需求：产品要实现类似微信扫码一样效果的功能，光线暗的时候，能够自动打开闪光灯（并出现闪光灯控制开关图标），然后用户可以手动控制闪光灯的开关。
还有一个是实现自动拉近放大功能。
1.png
踩过的坑：当时不知道是手冻还是什么，把videoPreView的引用类型写成了weak，导致了镜头所在的layer加载不显示，当时查了好久没找到问题，心态崩了，找的小伙伴帮我排查，最后他打断点发现打印self.videoPreView的frame为（0，0，0，0）。我又自己看了一下，发现self.videoPreView为nil，就看了一下属性。果然是属性写错了，以后一定要谨慎细心。真丢脸啊😓
#import "QRCodeScanningViewController.h"
#import <AVFoundation/AVFoundation.h>
#import <ImageIO/ImageIO.h>
#import "GoodsDetailViewController.h"
@interface QRCodeScanningViewController ()<AVCaptureMetadataOutputObjectsDelegate,AVCaptureVideoDataOutputSampleBufferDelegate,UIGestureRecognizerDelegate>{
BOOL bHadAutoVideoZoom;
}
@property (weak, nonatomic) IBOutlet UIButton *torchBtn;//灯泡开关
@property (weak, nonatomic) IBOutlet UILabel *torchStatusLabel;//灯泡底下的开关显示
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *scanBottomConstraint;
@property (weak, nonatomic) IBOutlet UIImageView *scanningBar;
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *leftReturnBtnTopConstraint;
@property (nonatomic, strong) NSTimer *timer;
@property (nonatomic, strong) AVCaptureDevice *device;
@property (nonatomic, strong) AVCaptureSession *session;
@property (strong, nonatomic) AVCaptureDeviceInput * input;
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *layer;
@property (nonatomic, strong) AVCaptureStillImageOutput *stillImageOutput;//拍照
@property (nonatomic, strong) UIView *videoPreView; ///视频预览显示视图
@property (nonatomic, assign) CGPoint centerPoint;//二维码的中心点
@property (nonatomic, assign) BOOL isAutoOpen;//默认NO 闪光灯
@end
@implementation QRCodeScanningViewController
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
self.navigationController.navigationBar.hidden = YES;
}
- (void)viewWillDisappear:(BOOL)animated{
[super viewWillDisappear:animated];
self.navigationController.navigationBar.hidden = NO;
[self turnTorchOn:NO];
[self stopScanning];
}
- (void)viewDidLoad {
[super viewDidLoad];
[self creatSubviews];
[self scanCameraAuth];
}
#pragma mark - UI
- (void)creatSubviews{
//默认不显示闪光灯
[self.torchBtn setSelected:NO];
self.torchBtn.hidden = self.torchStatusLabel.hidden =YES;
//适配齐刘海
self.leftReturnBtnTopConstraint.constant = (6+STATUSH);
}
- (void)scanCameraAuth{
__weak typeof(self) weakSelf = self;
[self requestCameraPemissionWithResult:^(BOOL granted) {
if (granted) {
[weakSelf startScanning];
[weakSelf networkStatusAlert];
} else {
[weakSelf showAlertToPromptCameraAuthorization];
}
}];
}
#pragma mark - btn
- (IBAction)returnBack:(UIButton *)sender {
[self leftBarButtonItemReturnAction];
}
- (IBAction)lighting:(UIButton *)sender {
sender.selected = !sender.selected;
[self turnTorchOn:sender.selected];
}
#pragma mark - Helpers
- (void)startScanning {
self.timer = [NSTimer scheduledTimerWithTimeInterval:0.02 target:self selector:@selector(animateScanningBar) userInfo:nil repeats:YES];
if (!self.layer) {
AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetHigh;
/// Input.
self.device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
self.input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];
/// Output. Must work in a serial queue.
