利用系统AV框架制作实现扫一扫功能（一行代码搞定）

Sian

1、先上图看看效果




2、设计思路
2.1、利用AVCaptureMetadataOutput固有的输出属性，能够输出二维码及条形码的解析结果
2.2、利用Quartz 2D绘出基本扫描界面，结合动画效果，简单又高效！2.3、只需两个类，一个控制器，一个视图：SAScanCtrl   SAScan
2.3、其他内容在代码中给出相关注释说明

3、部分代码
SAScanCtrl.h

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//
//  SAScanCtrl.h
// 
//
//  Created by 余西安 on 15/12/3.
//  Copyright © 2015年 Sian. All rights reserved.
//

#import <UIKit/UIKit.h>

typedef void (^SAScanBlock)(NSString *string);

@interface SAScanCtrl : UIViewController

@property (nonatomic, copy) SAScanBlock block;

- (instancetype)initWithBlock:(SAScanBlock)block;

@end

SAScanCtrl.m

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//
//  SAScanCtrl.m
//
//
//  Created by 余西安 on 15/12/3.
//  Copyright © 2015年 Sian. All rights reserved.
//

#import "SAScanCtrl.h"
#import "SAScan.h"
#import <AVFoundation/AVFoundation.h>

@interface SAScanCtrl ()<AVCaptureMetadataOutputObjectsDelegate>

@property (nonatomic, strong) AVCaptureSession *session;

@property (nonatomic, strong) AVAudioPlayer    *player;

@property (nonatomic, strong) SAScan           *scan;

@end

@implementation SAScanCtrl

- (instancetype)initWithBlock:(SAScanBlock)block
{
    if (self = [super init]){
        self.block = block;
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self.navigationItem setTitle:@"扫一扫"];
    
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc]init];
    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];   // 设置代理 在主线程里刷新
    [output setRectOfInterest:CGRectMake(0.12 , 0.12, 0.8, 0.8)];
    
    //初始化链接对象
    self.session = [[AVCaptureSession alloc] init];
    [self.session addInput:input];
    [self.session addOutput:output];
    [self.session setSessionPreset:AVCaptureSessionPresetHigh];
    //设置扫码支持的编码格式(如下设置条形码和二维码兼容)
    [output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode,AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code]];
    
    AVCaptureVideoPreviewLayer *layer = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
    layer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    layer.frame = self.view.bounds;

    [self.view.layer insertSublayer:layer atIndex:0];
    self.scan = [[SAScan alloc] initWithFrame:self.view.bounds];
    [self.view addSubview:self.scan];
    
    NSURL *url = [NSURL URLWithString:[[NSBundle mainBundle] pathForResource:@"scan" ofType:@"mp3"]];
    self.player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
    
    UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithTitle:@"重试" style:UIBarButtonItemStylePlain target:self action:@selector(startRunning)];
    [self.navigationItem setRightBarButtonItem:item];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self.session startRunning];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    [self.scan startAnimation];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    [self.session stopRunning];
}

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    if (metadataObjects.count > 0){
        AVMetadataMachineReadableCodeObject *metadataObject = [metadataObjects firstObject];
        [self.player play];
        [self.scan stopAnimation];
        [self.session stopRunning];
        if (self.block) self.block(metadataObject.stringValue);
        [self.navigationController popViewControllerAnimated:YES];
        [self dismissViewControllerAnimated:YES completion:nil];
    }
}

- (void)startRunning
{
    [self.session startRunning];
    [self.scan startAnimation];
}
@end

Scan.h

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//
//  SAScan.h
//
//
//  Created by 余西安 on 15/12/3.
//  Copyright © 2015年 Sian. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface SAScan : UIView

@property (nonatomic, strong) UIImageView *scanLine;

- (void)startAnimation;

- (void)stopAnimation;

@end

Scan.m

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//
//  SAScan.m
//
//
//  Created by 余西安 on 15/12/3.
//  Copyright © 2015年 Sian. All rights reserved.
//

#import "SAScan.h"

@implementation SAScan

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]){
        self.backgroundColor = [UIColor clearColor];
        UIImage *line = [UIImage imageNamed:@"scanLine.png"];
        self.scanLine = [[UIImageView alloc] initWithImage:line];
        [self.scanLine setHidden:YES];
        [self addSubview:self.scanLine];
    }
    return self;
}

- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();
    //非扫码区域半透明
    {
        CGFloat w = self.bounds.size.width * 0.7;
        CGFloat x = (self.bounds.size.width - w) * 0.5;
        CGFloat y = (self.bounds.size.height - w) * 0.5;
        {   // 外围区域填充半透明黑色
            // 设置非识别区域颜色
            CGContextSetRGBFillColor(context, 0, 0, 0, 0.6);
            
            // 扫码区域上面填充
            CGRect rect = CGRectMake(0, 0, self.frame.size.width, y);
            CGContextFillRect(context, rect);
            
            // 扫码区域左边填充
            rect = CGRectMake(0, y, x, w);
            CGContextFillRect(context, rect);
            
            // 扫码区域右边填充
            rect = CGRectMake(x + w, y, x, w);
            CGContextFillRect(context, rect);
            
            // 扫码区域下面填充
            rect = CGRectMake(0, y + w, self.frame.size.width, self.frame.size.height - y - w);
            CGContextFillRect(context, rect);
        }
        
        {   // 中间可视区域画边框
            UIColor *whiteColor = [UIColor colorWithWhite:1.0 alpha:0.5];
            CGContextSetStrokeColorWithColor(context, whiteColor.CGColor);
            CGContextSetLineWidth(context, 1);
            CGContextAddRect(context, CGRectMake(x, y, w, w));
            CGContextStrokePath(context);
        }
        
        
        {   // 中间可视区域画角框
            CGFloat lineWidth = 4.0f;
            CGFloat angleWidth = 15.0f;
            UIColor *greenColor = [UIColor colorWithRed:0 green:1.0 blue:0 alpha:0.8];
            CGContextSetLineWidth(context, lineWidth);
            CGContextSetStrokeColorWithColor(context, greenColor.CGColor);
            
            // 左上角
            CGContextMoveToPoint(context, x, y + angleWidth);
            CGContextAddLineToPoint(context, x, y);
            CGContextAddLineToPoint(context, x + angleWidth, y);
            // 右上角
            CGContextMoveToPoint(context, x + w - angleWidth, y);
            CGContextAddLineToPoint(context, x + w, y);
            CGContextAddLineToPoint(context, x + w, y + angleWidth);
            // 右下角
            CGContextMoveToPoint(context, x + w, y + w - angleWidth);
            CGContextAddLineToPoint(context, x + w, y + w);
            CGContextAddLineToPoint(context, x + w - angleWidth, y + w);
            // 左下角
            CGContextMoveToPoint(context, x + angleWidth, y + w);
            CGContextAddLineToPoint(context, x, y + w);
            CGContextAddLineToPoint(context, x, y + w - angleWidth);
        }
        CGContextStrokePath(context);
    }
}

- (void)layoutSubviews
{
    [super layoutSubviews];
    CGFloat width = self.bounds.size.width;
    CGFloat y = (self.bounds.size.height - width * 0.7) * 0.5;
    self.scanLine.frame = CGRectMake(0, y, width, 12);
}

- (void)startAnimation
{
    CGFloat width = self.bounds.size.width;
    CGFloat y = (self.bounds.size.height - width * 0.7) * 0.5;
    self.scanLine.frame = CGRectMake(0, y, width, 12);
    self.scanLine.hidden = NO;
    [UIView animateWithDuration:2.5 delay:0 options:UIViewAnimationOptionRepeat | UIViewAnimationOptionCurveLinear animations:^{
        self.scanLine.center = CGPointMake(width * 0.5, y + width * 0.7);
    } completion:^(BOOL finished) {
        if (finished) self.scanLine.center = CGPointMake(width * 0.5, y);
    }];
}

- (void)stopAnimation
{
    self.scanLine.hidden = YES;
    [self.scanLine.layer removeAllAnimations];
}
@end

4、使用只需一行代码：

    SAScanCtrl *scan = [[SAScanCtrl alloc] initWithBlock:^(NSString *string) {

        [[[UIAlertView alloc] initWithTitle:nil message:string delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil] show];

    }];

    UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:scan];

    [self presentViewController:nav animated:YES completion:nil];

5、Demo下载

游客，如果您要查看本帖隐藏内容请回复

豆丁00544

二维码扫描，，看看，，谢谢