二维码扫描ios开发

导入#import <AVFoundation/AVFoundation.h>  

遵守AVCaptureMetadataOutputObjectsDelegate代理

定义属性：
@property (strong,nonatomic)AVCaptureDevice
* device;

@property (strong,nonatomic)AVCaptureDeviceInput * input;

@property (strong,nonatomic)AVCaptureMetadataOutput * output;

@property (strong,nonatomic)AVCaptureSession * session;

@property (strong,nonatomic)AVCaptureVideoPreviewLayer
* preview;

//懒加载device。默认调用后置摄像头

-(AVCaptureDevice *)device{

    NSArray *Devices = [AVCaptureDevicedevicesWithMediaType:AVMediaTypeVideo];

    for (AVCaptureDevice *Devicein Devices)

    {

        //设置为前置摄像头，也可为后置

        if ([Deviceposition] ==
AVCaptureDevicePositionFront )

        {

            return Device;

        }

    }

    return
nil;

}

ViewDidLoad中设置相机：

     // Input

    _input = [AVCaptureDeviceInputdeviceInputWithDevice:self.deviceerror:nil];

    

    // Output

    _output = [[AVCaptureMetadataOutputalloc]init];

    [_outputsetMetadataObjectsDelegate:selfqueue:dispatch_get_main_queue()];

    

    // Session

    _session = [[AVCaptureSessionalloc]init];

    [_sessionsetSessionPreset:AVCaptureSessionPresetHigh];

    if ([_sessioncanAddInput:self.input])

    {

        [_session
addInput:self.input];

    }

    

    if ([_sessioncanAddOutput:self.output])

    {

        [_session
addOutput:self.output];

    }

    

    //
条码类型 AVMetadataObjectTypeQRCode

    // iOS8
下需要使用新的 API

    NSMutableArray *array = [[NSMutableArrayalloc]
initWithObjects:AVMetadataObjectTypeQRCode,AVMetadataObjectTypeUPCECode,
AVMetadataObjectTypeCode39Code,AVMetadataObjectTypeCode39Mod43Code,
AVMetadataObjectTypeEAN13Code,AVMetadataObjectTypeEAN8Code,
AVMetadataObjectTypeCode93Code,AVMetadataObjectTypeCode128Code,
AVMetadataObjectTypePDF417Code,AVMetadataObjectTypeAztecCode,
nil];

    if ([[[UIDevicecurrentDevice]
systemVersion]floatValue] >=
8.0){

        [array addObject:AVMetadataObjectTypeInterleaved2of5Code];

        [array addObject:AVMetadataObjectTypeITF14Code];

        [array addObject:AVMetadataObjectTypeDataMatrixCode];

    }

    //必须加上判断系统是否支持，否则会出错

       

if ([self.output.availableMetadataObjectTypescontainsObject:array])
{

    _output.metadataObjectTypes = array;

    

         }

    

    

    // Preview

    _preview =[AVCaptureVideoPreviewLayerlayerWithSession:self.session];

    _preview.videoGravity =AVLayerVideoGravityResizeAspectFill;

    _preview.frame =CGRectMake(0,0,
[UIScreenmainScreen].bounds.size.width , [UIScreenmainScreen].bounds.size.height);///
220 *220

    //_preview.frame = CGRectMake([UIScreen mainScreen].bounds.size.width/2-110, [UIScreen mainScreen].bounds.size.height/2-110, 220, 220);

    [self.view.layerinsertSublayer:self.previewatIndex:0];

    

    // Start

    [_sessionstartRunning];

#pragma mark AVCaptureMetadataOutputObjectsDelegate

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection
*)connection

{

    NSString *stringValue =
@"";

    

    if ([metadataObjects
count] > 0)

    {

        AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjectsobjectAtIndex:0];

        stringValue = metadataObject.stringValue;

    }

    

    // 发起网络请求

    

//    if (![NSString MyStringIsNULL:stringValue]) {

//        [_session stopRunning];

//        [self netWithStr:stringValue];

//    }

}