dispatch_queue_t serialQueue = dispatch_queue_create("ScanningQueue", NULL);
//扫描结果 自动放大
AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
[output setMetadataObjectsDelegate:self queue:serialQueue];
//闪光灯
AVCaptureVideoDataOutput *dataOutput = [[AVCaptureVideoDataOutput alloc] init];
[dataOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
// CGRect cropRect = CGRectMake((SCREEN_WIDTH-220)*0.5, SCREEN_HEIGHT*0.5-60, 220, 220);
// if (!CGRectEqualToRect(cropRect,CGRectZero)){
// output.rectOfInterest = cropRect;
// }
self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG, AVVideoCodecKey,nil];
[self.stillImageOutput setOutputSettings:outputSettings];
if ([session canAddInput:self.input]) {
[session addInput:self.input];
}
if ([session canAddOutput:output]) {
[session addOutput:output];
}
if ([session canAddOutput:dataOutput]) {
[session addOutput:dataOutput];
}
if ([session canAddOutput:self.stillImageOutput]){
[session addOutput:self.stillImageOutput];
}
/* 扫条形码
AVMetadataObjectTypeEAN13Code,
AVMetadataObjectTypeEAN8Code,
AVMetadataObjectTypeUPCECode,
AVMetadataObjectTypeCode39Code,
AVMetadataObjectTypeCode39Mod43Code,
AVMetadataObjectTypeCode93Code,
AVMetadataObjectTypeCode128Code,
AVMetadataObjectTypePDF417Code
*/
NSArray *types = @[AVMetadataObjectTypeQRCode];
NSMutableArray *typesAvailable = [NSMutableArray array];
for (NSString *type in types) {
if ([output.availableMetadataObjectTypes containsObject:type]) [typesAvailable addObject:type];
}
output.metadataObjectTypes = typesAvailable;
/// Preview layer.
AVCaptureVideoPreviewLayer *layer = [AVCaptureVideoPreviewLayer layerWithSession:session];
layer.videoGravity = AVLayerVideoGravityResizeAspectFill;
layer.frame = SCREEN_BOUNDS;
[self.view insertSubview:self.videoPreView atIndex:0];
[self.videoPreView.layer insertSublayer:layer atIndex:0];
self.layer = layer;
self.session = session;
}
[self.session startRunning];
bHadAutoVideoZoom = NO;//还未自动拉近的值
[self setVideoScale:1 ];//设置拉近倍数为1
}
- (void)stopScanning {
if (self.session.isRunning) {
[self.session stopRunning];
}
if (self.timer.isValid) {
[self.timer invalidate];
self.timer = nil;
}
}
- (void)animateScanningBar {
int constant = (int)self.scanBottomConstraint.constant;
if (constant > 0) {
constant --;
}else {
constant = 218;
}
self.scanBottomConstraint.constant = constant;
}
#pragma mark - get
- (UIView *)videoPreView{
if (!_videoPreView) {
UIView *videoView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT)];
videoView.backgroundColor = [UIColor clearColor];
_videoPreView = videoView;
}
return _videoPreView;
}
#pragma mark - Delegate Methods AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection {
NetworkStatus internetStatus = [Helper internetStatus];
if (internetStatus == NotReachable) {
return;
}
//识别扫码类型
NSString *result;
for(AVMetadataObject *current in metadataObjects){
if ([current isKindOfClass:[AVMetadataMachineReadableCodeObject class]]){
NSString *scannedResult = [(AVMetadataMachineReadableCodeObject *) current stringValue];
if (scannedResult && ![scannedResult isEqualToString:@""]){
result = scannedResult;
}
}
}
// NSLog(@"扫描%@", result);
if (result.length<1) {
return;
}
if (!bHadAutoVideoZoom) {
AVMetadataMachineReadableCodeObject *obj = (AVMetadataMachineReadableCodeObject *)[self.layer transformedMetadataObjectForMetadataObject:metadataObjects.lastObject];
dispatch_async(dispatch_get_main_queue(), ^{
[self changeVideoScale:obj];
