像本機相機應用程序一樣執行閃光（燈光）

Question

我如何像本機相機應用一樣執行閃光？ 我發現以下代碼可以打開燈，但是我需要拍攝快照。

if(self.videoDevice.hasTorch) {
    [self.videoDevice lockForConfiguration:nil];
    [self.videoDevice setTorchModeOnWithLevel: 1.0 error: nil];
    [self.videoDevice unlockForConfiguration];
}

Answer 1

試試這個。 似乎與您期望的一樣

http://iosdevelopertips.com/camera/flashlight-application-using-the-iphone-led.html

Answer 2

您必須將TorchLevel設置在0.0到1.0之間，然后在非常小的間隔內再次設置為0.0。

- (BOOL)setTorchModeOnWithLevel:(float)torchLevel error:(NSError **)outError

Answer 3

試試這個代碼：

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

        if ([device hasTorch])
        {
            [device lockForConfiguration:nil];
            [device setTorchMode:AVCaptureTorchModeOn];
            [device unlockForConfiguration];
        }       
    }
}

Answer 4

它接縫那里沒有閃光燈功能，所以執行閃光燈的（唯一的？）可能性是使用計時器。

    - (IBAction)doFlash:(id)sender {
        if(self.videoDevice.hasTorch) {
            flashCounter = 0;
            [NSTimer scheduledTimerWithTimeInterval: 0.1
                                             target:self
                                           selector:@selector(flashLightTicker:)
                                           userInfo:nil
                                            repeats: YES];
        }
    }

    - (void)flashLightTicker:(id)sender {
        [self.videoDevice lockForConfiguration:nil];
        if(flashCounter == 0) {
            [self.videoDevice setTorchModeOnWithLevel: 0.1 error: nil];
        }
        if(flashCounter == 5) {
            [self.videoDevice setTorchMode: AVCaptureTorchModeOff];
        }
        if(flashCounter == 7) {
            [self.videoDevice setTorchModeOnWithLevel: AVCaptureMaxAvailableTorchLevel error: nil];
        }
        if(flashCounter >= 10) {
            [self.videoDevice setTorchMode: AVCaptureTorchModeOff];
            [sender invalidate];
        }
        [self.videoDevice unlockForConfiguration];
        flashCounter++;
    }