ios最简洁二维码扫描以及跳转

实现了二维码扫描获取数据，扫描范围的确定，实现扫码框，扫码时的动画效果以及扫码成功后跳转。

参考链接：http://blog.youkuaiyun.com/huanghao12/article/details/50472125

.h文件

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>

@interface QRcodeViewController : UIViewController<AVCaptureMetadataOutputObjectsDelegate>

@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;

@end

.m文件

#import "QRcodeViewController.h"

#define QRCodeWidth  260.0   //正方形二维码框的边长

@interface QRcodeViewController ()

@end

@implementation QRcodeViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [self setNav];

    // Device
    _device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    // Input
    _input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];

    // Output
    _output = [[AVCaptureMetadataOutput alloc]init];
    [_output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    //设置扫描区域，x与y对换了，宽与高也对换了
    //特别注意的地方：有效的扫描区域，定位是以设置的右顶点为原点。屏幕宽所在的那条线为y轴，屏幕高所在的线为x轴
    CGFloat x = ((SCREEN_HEIGHT-QRCodeWidth-64)/2.0)/SCREEN_HEIGHT;
    CGFloat y = ((SCREEN_WIDTH-QRCodeWidth)/2.0)/SCREEN_WIDTH;
    CGFloat width = QRCodeWidth/SCREEN_HEIGHT;
    CGFloat height = QRCodeWidth/SCREEN_WIDTH;
    _output.rectOfInterest = CGRectMake(x, y, width, height);


    // Session
    _session = [[AVCaptureSession alloc]init];
    [_session setSessionPreset:AVCaptureSessionPresetHigh];
    if ([_session canAddInput:self.input])
    {
        [_session addInput:self.input];
    }

    if ([_session canAddOutput:self.output])
    {
        [_session addOutput:self.output];
    }

//    条码类型 AVMetadataObjectTypeQRCode
    _output.metadataObjectTypes =@[AVMetadataObjectTypeQRCode];

    // Preview
    _preview =[AVCaptureVideoPreviewLayer layerWithSession:_session];
    _preview.videoGravity =AVLayerVideoGravityResizeAspectFill;
    _preview.frame =self.view.layer.bounds;
    [self.view.layer insertSublayer:_preview atIndex:0];


    //扫描框
    [self setupMaskView];

    //扫描动画
    [self setupScanWindowView];

    // Start
    [_session startRunning];
}

- (void)setupMaskView
{
    //设置统一的视图颜色和视图的透明度
    UIColor *color = [UIColor blackColor];
    float alpha = 0.7;

    //设置扫描区域外部上部的视图
    UIView *topView = [[UIView alloc]init];
    topView.frame = CGRectMake(0, 64, SCREEN_WIDTH, (SCREEN_HEIGHT-64-QRCodeWidth)/2.0-64);
    topView.backgroundColor = color;
    topView.alpha = alpha;

    //设置扫描区域外部左边的视图
    UIView *leftView = [[UIView alloc]init];
    leftView.frame = CGRectMake(0, 64+topView.frame.size.height, (SCREEN_WIDTH-QRCodeWidth)/2.0,QRCodeWidth);
    leftView.backgroundColor = color;
    leftView.alpha = alpha;

    //设置扫描区域外部右边的视图
    UIView *rightView = [[UIView alloc]init];
    rightView.frame = CGRectMake((SCREEN_WIDTH-QRCodeWidth)/2.0+QRCodeWidth,64+topView.frame.size.height, (SCREEN_WIDTH-QRCodeWidth)/2.0,QRCodeWidth);
    rightView.backgroundColor = color;
    rightView.alpha = alpha;

    //设置扫描区域外部底部的视图
    UIView *botView = [[UIView alloc]init];
    botView.frame = CGRectMake(0, 64+QRCodeWidth+topView.frame.size.height,SCREEN_WIDTH,SCREEN_HEIGHT-64-QRCodeWidth-topView.frame.size.height);
    botView.backgroundColor = color;
    botView.alpha = alpha;

    //将设置好的扫描二维码区域之外的视图添加到视图图层上
    [self.view addSubview:topView];
    [self.view addSubview:leftView];
    [self.view addSubview:rightView];
    [self.view addSubview:botView];
}

- (void)setupScanWindowView
{
    //设置扫描区域的位置(考虑导航栏和电池条的高度为64)
    UIView *scanWindow = [[UIView alloc]initWithFrame:CGRectMake((SCREEN_WIDTH-QRCodeWidth)/2.0,(SCREEN_HEIGHT-QRCodeWidth-64)/2.0,QRCodeWidth,QRCodeWidth)];
    scanWindow.clipsToBounds = YES;
    [self.view addSubview:scanWindow];

    //设置扫描区域的动画效果
    CGFloat scanNetImageViewH = 3;
    CGFloat scanNetImageViewW = scanWindow.frame.size.width;
    UIImageView *scanNetImageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"光线"]];
    scanNetImageView.frame = CGRectMake(0, -scanNetImageViewH, scanNetImageViewW, scanNetImageViewH);
    scanNetImageView.backgroundColor = [UIColor clearColor];
    CABasicAnimation *scanNetAnimation = [CABasicAnimation animation];
    scanNetAnimation.keyPath =@"transform.translation.y";
    scanNetAnimation.byValue = @(QRCodeWidth);
    scanNetAnimation.duration = 3.0;
    scanNetAnimation.repeatCount = MAXFLOAT;
    [scanNetImageView.layer addAnimation:scanNetAnimation forKey:nil];
    [scanWindow addSubview:scanNetImageView];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)setNav
{
    [self.navigationItem setTitle:@"二维码"];
    UIBarButtonItem *leftBtn = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(goBack)];

    [self.navigationItem setLeftBarButtonItem:leftBtn];
}

- (void)goBack
{
    [self dismissViewControllerAnimated:YES completion:nil];
}

//然后实现 AVCaptureMetadataOutputObjectsDelegate
#pragma mark AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    NSString *stringValue;
    if ([metadataObjects count] >0)
    {
        //停止扫描
        [_session stopRunning];
        AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex:0];
        stringValue = metadataObject.stringValue;
        NSLog(@"%@",stringValue);
        NSURL * url = [NSURL URLWithString: stringValue];
        if ([[UIApplication sharedApplication] canOpenURL: url]) {
            [[UIApplication sharedApplication] openURL: url];
        }else{
            [Message showMessage:[NSString stringWithFormat:@"无法解析url：%@",stringValue]];
        }

    }

}

@end