});
bHadAutoVideoZoom =YES;
return;
}
if ([result hasPrefix:@"https"]||[result hasPrefix:@"http"]) {
[self stopScanning];
dispatch_async(dispatch_get_main_queue(), ^{
[self handlerJump:result];
});
}else{
__weak typeof(self) weakSelf = self;
dispatch_async(dispatch_get_main_queue(), ^{
[Helper addAlerViewOrAlertControllerWithTitle:@"提示" message: @"无效的二维码" buttonTitle:@"我知道了" forViewController:weakSelf];
});
}
}
//处理跳转
- (void)handlerJump:(NSString *)resultString{
NSDictionary *dic = [NSDictionary dictionaryWithDictionary:[Helper getDictionaryFormURL:resultString]];
if(![resultString containsString:@"nqyong.com"]){
__weak typeof(self) weakSelf = self;
NSString *msg = [NSString stringWithFormat:@"可能存在安全风险，是否打开此链接？\n%@",resultString];
[self addTwoAlertControllerAction:@"提示" message:msg leftTitle:@"打开链接" rightTitle:@"取消" leftAction:^(UIAlertAction * _Nonnull action) {
[weakSelf passScanningGoNextBaseWebviewTitle:@"" updateTitle:YES url:resultString contactKefu:NO];
} rightAction:^(UIAlertAction * _Nonnull action) {
[weakSelf leftBarButtonItemReturnAction];
}];
}else if ([resultString containsString:@"www.nqyong.com/downloadsApp.html"]){
NSString *jumpString = [NSString stringWithFormat:@"https://store-h5.nqyong.com/channelShop?appid=%@",dic[@"appid"]];
[self passScanningGoNextBaseWebviewTitle:@"商品列表" updateTitle:YES url:jumpString contactKefu:NO];
}else if ([resultString containsString:@"h5.nqyong.com/goodsDetail?"]) {
GoodsDetailViewController *GoodsDetailVC = (GoodsDetailViewController *)[UIStoryboard vcFrom:Goods identifier:[NSString stringWithFormat:@"%@",GoodsDetailViewController.class]];
GoodsDetailVC.hidesBottomBarWhenPushed = YES;
GoodsDetailVC.goodsID = dic[@"id"];
GoodsDetailVC.goodsName = @"";
[DataKeeper sharedKeeper].appId = dic[@"appid"];
[self passScanningGoNextVC:GoodsDetailVC];
}else{
[self passScanningGoNextBaseWebviewTitle:@"" updateTitle:YES url:resultString contactKefu:NO];
}
}
//跳转到webview之前，去掉扫码页
- (void)passScanningGoNextBaseWebviewTitle:(NSString *)title updateTitle:(BOOL)updateTitle url:(NSString *)url contactKefu:(BOOL)contactKefu{
if (url.length == 0) return;
RootWebViewController *root = [[RootWebViewController alloc]init];
root.hidesBottomBarWhenPushed = YES;
root.aTitle = title;
root.contactKefu = contactKefu;
root.updateTitle = updateTitle;
root.request = [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
[self passScanningGoNextVC:root];
}
//设置navabar的代理路由
- (void)passScanningGoNextVC:(UIViewController *)vc{
NSMutableArray *vcArray = [NSMutableArray arrayWithArray:self.navigationController.viewControllers];
int index = (int)[vcArray indexOfObject:self];
if (vcArray.count<2) {
return;
}
[vcArray removeObjectAtIndex:index];
[vcArray addObject: vc];
[self.navigationController setViewControllers:vcArray animated:NO];
}
#pragma mark - AVCaptureVideoDataOutputSampleBufferDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{
CFDictionaryRef metadataDict = CMCopyDictionaryOfAttachments(NULL,sampleBuffer, kCMAttachmentMode_ShouldPropagate);
NSDictionary *metadata = [[NSMutableDictionary alloc] initWithDictionary:(__bridge NSDictionary*)metadataDict];
CFRelease(metadataDict);
NSDictionary *exifMetadata = [[metadata objectForKey:(NSString *)kCGImagePropertyExifDictionary] mutableCopy];
float brightnessValue = [[exifMetadata objectForKey:(NSString *)kCGImagePropertyExifBrightnessValue] floatValue];
// brightnessValue 值代表光线强度，值越小代表光线越暗
