AVCaptureDevice對flash light的操作

//改變FlashLightStatus -(void)changeFlashLightStatus{ // check if flashlight available AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; if ([device hasTorch] && [device hasFlash]){ [device lockForConfiguration:nil]; if (device.torchMode == AVCaptureTorchModeOff) { [device setTorchMode:AVCaptureTorchModeOn]; [device setFlashMode:AVCaptureFlashModeOn]; //torchIsOn = YES; //define as a variable/property if you need to know status } else { [device setTorchMode:AVCaptureTorchModeOff]; [device setFlashMode:AVCaptureFlashModeOff]; //torchIsOn = NO; } [device unlockForConfiguration]; } } 以下轉自http://www.helmsmansoft.com/index.php/archives/1525 在appstore的眾多的軟件之中，相信很多人都用過一款軟件 “手電筒” , 在iPhone中，利用設備上的閃光燈來開發手電筒功能，下面就說下具體的實現方法： 開啟閃光燈的API封裝在框架AVFoundation.framework中，所以要想實現此功能，首先就要在程序中加入此框架，然後引入頭 #import 先來看下這個框架內的一些內容： AVCaptureDevice.h主要用來獲取iphone一些關於相機設備的屬性。 前置和後置攝像頭 enum { AVCaptureDevicePositionBack = 1, AVCaptureDevicePositionFront = 2 }; typedef NSInteger AVCaptureDevicePosition; 閃光燈開關 enum { AVCaptureFlashModeOff = 0, AVCaptureFlashModeOn = 1, AVCaptureFlashModeAuto = 2 }; typedef NSInteger AVCaptureFlashMode; 手電筒開關 enum { AVCaptureTorchModeOff = 0, AVCaptureTorchModeOn = 1, AVCaptureTorchModeAuto = 2, }; typedef NSInteger AVCaptureTorchMode; 焦距調整 enum { AVCaptureFocusModeLocked = 0, AVCaptureFocusModeAutoFocus = 1, AVCaptureFocusModeContinuousAutoFocus = 2, }; typedef NSInteger AVCaptureFocusMode; 曝光量調節 enum { AVCaptureExposureModeLocked = 0, AVCaptureExposureModeAutoExpose = 1, AVCaptureExposureModeContinuousAutoExposure = 2, }; typedef NSInteger AVCaptureExposureMode; 白平衡 enum { AVCaptureWhiteBalanceModeLocked = 0, AVCaptureWhiteBalanceModeAutoWhiteBalance = 1, AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance = 2, }; typedef NSInteger AVCaptureWhiteBalanceMode; 下面實現一個最簡單的手電筒功能： - (void)viewDidLoad { [super viewDidLoad]; UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect]; btn.frame = CGRectMake(100, 100, 100, 40); btn.backgroundColor = [UIColor clearColor]; [btn setTitle:@"打開手電筒" forState:UIControlStateNormal]; [btn addTarget:self action:@selector(flashMode:) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:btn]; // Do any additional setup after loading the view, typically from a nib. } - (void)flashMode:(id)sender { AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; //This method returns the default device of the given media type currently available on the system. UIButton *btn = (UIButton *)sender; if([device hasTorch]){ //如果設備有手電筒功能 if (device.torchMode == AVCaptureTorchModeOff) //如果手電筒關閉 { [btn setTitle:@"關閉手電筒" forState:UIControlStateNormal]; [device lockForConfiguration:nil]; //鎖定配置 [device setTorchMode:AVCaptureTorchModeOn]; //開啟手電筒 [device unlockForConfiguration]; //解鎖 }else{ [btn setTitle:@"打開手電筒" forState:UIControlStateNormal]; [device lockForConfiguration:nil]; [device setTorchMode:AVCaptureTorchModeOff]; [device unlockForConfiguration]; } }else{ UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示信息" message:@"您的設備不支持此功能" delegate:nil cancelButtonTitle:@"確定" otherButtonTitles: nil]; [alert show]; [alert release]; } } 其他Media Type的聲明 NSString *const AVMediaTypeVideo; NSString *const AVMediaTypeAudio; NSString *const AVMediaTypeText; NSString *const AVMediaTypeClosedCaption; NSString *const AVMediaTypeSubtitle; NSString *const AVMediaTypeTimecode; NSString *const AVMediaTypeTimedMetadata; NSString *const AVMediaTypeMuxed; 若是要檢測裝置是否提供該功能，可以透過 - (BOOL)hasMediaType:(NSString *)mediaType 來取得 取得攝像頭後，我們可以透過 @property(nonatomic, readonly) BOOL hasTorch @property(nonatomic, readonly) BOOL hasFlash 來判斷該攝像頭是否有提供閃光燈 我是要持續開啟所以使用Torch Mode lockForConfiguration跟unlockForConfiguration是配對的API 呼叫lockForConfiguration就可以控制硬件了 控制完畢後要呼叫unlockForConfiguration [device setTorchMode: AVCaptureTorchModeOn]; [device setTorchMode: AVCaptureTorchModeOff]; 這兩行代碼，就是開關閃光燈的代碼 注意此代碼要在真機下作用