用系统自带的视听媒体的框架，AVFoundation实现照片拍摄。相比UIKit框架（UIImagePickerController高度封装），AVFoundation框架让开发者有更大的发挥空间。
首先看一下效果图：
下面贴上核心控制器代码：
#import "HWPhotoVC.h" #import <AVFoundation/AVFoundation.h> @interface HWPhotoVC () @property (nonatomic,strong) AVCaptureSession *captureSession;//负责输入和输出设备之间的数据传递 @property (nonatomic,strong) AVCaptureDeviceInput *captureDeviceInput;//负责从AVCaptureDevice获得输入数据 @property (nonatomic,strong) AVCaptureStillImageOutput *captureStillImageOutput;//照片输出流 @property (nonatomic,strong) AVCaptureVideoPreviewLayer *captureVideoPreviewLayer;//相机拍摄预览图层 @property (nonatomic,weak) UIView *containerView;//内容视图 @property (nonatomic,weak) UIImageView *focusCursor;//聚焦按钮 @property (nonatomic,weak) UIImageView *imgView;//拍摄照片 @end @implementation HWPhotoVC - (void)viewDidLoad { [super viewDidLoad]; self.navigationItem.title = @"拍照"; self.view.backgroundColor = [UIColor whiteColor]; //创建控件 [self creatControl]; } - (void)viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; //初始化信息 [self initPhotoInfo]; } - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; [self.captureSession startRunning]; } - (void)viewDidDisappear:(BOOL)animated { [super viewDidDisappear:animated]; [self.captureSession stopRunning]; } - (void)creatControl { CGFloat btnW = 150.f; CGFloat btnH = 40.f; CGFloat marginY = 20.f; CGFloat w = [UIScreen mainScreen].bounds.size.width; CGFloat h = [UIScreen mainScreen].bounds.size.height; //内容视图 CGFloat containerViewH = h - 64 - btnH - marginY * 3; UIView *containerView = [[UIView alloc] initWithFrame:CGRectMake(10,64 + marginY,w - 20,containerViewH)]; containerView.backgroundColor = [UIColor whiteColor]; containerView.layer.borderWidth = 1.f; containerView.layer.borderColor = [[UIColor grayColor] CGColor]; [self.view addSubview:containerView]; _containerView = containerView; //摄像头切换按钮 CGFloat cameraSwitchBtnW = 50.f; CGFloat cameraSwitchBtnMargin = 10.f; UIButton *cameraSwitchBtn = [[UIButton alloc] initWithFrame:CGRectMake(containerView.bounds.size.width - cameraSwitchBtnW - cameraSwitchBtnMargin,64 + marginY + cameraSwitchBtnMargin,cameraSwitchBtnW,cameraSwitchBtnW)]; [cameraSwitchBtn setImage:[UIImage imageNamed:@"camera_switch"] forState:UIControlStateNormal]; [cameraSwitchBtn addTarget:self action:@selector(cameraSwitchBtnOnClick) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:cameraSwitchBtn]; //聚焦图片 UIImageView *focusCursor = [[UIImageView alloc] initWithFrame:CGRectMake(50,50,75,75)]; focusCursor.alpha = 0; focusCursor.image = [UIImage imageNamed:@"camera_focus_red"]; [containerView addSubview:focusCursor]; _focusCursor = focusCursor; //拍摄照片容器 UIImageView *imgView = [[UIImageView alloc] initWithFrame:containerView.frame]; imgView.hidden = YES; imgView.layer.borderWidth = 1.f; imgView.layer.borderColor = [[UIColor grayColor] CGColor]; imgView.contentMode = UIViewContentModeScaleAspectFill; imgView.clipsToBounds = YES; [self.view addSubview:imgView]; _imgView = imgView; //按钮 NSArray *titleArray = @[@"拍摄照片",@"重新拍摄"]; CGFloat btnY = CGRectGetMaxY(containerView.frame) + marginY; CGFloat margin = (w - btnW * titleArray.count) / (titleArray.count + 1); for (int i = 0; i < titleArray.count; i++) { CGFloat btnX = margin + (margin + btnW) * i; UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(btnX,btnY,btnW,btnH)]; btn.tag = 1000 + i; [btn setTitle:titleArray[i] forState:UIControlStateNormal]; btn.backgroundColor = [UIColor orangeColor]; btn.layer.cornerRadius = 2.0f; btn.layer.masksToBounds = YES; if (i == 1) { btn.hidden = YES; } [btn addTarget:self action:@selector(btnOnClick:) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:btn]; } } - (void)initPhotoInfo { //初始化会话 _captureSession = [[AVCaptureSession alloc] init]; //设置分辨率 if ([_captureSession canSetSessionPreset:AVCaptureSessionPreset1280x720]) { _captureSession.sessionPreset = AVCaptureSessionPreset1280x720; } //获得输入设备,取得后置摄像头 AVCaptureDevice *captureDevice = [self getCameraDeviceWithPosition:AVCaptureDevicePositionBack]; if (!captureDevice) { NSLog(@"取得后置摄像头时出现问题"); return; } NSError *error = nil; //根据输入设备初始化设备输入对象，用于获得输入数据 _captureDeviceInput = [[AVCaptureDeviceInput alloc]initWithDevice:captureDevice error:&error]; if (error) { NSLog(@"取得设备输入对象时出错，错误原因：%@",error.localizedDescription); return; } //初始化设备输出对象，用于获得输出数据 _captureStillImageOutput = [[AVCaptureStillImageOutput alloc] init]; NSDictionary *outputSettings = @{AVVideoCodecKey:AVVideoCodecJPEG}; //输出设置 [_captureStillImageOutput setOutputSettings:outputSettings]; //将设备输入添加到会话中 if ([_captureSession canAddInput:_captureDeviceInput]) { [_captureSession addInput:_captureDeviceInput]; } //将设备输出添加到会话中 if ([_captureSession canAddOutput:_captureStillImageOutput]) { [_captureSession addOutput:_captureStillImageOutput]; } //创建视频预览层，用于实时展示摄像头状态 _captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.captureSession]; //摄像头方向 AVCaptureConnection *captureConnection = [self.captureVideoPreviewLayer connection]; captureConnection.videoOrientation = AVCaptureVideoOrientationPortrait; CALayer *layer = _containerView.layer; layer.masksToBounds = YES; _captureVideoPreviewLayer.frame = layer.bounds; //填充模式 _captureVideoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill; //将视频预览层添加到界面中 [layer insertSublayer:_captureVideoPreviewLayer below:self.focusCursor.layer]; [self addNotificationToCaptureDevice:captureDevice]; [self addGenstureRecognizer]; } - (void)btnOnClick:(UIButton *)btn { if (btn.tag == 1000) { //拍摄照片 [self photoBtnOnClick]; }else if (btn.tag == 1001) { //重新拍摄 [self resetPhoto]; } } #pragma mark 拍照 - (void)photoBtnOnClick { //根据设备输出获得连接 AVCaptureConnection *captureConnection = [self.captureStillImageOutput connectionWithMediaType:AVMediaTypeVideo]; captureConnection.videoOrientation = AVCaptureVideoOrientationPortrait; //根据连接取得设备输出的数据 [self.captureStillImageOutput captureStillImageAsynchronouslyFromConnection:captureConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer,NSError *error) { if (imageDataSampleBuffer) { NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer]; UIImage *image = [UIImage imageWithData:imageData]; _imgView.image = image; _imgView.hidden = NO; } }]; UIButton *btn = (UIButton *)[self.view viewWithTag:1001]; btn.hidden = NO; } //重新拍摄 - (void)resetPhoto { _imgView.hidden = YES; UIButton *btn = (UIButton *)[self.view viewWithTag:1001]; btn.hidden = YES; } #pragma mark - 通知 //给输入设备添加通知 - (void)addNotificationToCaptureDevice:(AVCaptureDevice *)captureDevice { //注意添加区域改变捕获通知必须首先设置设备允许捕获 [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) { captureDevice.subjectAreaChangeMonitoringEnabled = YES; }]; //捕获区域发生改变 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(areaChange:) name:AVCaptureDeviceSubjectAreaDidChangeNotification object:captureDevice]; } - (void)removeNotificationFromCaptureDevice:(AVCaptureDevice *)captureDevice { [[NSNotificationCenter defaultCenter] removeObserver:self name:AVCaptureDeviceSubjectAreaDidChangeNotification object:captureDevice]; } //移除所有通知 - (void)removeNotification { [[NSNotificationCenter defaultCenter] removeObserver:self]; } //设备连接成功 - (void)deviceConnected:(NSNotification *)notification { NSLog(@"设备已连接..."); } //设备连接断开 - (void)deviceDisconnected:(NSNotification *)notification { NSLog(@"设备已断开."); } //捕获区域改变 - (void)areaChange:(NSNotification *)notification { NSLog(@"捕获区域改变..."); } #pragma mark - 私有方法 //取得指定位置的摄像头 - (AVCaptureDevice *)getCameraDeviceWithPosition:(AVCaptureDevicePosition )position { NSArray *cameras = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]; for (AVCaptureDevice *camera in cameras) { if ([camera position] == position) { return camera; } } return nil; } #pragma mark 切换前后摄像头 - (void)cameraSwitchBtnOnClick { AVCaptureDevice *currentDevice = [self.captureDeviceInput device]; AVCaptureDevicePosition currentPosition = [currentDevice position]; [self removeNotificationFromCaptureDevice:currentDevice]; AVCaptureDevice *tochangeDevice; AVCaptureDevicePosition tochangePosition = AVCaptureDevicePositionFront; if (currentPosition == AVCaptureDevicePositionUnspecified || currentPosition == AVCaptureDevicePositionFront) { tochangePosition = AVCaptureDevicePositionBack; } tochangeDevice = [self getCameraDeviceWithPosition:tochangePosition]; [self addNotificationToCaptureDevice:tochangeDevice]; //获得要调整的设备输入对象 AVCaptureDeviceInput *tochangeDeviceInput = [[AVCaptureDeviceInput alloc] initWithDevice:tochangeDevice error:nil]; //改变会话的配置前一定要先开启配置，配置完成后提交配置改变 [self.captureSession beginConfiguration]; //移除原有输入对象 [self.captureSession removeInput:self.captureDeviceInput]; //添加新的输入对象 if ([self.captureSession canAddInput:tochangeDeviceInput]) { [self.captureSession addInput:tochangeDeviceInput]; self.captureDeviceInput = tochangeDeviceInput; } //提交会话配置 [self.captureSession commitConfiguration]; } //改变设备属性的统一操作方法 - (void)changeDeviceProperty:(void (^)(AVCaptureDevice *))propertyChange { AVCaptureDevice *captureDevice = [self.captureDeviceInput device]; NSError *error; //注意改变设备属性前一定要首先调用lockForConfiguration:调用完之后使用unlockForConfiguration方法解锁 if ([captureDevice lockForConfiguration:&error]) { propertyChange(captureDevice); [captureDevice unlockForConfiguration]; }else { NSLog(@"设置设备属性过程发生错误，错误信息：%@",error.localizedDescription); } } //设置闪光灯模式 - (void)setFlashMode:(AVCaptureFlashMode)flashMode { [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) { if ([captureDevice isFlashModeSupported:flashMode]) { [captureDevice setFlashMode:flashMode]; } }]; } //设置聚焦模式 - (void)setFocusMode:(AVCaptureFocusMode)focusMode { [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) { if ([captureDevice isFocusModeSupported:focusMode]) { [captureDevice setFocusMode:focusMode]; } }]; } //设置曝光模式 - (void)setExposureMode:(AVCaptureExposureMode)exposureMode { [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) { if ([captureDevice isExposureModeSupported:exposureMode]) { [captureDevice setExposureMode:exposureMode]; } }]; } //设置聚焦点 - (void)focusWithMode:(AVCaptureFocusMode)focusMode exposureMode:(AVCaptureExposureMode)exposureMode atPoint:(CGPoint)point { [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) { if ([captureDevice isFocusModeSupported:focusMode]) { [captureDevice setFocusMode:AVCaptureFocusModeAutoFocus]; } if ([captureDevice isFocusPointOfInterestSupported]) { [captureDevice setFocusPointOfInterest:point]; } if ([captureDevice isExposureModeSupported:exposureMode]) { [captureDevice setExposureMode:AVCaptureExposureModeAutoExpose]; } if ([captureDevice isExposurePointOfInterestSupported]) { [captureDevice setExposurePointOfInterest:point]; } }]; } //添加点按手势，点按时聚焦 - (void)addGenstureRecognizer { [self.containerView addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapScreen:)]]; } - (void)tapScreen:(UITapGestureRecognizer *)tapGesture { CGPoint point = [tapGesture locationInView:self.containerView]; //将UI坐标转化为摄像头坐标 CGPoint cameraPoint = [self.captureVideoPreviewLayer captureDevicePointOfInterestForPoint:point]; [self setFocusCursorWithPoint:point]; [self focusWithMode:AVCaptureFocusModeAutoFocus exposureMode:AVCaptureExposureModeAutoExpose atPoint:cameraPoint]; } //设置聚焦光标位置 - (void)setFocusCursorWithPoint:(CGPoint)point { self.focusCursor.center = point; self.focusCursor.transform = CGAffineTransformMakeScale(1.5,1.5); self.focusCursor.alpha = 1.0; [UIView animateWithDuration:1.0 animations:^{ self.focusCursor.transform = CGAffineTransformIdentity; } completion:^(BOOL finished) { self.focusCursor.alpha = 0; }]; } - (void)dealloc { [self removeNotification]; } @end
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原文链接：https://www.f2er.com/iOS/534480.html