iOS：card.io使用

最近项目要用到一个功能：通过扫描银行卡，获取银行卡号，在网上搜过后，选用了card.io这个SDK，过程如下：
（1）下载Card.io
Card.io是让手机摄像头获取信用卡的信息，中间利用了OCR（光学字符识别）的扫描技术返回结果，它还推出了SDK（软件开发包），让开发者们可以把card.io添加到自己的应用当中。可以在https://github.com/paypal/PayPal-iOS-SDK下载最新的SDK
（2）添加到项目里
1、将下载的SDK包里名为CardIO的文件拖到工程里，在TARGETS-Build Phases - Link Binary With Librarys添加下面依赖库
* AudioToolbox
* AVFoundation
* CoreGraphics
* CoreMedia
* CoreVideo
* Foundation
* MobileCoreServices
* OpenGLES
* QuartzCore
* Security
* UIKit
如果是xcode5或者更新的版本，只需要添加下面的库
* AVFoundation
* AudioToolbox
* CoreMedia
* MobileCoreServices
并且保证Build Settings里面这两项都是YES：
* Enable Modules (C and Objective-C)
*Link Frameworks Automatically

2、在TARGETS-Build Settings添加 -lc++到Other Linker Flags

（3）使用
我是把它作为一个viewController类使用
代码：
导入

#import "CardIO.h"
#import "CardIOPaymentViewControllerDelegate.h"


- (void)viewWillAppear:(BOOL)animated {
  [super viewWillAppear:animated];
  [CardIOUtilities preload];
}
//开始扫描
- (IBAction)scanCard:(id)sender
 {
  CardIOPaymentViewController *scanViewController = [[CardIOPaymentViewController alloc] initWithPaymentDelegate:self];
  [self presentViewController:scanViewController animated:YES completion:nil];
}
下面是代理方法
//取消扫描
- (void)userDidCancelPaymentViewController:(CardIOPaymentViewController *)scanViewController 
{
  NSLog(@"User canceled payment info");
  // Handle user cancellation here...
  [scanViewController dismissViewControllerAnimated:YES completion:nil];
}
//扫描完成
-(void)userDidProvideCreditCardInfo:(CardIOCreditCardInfo *)info inPaymentViewController:(CardIOPaymentViewController *)scanViewController 
{
  //扫描结果
//CardIOCreditCardInfo *info里面包含了银行卡的一些信息，如info.cardNumber是扫描的银行卡号，现实的是完整号码，而info.redactedCardNumber只显示银行卡后四位，前面的用*代替了，返回的银行卡号都没有空格
可以用下面注释的方法来加空格
//    NSString *strTem = [info.cardNumber stringByReplacingOccurrencesOfString:@" " withString:@""];
//    NSString *strTem2 = @"";
//    if (strTem.length % 4 == 0)
//    {
//        int count = strTem.length / 4;
//        for (int i = 0; i < count; i++)
//        {
//            NSString *str = [strTem substringWithRange:NSMakeRange(i * 4, 4)];
//            strTem2 = [strTem2 stringByAppendingString:[NSString stringWithFormat:@"%@ ", str]];
//        }
//    }
//    else
//    {
//        int count = strTem.length / 4;
//        for (int j = 0; j <= count; j++)
//        {
//            if (j == count)
//            {
//                NSString *str = [strTem substringWithRange:NSMakeRange(j * 4, strTem.length % 4)];
//                strTem2 = [strTem2 stringByAppendingString:[NSString stringWithFormat:@"%@ ", str]];
//            }
//            else
//            {
//                NSString *str = [strTem substringWithRange:NSMakeRange(j * 4, 4)];
//                strTem2 = [strTem2 stringByAppendingString:[NSString stringWithFormat:@"%@ ", str]];
//            }
//        }
//    }
  NSLog(@"Received card info. Number: %@, expiry: %02i/%i, cvv: %@.", info.redactedCardNumber, info.expiryMonth, info.expiryYear, info.cvv);
  // Use the card info...
  [scanViewController dismissViewControllerAnimated:YES completion:nil];
}