Question

在我的应用程序中，我可以选择手电筒灯。然而，只有iPhone 4和iPhone 4S有火炬灯。其他设备没有手电筒灯。如何找到当前的设备型号？请帮我。提前谢谢。

Answer 1

您不应将设备型号用作是否存在功能的指示器。相反，请使用API来准确告诉您该功能是否存在。

在您的情况下，您希望使用AVCaptureDevice的{{1}}属性：

-hasTorch

AV Foundation Programming Guide和AVCaptureDevice Class Reference

提供了更多信息

Answer 2

与上面的代码相比，您可以拥有更少的代码并使用更少的内存：

NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
BOOL hasTorch = NO;

for (AVCaptureDevice *device in devices) {
    if ([device hasTorch]) {
        hasTorch = YES;
        break;
    }
}

hasTorch现在将包含正确的值

Answer 3

此代码可让您的设备开启手电筒。但它也会检测手电筒是打开还是关闭，反之亦然。

- (void)torchOnOff: (BOOL) onOff {

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([device hasTorch]) {
    [device lockForConfiguration:nil];
    if (device.torchMode == AVCaptureTorchModeOff) {
        device.torchMode = AVCaptureTorchModeOn;
        NSLog(@"Torch mode is on.");
    } else {
        device.torchMode = AVCaptureTorchModeOff;
        NSLog(@"Torch mode is off.");
    }
    [device unlockForConfiguration];
}

}

Answer 4

Swift 4

if let device = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo) {
    if (device.hasTorch) {
        // Device has torch
    } else {
        // Device does not have torch
    }
} else {
    // Device does not support video type (and so, no torch)
}

Answer 5

devicesWithMediaType:现已弃用。

斯威夫特4：

let discoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: .video, position: .back)

for device in discoverySession.devices {
    if device.hasTorch {
        return true
    }
}

return false

Answer 6

雨燕4

func deviceHasTorch() -> Bool {
    return AVCaptureDevice.default(for: AVMediaType.video)?.hasTorch == true
}

如何确定我的iOS设备是否有手电筒？

6 个答案: