iOS 扫一扫功能实现 —— HERO博客

调用系统原生接口实现扫一扫功能，可扫描识别二维码、条形码，识别相册图片。

首先看一下效果图：



下面贴上代码：

（如果测试机系统10.0及以上，在Info.plist文件添加如下语句：Privacy - Camera Usage Description、Privacy - Photo Library Usage Description。

可参考我之前的一篇博客，iOS 10.0系统麦克风、相机等权限崩溃问题解决。）

AppDelegate.m：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:[[ViewController alloc] init]];
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];

return YES;
}

ViewController：

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@end

/*** ---------------分割线--------------- ***/

#import "ViewController.h"
#import "HWScanViewController.h"

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

self.view.backgroundColor = [UIColor whiteColor];

//创建控件
[self creatControl];
}

- (void)creatControl
{
//扫一扫按钮
UIButton *scanBtn = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 100, 44)];
scanBtn.backgroundColor = [UIColor orangeColor];
[scanBtn setTitle:@"扫一扫" forState:UIControlStateNormal];
[scanBtn addTarget:self action:@selector(scanBtnOnClick) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:scanBtn];
}

- (void)scanBtnOnClick
{
HWScanViewController *vc = [[HWScanViewController alloc] init];
[self.navigationController pushViewController:vc animated:YES];
}

@end

HWScanViewController：

#import <UIKit/UIKit.h>

@interface HWScanViewController : UIViewController

@end

/*** ---------------分割线--------------- ***/

#import "HWScanViewController.h"
#import <AVFoundation/AVFoundation.h>

#define KMainW [UIScreen mainScreen].bounds.size.width
#define KMainH [UIScreen mainScreen].bounds.size.height

@interface HWScanViewController ()<AVCaptureMetadataOutputObjectsDelegate, UINavigationControllerDelegate, UIImagePickerControllerDelegate>

@property (nonatomic, strong) NSTimer *timer;
@property (nonatomic, strong) AVCaptureDevice *device;
@property (nonatomic, strong) AVCaptureSession *session;
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *preview;
@property (nonatomic, weak) UIImageView *line;
@property (nonatomic, assign) NSInteger distance;

@end

@implementation HWScanViewController

- (void)viewDidLoad {
[super viewDidLoad];

//初始化信息
[self initInfo];

//创建控件
[self creatControl];

//设置参数
[self setupCamera];

//添加定时器
[self addTimer];
}

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

[self stopScanning];
}

- (void)initInfo
{
//背景色
self.view.backgroundColor = [UIColor blackColor];

//导航标题
self.navigationItem.title = @"二维码/条形码";

//导航右侧相册按钮
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"相册" style:UIBarButtonItemStylePlain target:self action:@selector(photoBtnOnClick)];
}

- (void)creatControl
{
CGFloat scanW = KMainW * 0.65;
CGFloat padding = 10.0f;
CGFloat labelH = 20.0f;
CGFloat tabBarH = 64.0f;
CGFloat cornerW = 26.0f;
CGFloat marginX = (KMainW - scanW) * 0.5;
CGFloat marginY = (KMainH - scanW - padding - labelH) * 0.5;

//遮盖视图
for (int i = 0; i < 4; i++) {
UIView *cover = [[UIView alloc] initWithFrame:CGRectMake(0, (marginY + scanW) * i, KMainW, marginY + (padding + labelH) * i)];
if (i == 2 || i == 3) {
cover.frame = CGRectMake((marginX + scanW) * (i - 2), marginY, marginX, scanW);
}
cover.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.5f];
[self.view addSubview:cover];
}

//扫描视图
UIView *scanView = [[UIView alloc] initWithFrame:CGRectMake(marginX, marginY, scanW, scanW)];
[self.view addSubview:scanView];

//扫描线
UIImageView *line = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, scanW, 2)];
[self drawLineForImageView:line];
[scanView addSubview:line];
self.line = line;

//边框
UIView *borderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, scanW, scanW)];
borderView.layer.borderColor = [[UIColor whiteColor] CGColor];
borderView.layer.borderWidth = 1.0f;
[scanView addSubview:borderView];

