IOS 扫二维码

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blog.csdn.net/hello_hwc

注意：本篇文章采用了IOS7的新特性来扫二维码，所以系统支持要IOS7以上，如果要兼容IOS7之前的版本，自行找库来支持。

为了方便，我把扫二维码简单封装到了一个UIView中，用代理的方式返回值

在使用之前，应当为工程添加AVFoundation.framework

最后实现的效果如图

完整的实现代码

头文件

////  HwcScanQRView.h//  HwcAnimationExample////  Created by huangwenchen on 15/1/7.//  Copyright (c) 2015年 huangwenchen. All rights reserved.//#import <UIKit/UIKit.h>@protocol HwcScanQRDelegate <NSObject>/*!* @discussion Delegate method when scan QR successed* @param QRContent Scan result* @return Void*/-(void)DidGetScanWithResult:(NSString *)QRContent;/*! * @discussion Delegate method when scan QR failed * @param error Error message * @return Void */-(void)DidFailToScanWithError:(NSError *)error;@end@interface HwcScanQRView : UIView@property id<HwcScanQRDelegate> delegate;@property(nonatomic,readonly) bool isScaning;-(BOOL)startScaning;-(void)stop;@end

.m文件

////  HwcScanQRView.m//  HwcAnimationExample////  Created by huangwenchen on 15/1/7.//  Copyright (c) 2015年 huangwenchen. All rights reserved.//#import "HwcScanQRView.h"#import  <AVFoundation/AVFoundation.h>@interface HwcScanQRView()<AVCaptureMetadataOutputObjectsDelegate>@property(nonatomic,readwrite) bool isScaning;@property(strong,nonatomic)AVCaptureSession * captureSession;@property(strong,nonatomic)AVCaptureVideoPreviewLayer * vedioPreviewLayer;@end@implementation HwcScanQRView#pragma mark - Propertys-(AVCaptureSession *)captureSession{    if (!_captureSession) {        _captureSession = [[AVCaptureSession alloc] init];    }    return  _captureSession;}-(AVCaptureVideoPreviewLayer *)vedioPreviewLayer{    if (!_vedioPreviewLayer) {        _vedioPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];    }    return _vedioPreviewLayer;}#pragma mark - QRScan function-(BOOL)startScaning{    NSError * error;    AVCaptureDevice * captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];    AVCaptureDeviceInput * deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];    if (!deviceInput) {        if ([self.delegate respondsToSelector:@selector(DidFailToScanWithError:)]) {            [self.delegate DidFailToScanWithError:error];        }        return NO;    }    [self.captureSession addInput:deviceInput];    AVCaptureMetadataOutput * captureMetadataOutput = [[AVCaptureMetadataOutput alloc] init];    [self.captureSession addOutput:captureMetadataOutput];    dispatch_queue_t scanQRqueue;    scanQRqueue = dispatch_queue_create("scanQRqueue",DISPATCH_QUEUE_SERIAL);    [captureMetadataOutput setMetadataObjectsDelegate:self queue:scanQRqueue];    [captureMetadataOutput setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];    [self.vedioPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];    [self.vedioPreviewLayer setFrame:self.layer.bounds];    [self.layer addSublayer:self.vedioPreviewLayer];    [self.captureSession startRunning];    return YES;}-(void)stop{    [self.captureSession stopRunning];    self.isScaning = NO;    self.captureSession = nil;    [_vedioPreviewLayer removeFromSuperlayer];}#pragma mark - AVFoundation delegate method-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{    if (metadataObjects != nil && metadataObjects.count > 0) {        AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects firstObject];        if ([[metadataObject type] isEqualToString:AVMetadataObjectTypeQRCode]) {            NSString * scanResult = [metadataObject stringValue];            dispatch_async(dispatch_get_main_queue(), ^{                if ([self.delegate respondsToSelector:@selector(DidGetScanWithResult:)]) {                    [self.delegate DidGetScanWithResult:scanResult];                }            });        }    }}@end

在使用的类中

////  ViewController.m//  HwcAnimationExample////  Created by huangwenchen on 15/1/6.//  Copyright (c) 2015年 huangwenchen. All rights reserved.//#import "ViewController.h"#import "HwcScanQRView.h"@interface ViewController ()<HwcScanQRDelegate>//这里实现代理@property (strong,nonatomic)UILabel * scanresultLabel;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    HwcScanQRView * scanView = [[HwcScanQRView alloc] initWithFrame:CGRectMake(100,100,200, 200)];    scanView.delegate = self;//这一步必须的    [self.view addSubview:scanView];    self.scanresultLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 320, 200, 30)];    [self.view addSubview:self.scanresultLabel];    [scanView startScaning];//不要忘记开始扫描}//两个代理方法-(void)DidGetScanWithResult:(NSString *)QRContent{    self.scanresultLabel.text = QRContent;}-(void)DidFailToScanWithError:(NSError *)error{    NSLog(@"%@",error.localizedDescription);}@end