1.比较常用，也比较简单，因此粘贴到这里
2.调用了AVCaptureSession对象的beginConfiguration方法后,勿忘调用commitConfiguration方法,有始有终.
3.1 在程序①返回时②失去焦点时③扫描成功时千万不要忘记关闭闪光灯,并关闭 session 对象,否则极易崩溃.
1 - (void)onFlash{ 2 3 AVCaptureDevice *avDevice = self.device; 4 if (![avDevice hasFlash] || ![avDevice hasTorch]) { 5 UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"" message:@"打开闪光灯失败！请检测您的闪光灯！" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles: nil, nil]; 6 [alert show]; 7 return; 8 } 9 10 [self openFlashLight]; 11 } 12 13 - (void)openFlashLight 14 { 15 UIButton *sender = self.buttonFlash; 16 sender.selected = !sender.selected; 17 if (sender.selected) { 18 [self openFlash]; 19 } else{ 20 [self shutdownFlash]; 21 } 22 } 23 24 - (void)openFlash{ 25 26 AVCaptureDevice *avDevice = self.device; 27 AVCaptureSession *avSession = self.captureSession; 28 if (avDevice.torchMode == AVCaptureTorchModeOff) { 29 [avSession beginConfiguration]; 30 [avDevice lockForConfiguration:nil]; 31 [avDevice setTorchMode:AVCaptureTorchModeOn]; 32 [avDevice setFlashMode:AVCaptureFlashModeOn]; 33 [avDevice unlockForConfiguration]; 34 [avSession commitConfiguration]; 35 self.buttonFlash.selected = YES; 36 } 37 } 38 39 - (void)shutdownFlash{ 40 41 AVCaptureDevice *avDevice = self.device; 42 AVCaptureSession *avSession = self.captureSession; 43 if (avDevice.torchMode == AVCaptureTorchModeOn) { 44 [avSession beginConfiguration]; 45 [avDevice lockForConfiguration:nil]; 46 [avDevice setTorchMode:AVCaptureTorchModeOff]; 47 [avDevice setFlashMode:AVCaptureFlashModeOff]; 48 [avDevice unlockForConfiguration]; 49 [avSession commitConfiguration]; 50 self.buttonFlash.selected = NO; 51 } 52 }
3.2以下是退出时的处理代码,不能丢!
1 - (void)endScan{ 2 [self stopAnimation]; 3 [self shutdownFlash]; 4 [self stopSeesion]; 5 } 6 7 - (void)stopAnimation{ 8 [self.imageViewShockWave.layer removeAllAnimations]; 9 } 10 11 - (void)shutdownFlash{ 12 13 AVCaptureDevice *avDevice = self.device; 14 AVCaptureSession *avSession = self.captureSession; 15 if (avDevice.torchMode == AVCaptureTorchModeOn) { 16 [avSession beginConfiguration]; 17 [avDevice lockForConfiguration:nil]; 18 [avDevice setTorchMode:AVCaptureTorchModeOff]; 19 [avDevice setFlashMode:AVCaptureFlashModeOff]; 20 [avDevice unlockForConfiguration]; 21 [avSession commitConfiguration]; 22 self.buttonFlash.selected = NO; 23 } 24 } 25 26 - (void)stopSeesion{ 27 if (_captureSession) { 28 [_captureSession stopRunning]; 29 } 30 }