有没有办法在录制开始时让闪光灯一直亮着？(iOS +世博会/世博会-相机)

#import <AVFoundation/AVFoundation.h>

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([device hasTorch] && [device isTorchModeSupported:AVCaptureTorchModeOn]) {
    // 设备支持闪光灯功能
}

NSError *error = nil;
if ([device lockForConfiguration:&error]) {
    [device setTorchMode:AVCaptureTorchModeOn];
    [device unlockForConfiguration];
} else {
    NSLog(@"闪光灯打开失败：%@", error.localizedDescription);
}

if ([device lockForConfiguration:&error]) {
    [device setTorchMode:AVCaptureTorchModeOff];
    [device unlockForConfiguration];
} else {
    NSLog(@"闪光灯关闭失败：%@", error.localizedDescription);
}