@interface ViewController ()<AVCaptureMetadataOutputObjectsDelegate>//用於處理採集資訊的代理
{
    AVCaptureSession * session;//輸入輸出的中間橋樑
}
@end
@implementation ViewController
 
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    //獲取攝像裝置
    AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    //建立輸入流
    AVCaptureDeviceInput * input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
    if (!input) return;
    //建立輸出流
    AVCaptureMetadataOutput * output = [[AVCaptureMetadataOutput alloc]init];
    //設定代理 在主執行緒裡重新整理
    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    //設定有效掃描區域
    CGRect scanCrop=[self getScanCrop:_scanWindow.bounds readerViewBounds:self.view.frame];
     output.rectOfInterest = scanCrop;
    //初始化連結物件
    _session = [[AVCaptureSession alloc]init];
    //高質量採集率
    [_session setSessionPreset:AVCaptureSessionPresetHigh];
    
    [_session addInput:input];
    [_session addOutput:output];
    //設定掃碼支援的編碼格式(如下設定條形碼和二維碼相容)
    
 
[email protected][AVMetadataObjectTypeQRCode,AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code];
    
    AVCaptureVideoPreviewLayer * layer = [AVCaptureVideoPreviewLayer layerWithSession:_session];
    layer.videoGravity=AVLayerVideoGravityResizeAspectFill;
    layer.frame=self.view.layer.bounds;
    [self.view.layer insertSublayer:layer atIndex:0];
    //開始捕獲
    [_session startRunning];
}

-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{
    if (metadataObjects.count>0) {
        //[session stopRunning];
        AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex : 0 ];
        //輸出掃描字串
        NSLog(@"%@",metadataObject.stringValue);
    }
}

#pragma mark-> 獲取掃描區域的比例關係
-(CGRect)getScanCrop:(CGRect)rect readerViewBounds:(CGRect)readerViewBounds
{
    
    CGFloat x,y,width,height;
    
    x = (CGRectGetHeight(readerViewBounds)-CGRectGetHeight(rect))/2/CGRectGetHeight(readerViewBounds);
    y = (CGRectGetWidth(readerViewBounds)-CGRectGetWidth(rect))/2/CGRectGetWidth(readerViewBounds);
    width = CGRectGetHeight(rect)/CGRectGetHeight(readerViewBounds);
    height = CGRectGetWidth(rect)/CGRectGetWidth(readerViewBounds);
    
    return CGRectMake(x, y, width, height);
    
}

#pragma mark-> 我的相簿
-(void)myAlbum{
    
    NSLog(@"我的相簿");
    if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){
        //1.初始化相簿拾取器
        UIImagePickerController *controller = [[UIImagePickerController alloc] init];
        //2.設定代理
        controller.delegate = self;
        //3.設定資源：
        /**
         UIImagePickerControllerSourceTypePhotoLibrary,相簿
         UIImagePickerControllerSourceTypeCamera,相機
         UIImagePickerControllerSourceTypeSavedPhotosAlbum,照片庫
         */
        controller.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
        //4.隨便給他一個轉場動畫
        controller.modalTransitionStyle=UIModalTransitionStyleFlipHorizontal;
        [self presentViewController:controller animated:YES completion:NULL];
        
    }else{
        
        UIAlertView * alert = [[UIAlertView alloc]initWithTitle:@"提示" message:@"裝置不支援訪問相簿，請在設定->隱私->照片中進行設定！" delegate:nil cancelButtonTitle:@"確定" otherButtonTitles:nil, nil];
        [alert show];
    }
    
}

#pragma mark-> imagePickerController delegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    //1.獲取選擇的圖片
    UIImage *image = info[UIImagePickerControllerOriginalImage];
    //2.初始化一個監測器
    CIDetector*detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:@{ CIDetectorAccuracy : CIDetectorAccuracyHigh }];
    
    [picker dismissViewControllerAnimated:YES completion:^{
        //監測到的結果陣列
        NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:image.CGImage]];
        if (features.count >=1) {
            /**結果物件 */
            CIQRCodeFeature *feature = [features objectAtIndex:0];
            NSString *scannedResult = feature.messageString;
            UIAlertView * alertView = [[UIAlertView alloc]initWithTitle:@"掃描結果" message:scannedResult delegate:nil cancelButtonTitle:@"確定" otherButtonTitles:nil, nil];
            [alertView show];
          
        }
        else{
            UIAlertView * alertView = [[UIAlertView alloc]initWithTitle:@"提示" message:@"該圖片沒有包含一個二維碼！" delegate:nil cancelButtonTitle:@"確定" otherButtonTitles:nil, nil];
            [alertView show];
            
        }
        
  
    }];
    
    
}