//扫描视图四个角
for (int i = 0; i < 4; i++) {
CGFloat imgViewX = (scanW - cornerW) * (i % 2);
CGFloat imgViewY = (scanW - cornerW) * (i / 2);
UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectMake(imgViewX, imgViewY, cornerW, cornerW)];
if (i == 0 || i == 1) {
imgV
4000
iew.transform = CGAffineTransformRotate(imgView.transform, M_PI_2 * i);
}else {
imgView.transform = CGAffineTransformRotate(imgView.transform, - M_PI_2 * (i - 1));
}
[self drawImageForImageView:imgView];
[scanView addSubview:imgView];
}

//提示标签
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, CGRectGetMaxY(scanView.frame) + padding, KMainW, labelH)];
label.text = @"将二维码/条形码放入框内，即可自动扫描";
label.font = [UIFont systemFontOfSize:16.0f];
label.textAlignment = NSTextAlignmentCenter;
label.textColor = [UIColor whiteColor];
[self.view addSubview:label];

//选项栏
UIView *tabBarView = [[UIView alloc] initWithFrame:CGRectMake(0, KMainH - tabBarH, KMainW, tabBarH)];
tabBarView.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.8f];
[self.view addSubview:tabBarView];

//开启照明按钮
UIButton *lightBtn = [[UIButton alloc] initWithFrame:CGRectMake(KMainW - 100, 0, 100, tabBarH)];
lightBtn.titleLabel.font = [UIFont systemFontOfSize:16.0f];
[lightBtn setTitle:@"开启照明" forState:UIControlStateNormal];
[lightBtn setTitle:@"关闭照明" forState:UIControlStateSelected];
[lightBtn addTarget:self action:@selector(lightBtnOnClick:) forControlEvents:UIControlEventTouchUpInside];
[tabBarView addSubview:lightBtn];
}

- (void)setupCamera
{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//初始化相机设备
_device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

//初始化输入流
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:_device error:nil];

//初始化输出流
AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
//设置代理，主线程刷新
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

//初始化链接对象
_session = [[AVCaptureSession alloc] init];
//高质量采集率
[_session setSessionPreset:AVCaptureSessionPresetHigh];

if ([_session canAddInput:input]) [_session addInput:input];
if ([_session canAddOutput:output]) [_session addOutput:output];

//条码类型（二维码/条形码）
output.metadataObjectTypes = [NSArray arrayWithObjects:AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code, AVMetadataObjectTypeQRCode, nil];

//更新界面
dispatch_async(dispatch_get_main_queue(), ^{
_preview = [AVCaptureVideoPreviewLayer layerWithSession:_session];
_preview.videoGravity = AVLayerVideoGravityResizeAspectFill;
_preview.frame = CGRectMake(0, 0, KMainW, KMainH);
[self.view.layer insertSublayer:_preview atIndex:0];
[_session startRunning];
});
});
}

- (void)addTimer
{
_distance = 0;
self.timer = [NSTimer scheduledTimerWithTimeInterval:0.01f target:self selector:@selector(timerAction) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
}

- (void)timerAction
{
if (_distance++ > KMainW * 0.65) _distance = 0;
_line.frame = CGRectMake(0, _distance, KMainW * 0.65, 2);
}

- (void)removeTimer
{
[_timer invalidate];
_timer = nil;
}

//照明按钮点击事件
- (void)lightBtnOnClick:(UIButton *)btn
{
//判断是否有闪光灯
if (![_device hasTorch]) {
[self showAlertWithTitle:@"当前设备没有闪光灯，无法开启照明功能" message:nil sureHandler:nil cancelHandler:nil];
return;
}

btn.selected = !btn.selected;

[_device lockForConfiguration:nil];
if (btn.selected) {
[_device setTorchMode:AVCaptureTorchModeOn];
}else {
[_device setTorchMode:AVCaptureTorchModeOff];
}
[_device unlockForConfiguration];
}

//进入相册
- (void)photoBtnOnClick
{
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
UIImagePickerController *controller = [[UIImagePickerController alloc] init];
controller.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
controller.delegate = self;

