString *)string;

@end

NS_ASSUME_NONNULL_END

　　

2、HKXORManager.m文件

#import "HKXORManager.h"

@implementation HKXORManager

+ (HKXORManager *)shareManager {
    static HKXORManager *instance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        instance = [[HKXORManager alloc] init];
    });
    return instance;
}

- (NSString *)stringXOR:(NSString *)string {
    if (string.length%2) {
        string = [NSString stringWithFormat:@"0%@", string];
    }
    NSString *code = @"00";
    for (int i=0; i<string.length; i=i+2) {
        // 两位两位取出
        NSString *subString = [string substringWithRange:NSMakeRange(i, 2)];
        // subString转为16进制
        NSString *hexString = [self toHex:[subString integerValue]];
        code = [self pinxCreator:code withPinv:hexString];
    }
    return code;
}

- (NSString *)pinxCreator:(NSString *)pan withPinv:(NSString *)pinv {
    if (pan.length != pinv.length) {
        return nil;
    }
    const char *panchar = [pan UTF8String];
    const char *pinvchar = [pinv UTF8String];
    NSString *temp = [[NSString alloc] init];
    for (int i = 0; i < pan.length; i++) {
        int panValue = [self charToint:panchar[i]];
        int pinvValue = [self charToint:pinvchar[i]];
        temp = [temp stringByAppendingString:[NSString stringWithFormat:@"%X",panValue^pinvValue]];
    }
    return temp;
}

- (int)charToint:(char)tempChar {
    if (tempChar >= '0' && tempChar <='9') {
        return tempChar - '0';
    } else if (tempChar >= 'A' && tempChar <= 'F') {
        return tempChar - 'A' + 10;
    } else if (tempChar >= 'a' && tempChar <= 'f') {
        return tempChar - 'a' + 10;
    }
    return 0; 
} 

// 十进制转换为十六进制的。

- (NSString *)toHex:(long long int)tmpid {

    NSString *nLetterValue;

    NSString *str =@"";

    long long int ttmpig;

    for (int i = 0; i<9; i++) {

        ttmpig = tmpid%16;

        tmpid  = tmpid/16;

        switch (ttmpig) {

            case 10:

                nLetterValue =@"A";

                break;

            case 11:

                nLetterValue =@"B";

                break;

            case 12:

                nLetterValue =@"C";

                break;

            case 13:

                nLetterValue =@"D";

                break;

            case 14: nLetterValue =@"E";

                break; case 15:

                nLetterValue =@"F";

                break;

            default:

                nLetterValue=[[NSString alloc]initWithFormat:@"%lli",ttmpig];

        }

        str = [nLetterValue stringByAppendingString:str];

        if (tmpid == 0) { break; }

    }

    if (str.length==1) {

        str = [NSString stringWithFormat:@"0%@", str];

    }

    return str;

}

@end