最近项目添加扫描支付宝付款二维码的功能，查看资料ZXing和ZBar，两个是推荐使用的，但是在集成Zbar的时候出现
“Undefined symbols for architecture x86_64:”和“linker command failed with exit code 1 (use -v to see invocation)”的错误，并没有很好的解决，真是因为不兼容64位系统么？......
所以采用的系统的AVFoundation框架实现用能。
话不多说先上效果图

扫描二维码

代码来啦~~~

成员变量

@interface AliScanVC () <AVCaptureMetadataOutputObjectsDelegate>

@property (strong, nonatomic) IBOutlet UIView *contentView;

@property (strong, nonatomic) UIView * boxView;
@property (strong, nonatomic) CALayer * scanLayer;

@property (nonatomic, strong) UILabel * TipLabel;
@property (nonatomic, strong) UIButton * inputBtn;
@property (nonatomic, strong) UITextField * textField;

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

@end

关键代码

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    
    [self startReading];
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    
    [self stopReading];
}

#pragma mark - 二维码
- (BOOL)startReading
{
    // 获取 AVCaptureDevice 实例
    NSError * error;
    
    //1.初始化捕捉设备（AVCaptureDevice），类型为AVMediaTypeVideo
    AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    //2.用captureDevice创建输入流
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
    if (!input) {
        KTLog(@"captureDevice创建输入流--Error:%@", [error localizedDescription]);
        return NO;
    }
    //3.创建媒体数据输出流
    AVCaptureMetadataOutput *captureMetadataOutput = [[AVCaptureMetadataOutput alloc] init];
    
    //4.实例化捕捉会话
    _captureSession = [[AVCaptureSession alloc] init];
    //将输入流添加到会话
    [_captureSession addInput:input];
    //将媒体输出流添加到会话中
    [_captureSession addOutput:captureMetadataOutput];
    
    //5.创建串行队列，并加媒体输出流添加到队列当中
    dispatch_queue_t dispatchQueue;
    dispatchQueue = dispatch_queue_create("myQueue", NULL);
    //设置代理
    [captureMetadataOutput setMetadataObjectsDelegate:self queue:dispatchQueue];
    //设置输出媒体数据类型为QRCode
    [captureMetadataOutput setMetadataObjectTypes:[NSArray arrayWithObject:AVMetadataObjectTypeQRCode]];
    
    //6.实例化预览图层
    _videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];
    
    //7.设置预览图层填充方式
    [_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
    
    //8.设置图层的frame
    [_videoPreviewLayer setFrame:self.contentView.layer.bounds];
    
    //9.将图层添加到预览view的图层上
    [self.contentView.layer addSublayer:_videoPreviewLayer];
    
    //10.设置扫描范围
    captureMetadataOutput.rectOfInterest = CGRectMake(0.2f, 0.2f, 0.8f, 0.8f);
    //扫描框
    CGFloat ScanWIDTH = SCREEN_WIDTH/1.5;
    CGFloat ScanX = (SCREEN_WIDTH - ScanWIDTH)/2;
    CGFloat ScanY = (self.contentView.frame.size.height-ScanWIDTH)/3;
    _boxView = [[UIView alloc] initWithFrame:CGRectMake(ScanX,ScanY,ScanWIDTH,ScanWIDTH)];
    _boxView.layer.borderColor = [UIColor whiteColor].CGColor;
    _boxView.layer.borderWidth = 1.0f;
    [self.contentView addSubview:_boxView];
    
    // 提示
    _TipLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, ScanY+ScanWIDTH+10, SCREEN_WIDTH, 18)];
    _TipLabel.text = @"请扫描客户的支付宝付款码完成收款";
    _TipLabel.textAlignment = NSTextAlignmentCenter;
    _TipLabel.textColor = [UIColor whiteColor];
    _TipLabel.font = [UIFont systemFontOfSize:14];
    [self.contentView addSubview:_TipLabel];
    
    _inputBtn = [UIButton buttonWithType:UIButtonTypeSystem];
    _inputBtn.frame = CGRectMake(ScanX, self.contentView.frame.size.height-44-95, ScanWIDTH, 44);
    [_inputBtn setTitle:@"输入付款码" forState:UIControlStateNormal];
    _inputBtn.titleLabel.font = [UIFont systemFontOfSize:14];
    [_inputBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [_inputBtn setBackgroundImage:[_IMG(@"ALiBtn") imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] forState:UIControlStateNormal];
    [_inputBtn addTarget:self action:@selector(inputAliPayNum) forControlEvents:UIControlEventTouchUpInside];
    [self.contentView addSubview:_inputBtn];
    
    //10.开始扫描
    [_captureSession startRunning];
    
    return YES;
}

- (void)stopReading
{
    // 停止会话
    [_captureSession stopRunning];
    _captureSession = nil;
}

#pragma mark - AVCaptureMetadataOutputObjectsDelegate
// 获取捕获数据
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects
      fromConnection:(AVCaptureConnection *)connection
{
    if (metadataObjects != nil && [metadataObjects count] > 0) {
        
        AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0];
        NSString *result;
        if ([[metadataObj type] isEqualToString:AVMetadataObjectTypeQRCode]) {
            result = metadataObj.stringValue;
            [self performSelectorOnMainThread:@selector(reportScanResult:) withObject:result waitUntilDone:NO];
            
        } else {
            KTLog(@"不是二维码");
            [_captureSession startRunning];
        }
        
        
    }
    
}

// 处理结果
- (void)reportScanResult:(NSString *)result
{
    [self stopReading];
    
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"二维码扫描结果"
                                                        message:result
                                                       delegate:nil
                                              cancelButtonTitle:@"取消"
                                              otherButtonTitles: nil];
    
    [alert show];
}

并没有用到的闪光灯功能，并没有人会在关着灯的情况下进行扫描操作🐷

- (void)systemLightSwitch:(BOOL)open
{
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    if ([device hasTorch]) {
        [device lockForConfiguration:nil];
        if (open) {
            [device setTorchMode:AVCaptureTorchModeOn];
        } else {
            [device setTorchMode:AVCaptureTorchModeOff];
        }
        [device unlockForConfiguration];
    }
}