功能类：二维码扫描（相机扫描，相册扫描）

#import <UIKit/UIKit.h>

@interface SaoMiaoViewController : UIViewController

@end

#import "SaoMiaoViewController.h"
#import <AVFoundation/AVFoundation.h>
#define IS_VAILABLE_IOS8  ([[[UIDevice currentDevice] systemVersion] intValue] >= 8)

@interface SaoMiaoViewController ()<AVCaptureMetadataOutputObjectsDelegate,UINavigationControllerDelegate, UIImagePickerControllerDelegate>
@property (strong, nonatomic) AVCaptureSession *captureSession;

typedef void (^XMSweepBlock)(NSString *result);
@property(nonatomic,copy)XMSweepBlock didRecoiveBlock;
-(void)setDidRecoiveBlock:(XMSweepBlock)didRecoiveBlock;
@end

@implementation SaoMiaoViewController
- (void)viewDidLoad {
[super viewDidLoad];

//    UIButton *btn = [[UIButton alloc]initWithFrame:CGRectMake(0, 0, 15, 20)];
//    [btn setTitle:@"相册" forState: UIControlStateNormal];
//    [btn addTarget:self action:@selector(clickToXiangCe:) forControlEvents:UIControlEventTouchUpOutside];
//    UIBarButtonItem *rightItem = [[UIBarButtonItem alloc]initWithCustomView:btn];
//    self.navigationItem.rightBarButtonItem = rightItem;

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error;
AVCaptureDeviceInput *deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (error) {
NSLog(@"启动镜头失败");
return;
};

if ([self.captureSession canAddInput:deviceInput]) {
[self.captureSession addInput:deviceInput];
}

AVCaptureMetadataOutput *metadataOutput = [[AVCaptureMetadataOutput alloc]init];
if ([self.captureSession canAddOutput:metadataOutput]) {
[self.captureSession addOutput:metadataOutput];
}

[metadataOutput setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

//    NSArray *type = metadataOutput.availableMetadataObjectTypes;
//    NSLog(@"%@",type);

metadataOutput.metadataObjectTypes = @[AVMetadataObjectTypeQRCode,AVMetadataObjectTypeEAN13Code,AVMetadataObjectTypeEAN8Code,AVMetadataObjectTypeCode128Code,AVMetadataObjectTypeCode128Code];

AVCaptureVideoPreviewLayer *layer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
[self.view.layer addSublayer:layer];
layer.frame = self.view.bounds;
// 解析范围, (输出), 有效的扫描范围
CGFloat wh = 300;   // 有效范围 300 * 300, 居中
// 参数值是 0.0 ~ 1.0, Rect:(y,x,height,width)
CGFloat width = wh / self.view.bounds.size.width;
CGFloat height = wh / self.view.bounds.size.height;
CGFloat x = (self.view.bounds.size.width - wh) * 0.5 / self.view.bounds.size.width;
CGFloat y = (self.view.bounds.size.height - wh) * 0.5 / self.view.bounds.size.height;
// Rect:(y,x,height,width)
metadataOutput.rectOfInterest = CGRectMake(y, x, height, width);

[self.captureSession startRunning];

[self addOtherLay:CGRectMake((self.view.bounds.size.width - wh) * 0.5, (self.view.bounds.size.height - wh) * 0.5, wh, wh)];

}
- (IBAction)clicktoxiangce:(id)sender {
UIImagePickerController *picker = [[UIImagePickerController alloc]init];
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
picker.delegate = self;
picker.allowsEditing = YES;
[self presentViewController:picker animated:YES completion:nil];
}
//选中单张照片
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info {
[picker dismissViewControllerAnimated:YES completion:nil];
__block UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
if (!image) {
image = [info objectForKey:UIImagePickerControllerOriginalImage];
}

//系统自带的识别方法
CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:@{ CIDetectorAccuracy : CIDetectorAccuracyHigh }];
CGImageRef ref = (CGImageRef)image.CGImage;
CIImage *cii = [CIImage imageWithCGImage:ref];
NSArray *feacture = [detector featuresInImage:cii];
if (feacture.count >= 1) {
CIQRCodeFeature *feature = [feacture objectAtIndex:0];
NSString *scanResult = feature.messageString;
if (_didRecoiveBlock) {
self.didRecoiveBlock(scanResult);

//            [self selfRemoveFromSuperview];
} else {

[self.captureSession stopRunning];
NSURL *url = [NSURL URLWithString:scanResult];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
UIWebView *webView = [[UIWebView alloc]initWithFrame:self.view.frame];
[self.view addSubview:webView];
[webView loadRequest:request];

}
}
}

#pragma mark - AVCaptureMetadataOutputObjectsDelegate
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection {
AVMetadataMachineReadableCodeObject *metadataObject = metadataObjects.lastObject;
NSString *resultStr = metadataObject.stringValue;
NSLog(@"%@",resultStr);
[self.captureSession stopRunning];
NSURL *url = [NSURL URLWithString:resultStr];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
UIWebView *webView = [[UIWebView alloc]initWithFrame:self.view.frame];
[self.view addSubview:webView];
[webView loadRequest:request];
}

- (void)addOtherLay:(CGRect)rect
{
// Rect为保留的矩形frame值
CGFloat screenWidth = [UIScreen mainScreen].bounds.size.width;
CGFloat screenHeight = [UIScreen mainScreen].bounds.size.height;
CGFloat leftWidth = (screenWidth - rect.size.width) / 2;

CAShapeLayer* layerTop   = [[CAShapeLayer alloc] init];
layerTop.fillColor       = [UIColor blackColor].CGColor;
layerTop.opacity         = 0.5;
layerTop.path            = [UIBezierPath bezierPathWithRect:CGRectMake(0, 0, screenWidth, rect.origin.y)].CGPath;
[self.view.layer addSublayer:layerTop];

CAShapeLayer* layerLeft   = [[CAShapeLayer alloc] init];
layerLeft.fillColor       = [UIColor blackColor].CGColor;
layerLeft.opacity         = 0.5;
layerLeft.path            = [UIBezierPath bezierPathWithRect:CGRectMake(0, rect.origin.y, leftWidth, rect.size.height)].CGPath;
[self.view.layer addSublayer:layerLeft];

CAShapeLayer* layerRight   = [[CAShapeLayer alloc] init];
layerRight.fillColor       = [UIColor blackColor].CGColor;
layerRight.opacity         = 0.5;
layerRight.path            = [UIBezierPath bezierPathWithRect:CGRectMake(screenWidth - leftWidth, rect.origin.y, rect.size.width, rect.size.height)].CGPath;
[self.view.layer addSublayer:layerRight];

CAShapeLayer* layerBottom   = [[CAShapeLayer alloc] init];
layerBottom.fillColor       = [UIColor blackColor].CGColor;
layerBottom.opacity         = 0.5;
layerBottom.path            = [UIBezierPath bezierPathWithRect:CGRectMake(0, CGRectGetMaxY(rect), screenWidth, screenHeight - CGRectGetMaxY(rect))].CGPath;
[self.view.layer addSublayer:layerBottom];
}

- (AVCaptureSession *)captureSession {
if (_captureSession == nil) {
_captureSession = [[AVCaptureSession alloc]init];
}
return _captureSession;
}

@end