[self presentViewController:controller animated:YES completion:nil];
}else {
[self showAlertWithTitle:@"当前设备不支持访问相册" message:nil sureHandler:nil cancelHandler:nil];
}
}

#pragma mark - AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
//扫描完成
if ([metadataObjects count] > 0) {
//停止扫描
[self stopScanning];
//显示结果
[self showAlertWithTitle:@"扫描结果" message:[[metadataObjects firstObject] stringValue] sureHandler:nil cancelHandler:nil];
}
}

- (void)stopScanning
{
[_session stopRunning];
_session = nil;
[_preview removeFromSuperlayer];
[self removeTimer];
}

#pragma mark - UIImagePickerControllrDelegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
[picker dismissViewControllerAnimated:YES completion:^{
//获取相册图片
UIImage *image = info[UIImagePickerControllerOriginalImage];

//识别图片
CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:@{CIDetectorAccuracy:CIDetectorAccuracyHigh}];
NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:image.CGImage]];

//识别结果
if (features.count > 0) {
[self showAlertWithTitle:@"扫描结果" message:[[features firstObject] messageString] sureHandler:nil cancelHandler:nil];

}else{
[self showAlertWithTitle:@"没有识别到二维码或条形码" message:nil sureHandler:nil cancelHandler:nil];
}
}];
}

//提示弹窗
- (void)showAlertWithTitle:(NSString *)title message:(NSString *)message sureHandler:(void (^)())sureHandler cancelHandler:(void (^)())cancelHandler
{
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *sureAction = [UIAlertAction actionWithTitle:@"确认" style:UIAlertActionStyleDefault handler:sureHandler];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:cancelHandler];
[alertController addAction:sureAction];
[alertController addAction:cancelAction];

[self presentViewController:alertController animated:YES completion:nil];
}

//绘制角图片
- (void)drawImageForImageView:(UIImageView *)imageView
{
UIGraphicsBeginImageContext(imageView.bounds.size);

//获取上下文
CGContextRef context = UIGraphicsGetCurrentContext();
//设置线条宽度
CGContextSetLineWidth(context, 6.0f);
//设置颜色
CGContextSetStrokeColorWithColor(context, [[UIColor greenColor] CGColor]);
//路径
CGContextBeginPath(context);
//设置起点坐标
CGContextMoveToPoint(context, 0, imageView.bounds.size.height);
//设置下一个点坐标
CGContextAddLineToPoint(context, 0, 0);
CGContextAddLineToPoint(context, imageView.bounds.size.width, 0);
//渲染，连接起点和下一个坐标点
CGContextStrokePath(context);

imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}

//绘制线图片
- (void)drawLineForImageView:(UIImageView *)imageView
{
CGSize size = imageView.bounds.size;
UIGraphicsBeginImageContext(size);

//获取上下文
CGContextRef context = UIGraphicsGetCurrentContext();
//创建一个颜色空间
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
//设置开始颜色
const CGFloat *startColorComponents = CGColorGetComponents([[UIColor greenColor] CGColor]);
//设置结束颜色
const CGFloat *endColorComponents = CGColorGetComponents([[UIColor whiteColor] CGColor]);
//颜色分量的强度值数组
CGFloat components[8] = {startColorComponents[0], startColorComponents[1], startColorComponents[2], startColorComponents[3], endColorComponents[0], endColorComponents[1], endColorComponents[2], endColorComponents[3]
};
//渐变系数数组
CGFloat locations[] = {0.0, 1.0};
//创建渐变对象
CGGradientRef gradient = CGGradientCreateWithColorComponents(colorSpace, components, locations, 2);
//绘制渐变
CGContextDrawRadialGradient(context, gradient, CGPointMake(size.width * 0.5, size.height * 0.5), size.width * 0.25, CGPointMake(size.width * 0.5, size.height * 0.5), size.width * 0.5, kCGGradientDrawsBeforeStartLocation);
//释放
CGColorSpaceRelease(colorSpace);
CGGradientRelease(gradient);

imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}

@end

扫一扫Demo下载链接：http://code.cocoachina.com/view/134257