// NSLog(@"光线%f", brightnessValue);
if (brightnessValue <= -2 &&!self.isAutoOpen) {
self.isAutoOpen = YES;
[self turnTorchOn:YES];
dispatch_async(dispatch_get_main_queue(), ^{
[self.torchBtn setSelected:YES];
self.torchBtn.hidden = self.torchStatusLabel.hidden= NO;
});
}
}
#pragma mark - 打开/关闭手电筒
- (void)turnTorchOn:(BOOL)on{
if ([self.device hasTorch] && [self.device hasFlash]){
dispatch_async(dispatch_get_main_queue(), ^{
self.torchStatusLabel.text = on?@"点击关闭":@"点击开启";
});
[self.device lockForConfiguration:nil];
if (on) {
[self.device setTorchMode:AVCaptureTorchModeOn];
[self.device setFlashMode:AVCaptureFlashModeOn];
} else {
[self.device setTorchMode:AVCaptureTorchModeOff];
[self.device setFlashMode:AVCaptureFlashModeOff];
}
[self.device unlockForConfiguration];
} else {
[Helper addAlerViewOrAlertControllerWithTitle:@"提示" message:@"当前设备没有闪光灯，不能提供手电筒功能" buttonTitle:@"我知道了" forViewController:self];
}
}
#pragma mark - 二维码自动拉近
- (void)changeVideoScale:(AVMetadataMachineReadableCodeObject *)objc
{
NSArray *array = objc.corners;
NSLog(@"cornersArray = %@",array);
CGPoint point = CGPointZero;
// 把字典转换为点，存在point里，成功返回true 其他false
CGPointMakeWithDictionaryRepresentation((__bridge CFDictionaryRef)array[0], &point);
NSLog(@"X:%f -- Y:%f",point.x,point.y);
CGPoint point2 = CGPointZero;
CGPointMakeWithDictionaryRepresentation((__bridge CFDictionaryRef)array[2], &point2);
NSLog(@"X:%f -- Y:%f",point2.x,point2.y);
self.centerPoint = CGPointMake((point.x + point2.x) / 2, (point.y + point2.y) / 2);
CGFloat scace = 150 / (point2.x - point.x); //当二维码图片宽小于150，进行放大
[self setVideoScale:scace];
return;
}
- (void)setVideoScale:(CGFloat)scale
{
[self.input.device lockForConfiguration:nil];
AVCaptureConnection *videoConnection = [self connectionWithMediaType:AVMediaTypeVideo fromConnections:[[self stillImageOutput] connections]];
CGFloat maxScaleAndCropFactor = ([[self.stillImageOutput connectionWithMediaType:AVMediaTypeVideo] videoMaxScaleAndCropFactor])/16;
if (scale > maxScaleAndCropFactor){
scale = maxScaleAndCropFactor;
}else if (scale < 1){
scale = 1;
}
CGFloat zoom = scale / videoConnection.videoScaleAndCropFactor;
videoConnection.videoScaleAndCropFactor = scale;
[self.input.device unlockForConfiguration];
CGAffineTransform transform = self.videoPreView.transform;
//自动拉近放大
if (scale == 1) {
self.videoPreView.transform = CGAffineTransformScale(transform, zoom, zoom);
CGRect rect = self.videoPreView.frame;
rect.origin = CGPointZero;
self.videoPreView.frame = rect;
} else {
CGFloat x = self.videoPreView.center.x - self.centerPoint.x;
CGFloat y = self.videoPreView.center.y - self.centerPoint.y;
CGRect rect = self.videoPreView.frame;
rect.origin.x = rect.size.width / 2.0 * (1 - scale);
rect.origin.y = rect.size.height / 2.0 * (1 - scale);
rect.origin.x += x * zoom;
rect.origin.y += y * zoom;
rect.size.width = rect.size.width * scale;
rect.size.height = rect.size.height * scale;
[UIView animateWithDuration:.5f animations:^{
self.videoPreView.transform = CGAffineTransformScale(transform, zoom, zoom);
self.videoPreView.frame = rect;
} completion:^(BOOL finished) {
}];
}
NSLog(@"放大%f",zoom);
}
- (AVCaptureConnection *)connectionWithMediaType:(NSString *)mediaType fromConnections:(NSArray *)connections
{
for ( AVCaptureConnection *connection in connections ) {
for ( AVCaptureInputPort *port in [connection inputPorts] ) {
if ( [[port mediaType] isEqual:mediaType] ) {
return connection;
}
}
}
return nil;
