iOS 生成32位随机字符串

+ (NSString *)getPKey;

+ (NSString *)getPKey{
    
    NSMutableString *timeMutable = [[NSMutableString alloc] init];
    //得到32位随机字符
    for(int i = 0; i < 32; i++)
    {
        NSInteger index = arc4random() % (randomString.length-1);
        
        if (index < randomString.length) {
            [timeMutable appendString:[randomString substringWithRange:NSMakeRange(index, 1)]];
        }else{//防止出现其它问题
            [timeMutable appendString:@"T"];
        }
    }
        
    return timeMutable;
}

 放在工具类里，然后直接调用，即可获取到一个32位的随机字符串