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;        }    }        }

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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];    }