如何在iPhone应用程序中使用手电筒？

Question

我需要在我的应用中使用iPhone Flash灯.但是,当用户打开闪光灯时,相机不会拍照.我怎样才能做到这一点？在这里,我附上了我的代码.但是,当我打开闪光灯时,相机会拍照.

AVCaptureDeviceInput *flashInput = [AVCaptureDeviceInput deviceInputWithDevice:device error: nil];
            AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];

            AVCaptureSession *session = [[AVCaptureSession alloc] init];

            [session beginConfiguration];
            [device lockForConfiguration:nil];

            [device setTorchMode:AVCaptureTorchModeOn];
            [device setFlashMode:AVCaptureFlashModeOn];

            [session addInput:flashInput];
            [session addOutput:output];

            [device unlockForConfiguration];

            [output release];

            [session commitConfiguration];
            [session startRunning];

            [self setTorchSession:session];

我在编码时错在哪里？请帮我.提前致谢.

Answer 1

我的应用程序中有一个火炬按钮,它使用以下3种方法.

- (void)initialiseTorch {

    if (!session) {
        AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        session = [[AVCaptureSession alloc] init];
        AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error: nil];
        [session addInput:input];
        AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];
        [session addOutput:output];
        [session startRunning];
        [output release];
    }
}

- (void)releaseTorch {  
    if (session) {
        [session stopRunning];
        [session release];
        session = nil;
    }
}

- (void) lightButtonPressed {    

    if (!session) {
        [self initialiseTorch];
    }

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    [session beginConfiguration];
    [device lockForConfiguration:nil];
    if ([device torchMode] == AVCaptureTorchModeOn) {
        [device setTorchMode:AVCaptureTorchModeOff];
    } else {
        [device setTorchMode:AVCaptureTorchModeOn];
    }
    [device unlockForConfiguration];
    [session commitConfiguration];
}

我可以在代码之间看到的唯一区别是您还设置了Flash模式.我还配置了我的会话,然后在单独的beginConfiguration传递中打开/关闭手电筒