ios - 如何知道相机闪光灯是否已经点亮（iOS）？

Question

更新：我知道如何打开/关闭相机闪光灯。我想知道的是相机闪光灯是否已经点亮。

我想知道 iPhone 上的相机闪光灯是否点亮，但我还没有找到任何UIImagePickerController允许我这样做的方法。我知道我们可以得到cameraFlashMode。但我想知道相机闪光灯是否已经点亮。

例如，如果模式是UIImagePickerControllerCameraFlashModeAuto，在我控制之前相机闪光灯是否点亮，我想在做一些操作之前知道相机闪光灯的状态。

Answer 1

令人惊讶的是，这真的没有回答第一个回答的人甚至没有回答这个问题......

   func torchButtonPressed() {
    //
    let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
    do {
        try device.lockForConfiguration()
    } catch {
        return
    }
    if device.torchMode == AVCaptureTorchMode.Off {
        do {
            device.torchMode = AVCaptureTorchMode.On
            try device.setTorchModeOnWithLevel(AVCaptureMaxAvailableTorchLevel)
        } catch {
            print("no torch")
            return
        }

    } else {
        device.torchMode = AVCaptureTorchMode.Off
    }
    device.unlockForConfiguration()
}

Answer 2

您可以使用以下代码找到

#import <AVFoundation/AVFoundation.h>


- (void) turnTorchOn: (bool) on {

Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice");
if (captureDeviceClass != nil) {
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([device hasTorch] && [device hasFlash]){

    [device lockForConfiguration:nil];
    if (on) {
        NSLog(@"Torch is ON");
    } else {
      NSLog(@"Torch is OFF");

    }
    [device unlockForConfiguration];
}
}
}

快乐编码...!!!

Answer 3

我遇到了和你一样的问题。

iOS 支持两种模式 - 闪光灯和手电筒。下面的代码检查每个是否可用，然后根据您调用的代码打开或关闭它们。它还检查灯是否已经打开/关闭。

闪光灯开 -

-(void)flashOn {
Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice");
if (captureDeviceClass != nil) {
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    [device lockForConfiguration:nil];

    if ([device hasFlash]) {
        if ([device flashMode] == AVCaptureFlashModeOff) {
            [device setFlashMode:AVCaptureFlashModeOn];
        }
    }

    if ([device hasTorch]) {
        if ([device torchMode] == AVCaptureTorchModeOff) {
            [device setTorchMode:AVCaptureTorchModeOn];
        }
    }

    [device unlockForConfiguration];
  }
}

闪光灯关闭-

-(void)flashOff {
Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice");
if (captureDeviceClass != nil) {
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    [device lockForConfiguration:nil];

    if ([device hasFlash]) {
        if ([device flashMode] == AVCaptureFlashModeOn) {
            [device setFlashMode:AVCaptureFlashModeOff];
        }
    }

    if ([device hasTorch]) {
        if ([device torchMode] == AVCaptureTorchModeOn) {
            [device setTorchMode:AVCaptureTorchModeOff];
        }
    }

    [device unlockForConfiguration];
  }

}