如何在Swift 4中设置设备的闪存模式？

Question

我正在调用一个函数来尝试打开我设备的闪存:

private func flashOn(device:AVCaptureDevice)
{
    print("flashOn called");
    do {

        try device.lockForConfiguration()
        // line below returns warning 'flashMode' was deprecated in iOS 10.0: Use AVCapturePhotoSettings.flashMode instead.
        device.flashMode = AVCaptureDevice.FlashMode.auto
        device.unlockForConfiguration()

    } catch {

        // handle error
        print("flash on error");
    }

}

设置device.flashMode到AVCaptureDevice.FlashMode.auto带来了警告,"'flashMode’在iOS的10.0已被否决:使用AVCapturePhotoSettings.flashMode代替." 虽然它只是一个警告,但它在测试我的应用时不会启用闪存,因此我将该行更改为:

device.flashMode = AVCaptureDevice.FlashMode.auto

所以我设置了这一行,就像它暗示:

AVCapturePhotoSettings.flashMode = AVCaptureDevice.FlashMode.auto

我得到错误"实例成员'flashMode'不能用于类型'AVCapturePhotoSettings'"

所以我不知道如何使用Swift 4.0在Xcode版本9中设置闪存.我在Stack Overflow中找到的所有答案都是针对以前的版本.

Answer 1

我一直面临着同样的问题.不幸的是,许多有用的方法在iOS10和11中被弃用了.以下是我设法解决它的方法:

AVCapturePhotoSettings对象是唯一的,无法重复使用,因此每次使用此方法时都需要获取新设置:

/// the current flash mode
private var flashMode: AVCaptureDevice.FlashMode = .auto

/// Get settings
///
/// - Parameters:
///   - camera: the camera
///   - flashMode: the current flash mode
/// - Returns: AVCapturePhotoSettings
private func getSettings(camera: AVCaptureDevice, flashMode: AVCaptureDevice.FlashMode) -> AVCapturePhotoSettings {
    let settings = AVCapturePhotoSettings()

    if camera.hasFlash {
        settings.flashMode = flashMode
    }
    return settings
}

如您所见,不需要lockConfiguration.

CurrentFlashMode是枚举,它是为了保持清晰而创建的:

 @IBAction func captureButtonPressed(_ sender: UIButton) {
    let settings = getSettings(camera: camera, flashMode: flashMode)
    photoOutput.capturePhoto(with: settings, delegate: self)
}

然后在拍摄照片时使用它:

/// the current flash mode
private var flashMode: AVCaptureDevice.FlashMode = .auto

/// Get settings
///
/// - Parameters:
///   - camera: the camera
///   - flashMode: the current flash mode
/// - Returns: AVCapturePhotoSettings
private func getSettings(camera: AVCaptureDevice, flashMode: AVCaptureDevice.FlashMode) -> AVCapturePhotoSettings {
    let settings = AVCapturePhotoSettings()

    if camera.hasFlash {
        settings.flashMode = flashMode
    }
    return settings
}

希望它会有所帮助.

Answer 2

对于目标C：

    - (IBAction)turnTorchOn: (UIButton *) sender {
    sender.selected = !sender.selected;
    BOOL on;
    if (sender.selected) {
        on = true;
    }
    else{
        on = false ;
    }
    // check if flashlight available
    Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice");
    if (captureDeviceClass != nil) {
        AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        AVCapturePhotoSettings *photosettings = [AVCapturePhotoSettings photoSettings];
        if ([device hasTorch] && [device hasFlash]){

            [device lockForConfiguration:nil];
            if (on) {
                [device setTorchMode:AVCaptureTorchModeOn];
                photosettings.flashMode = AVCaptureFlashModeOn;
                //torchIsOn = YES; //define as a variable/property if you need to know status
            } else {
                [device setTorchMode:AVCaptureTorchModeOff];
                 photosettings.flashMode = AVCaptureFlashModeOn;
                //torchIsOn = NO;
            }
            [device unlockForConfiguration];
        }
    }
 }