ios7新增api实现扫描二维码

本来用的ZBar开源库实现的扫描二维码，但是貌似不支持arm64了，也没有在更新。

现在不用适配ios7以下，而iOS新增系统API已支持扫码，参考老外的一篇博客做了个demo，需要的可以参考下

参考博客：http://www.appcoda.com/qr-code-ios-programming-tutorial/

#import <AVFoundation/AVFoundation.h>
@interface QRCodeReadController : BaseViewController<AVCaptureMetadataOutputObjectsDelegate>

@property (weak, nonatomic) IBOutlet UIView *viewPreview;
@end

在xib上加一个viewPreview，用来扫码时动态显示获取到的摄像头的内容

@interface QRCodeReadController ()
{
NSInteger maxY;
NSInteger minY;
NSTimer *timer;

UIImageView *line;
}
@property (nonatomic) BOOL isReading;

@property (nonatomic, strong) AVCaptureSession *captureSession;
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *videoPreviewLayer;

-(BOOL)startReading;
-(void)stopReading;

@end

@implementation QRCodeReadController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
_isReading = NO;
if ([self startReading]) {
maxY = 280;
minY = 2;
line =[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 280, 10)];  // 0 -200
[line setImage:[UIImage imageNamed:@"e0"]];
[_viewPreview addSubview:line];

timer = [NSTimer scheduledTimerWithTimeInterval:1.0/40 target:self selector:@selector(move) userInfo:nil repeats:YES];
};

}

/*
*
*
AVCaptureMetadataOutput object. This class in combination with the AVCaptureMetadataOutputObjectsDelegate protocol will manage to intercept any metadata found in the input device (meaning data in a QR code captured by our camera) and translate it to a human readable format.
*/
- (BOOL)startReading {
NSError *error;

AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];

if (!input) {
NSLog(@"%@", [error localizedDescription]);
return NO;
}
_captureSession = [[AVCaptureSession alloc] init];
[_captureSession addInput:input];

AVCaptureMetadataOutput *captureMetadataOutput = [[AVCaptureMetadataOutput alloc] init];
[_captureSession addOutput:captureMetadataOutput];

dispatch_queue_t dispatchQueue;
dispatchQueue = dispatch_queue_create("myQueue", NULL);
[captureMetadataOutput setMetadataObjectsDelegate:self queue:dispatchQueue];
[captureMetadataOutput setMetadataObjectTypes:[NSArray arrayWithObject:AVMetadataObjectTypeQRCode]];

//show to user what the camera of the device sees  using a AVCaptureVideoPreviewLayer
_videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];
[_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
[_videoPreviewLayer setFrame:_viewPreview.layer.bounds];
[_viewPreview.layer addSublayer:_videoPreviewLayer];

[_captureSession startRunning];

return YES;
}

-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{
if (metadataObjects != nil && [metadataObjects count] > 0) {
AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0];
if ([[metadataObj type] isEqualToString:AVMetadataObjectTypeQRCode]) {
[self performSelectorOnMainThread:@selector(stopReading) withObject:nil waitUntilDone:NO];
NSLog(@"metadataObj  string = %@",[metadataObj stringValue]);
_isReading = NO;
}
}
}

-(void)stopReading{
[_captureSession stopRunning];
_captureSession = nil;

[_videoPreviewLayer removeFromSuperlayer];
}

// 扫描时，移动扫描线
-(void)move
{
NSLog(@"+++");
static BOOL flag = TRUE;  // true down  and false up
if (flag) {
if (line.frame.origin.y <maxY) {
line.frame = CGRectMake(
line.frame.origin.x, line.frame.origin.y +5,
line.frame.size.width, line.frame.size.height
);
}else{
flag = !flag;
if (_isReading&&[timer isValid]) {
[timer invalidate];
}
}
}else
{
if (line.frame.origin.y >minY) {
line.frame = CGRectMake(
line.frame.origin.x, line.frame.origin.y -5,
line.frame.size.width, line.frame.size.height
);
}else
{
flag = !flag;
}
}

}

/*****************************************************************************************/

识别图片二维码

现在有从含二维码的图片直接出二维码中信息的需求，查相关资料发现，原生api在iOS8才支持（CIQRCodeFeature

）

见 http://stackoverflow.com/questions/27505420/is-it-possible-to-decode-qrcode-image-to-value

解决方案用的zxing的ZXQRcodeDecoder
http://stackoverflow.com/questions/15575554/zxingobjc-cant-decode-image-taken-from-uiimagepickercontroller

NSString *path = [[NSBundle mainBundle] pathForResource:@"code" ofType:@"png"];
UIImage *image = [UIImage imageWithContentsOfFile:path];

NSError *error = nil;

ZXQRCodeReader *reader = [[ZXQRCodeReader alloc]init];

ZXLuminanceSource *source = [[ZXCGImageLuminanceSource alloc] initWithCGImage:[image CGImage]];
ZXHybridBinarizer *binazer = [ZXHybridBinarizer binarizerWithSource:source];
ZXBinaryBitmap *bitmap = [[ZXBinaryBitmap alloc]initWithBinarizer:binazer];

ZXResult *result = [reader decode:bitmap
hints:nil
error:&error];
if(result){
NSLog(@"%@",result);
[[[UIAlertView alloc] initWithTitle:@"Success" message:result.text
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil, nil] show];
} else {
// Use error to determine why we didn't get a result, such as a barcode
// not being found, an invalid checksum, or a format inconsistency.
[[[UIAlertView alloc] initWithTitle:@"ERROR" message:[error localizedDescription]
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil, nil] show];
}