}
//#pragma mark 手势拉近/远 界面
//- (void)cameraInitOver{
// UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchDetected:)];
// pinch.delegate = self;
// [self.view addGestureRecognizer:pinch];
//}
//
//- (void)pinchDetected:(UIPinchGestureRecognizer*)recogniser
//{
// self.effectiveScale = self.beginGestureScale * recogniser.scale;
// if (self.effectiveScale < 1.0){
// self.effectiveScale = 1.0;
// }
// [self setVideoScale:self.effectiveScale pinch:YES];
//}
//
//- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
//{
// if ( [gestureRecognizer isKindOfClass:[UIPinchGestureRecognizer class]] ) {
// _beginGestureScale = _effectiveScale;
// }
// return YES;
//}
#pragma mark - 相机权限Alert
- (void)requestCameraPemissionWithResult:(void(^)( BOOL granted))completion
{
if ([AVCaptureDevice respondsToSelector:@selector(authorizationStatusForMediaType:)])
{
AVAuthorizationStatus permission =
[AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
switch (permission) {
case AVAuthorizationStatusAuthorized:
completion(YES);
break;
case AVAuthorizationStatusDenied:
case AVAuthorizationStatusRestricted:
completion(NO);
break;
case AVAuthorizationStatusNotDetermined:{
[AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo
completionHandler:^(BOOL granted) {
dispatch_async(dispatch_get_main_queue(), ^{
if (granted) {
completion(true);
} else {
completion(false);
}
});
}];
}
break;
}
}
}
- (void)showAlertToPromptCameraAuthorization {
UIAlertController *alertCtr = [UIAlertController alertControllerWithTitle:@"提示" message:@"您的相机功能没有打开，去“设置>拿趣用”设置一下吧" preferredStyle:UIAlertControllerStyleAlert];
[alertCtr addAction:[UIAlertAction actionWithTitle:@"关闭" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
dispatch_async(dispatch_get_main_queue(), ^(void){
[self leftBarButtonItemReturnAction];
});
}]];
[alertCtr addAction:[UIAlertAction actionWithTitle:@"去设置" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
dispatch_async(dispatch_get_main_queue(), ^(void){
[self.navigationController popToRootViewControllerAnimated:YES];
[Helper openURL:UIApplicationOpenSettingsURLString];
});
}]];
[self presentViewController:alertCtr animated:YES completion:nil];
}
-(void)addTwoAlertControllerAction:(NSString *)title message:(NSString *)message leftTitle:(NSString *)leftTitle rightTitle:(NSString *)rightTitle leftAction:(void (^)(UIAlertAction * _Nonnull action))leftAction rightAction:(void (^)(UIAlertAction * _Nonnull action))rightAction{
UIAlertController *alertCtr = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
[alertCtr addAction:[UIAlertAction actionWithTitle:leftTitle style:UIAlertActionStyleDefault handler:leftAction]];
[alertCtr addAction:[UIAlertAction actionWithTitle:rightTitle style:UIAlertActionStyleDefault handler:rightAction]];
[self presentViewController:alertCtr animated:YES completion:nil];
}
-(void)networkStatusAlert{
NetworkStatus internetStatus = [Helper internetStatus];
switch (internetStatus) {
case NotReachable:{
__weak typeof(self) weakSelf = self;
dispatch_async(dispatch_get_main_queue(), ^{
[weakSelf addTwoAlertControllerAction:@"提示" message:@"您的WLAN与蜂窝移动网功能没有打开，去“设置>拿趣用”设置一下吧" leftTitle:@"关闭" rightTitle:@"去设置" leftAction:^(UIAlertAction * _Nonnull action) {
} rightAction:^(UIAlertAction * _Nonnull action) {
[weakSelf.navigationController popToRootViewControllerAnimated:YES];
[Helper openURL:UIApplicationOpenSettingsURLString];
}];
});
}
break;
default:
break;
}
}
