网上的方法大部分只支持 6.0 以下的手机，于是写了个兼容 6.0 以上手机的工具类：
class FlashUtils {
companion object {
fun get():FlashUtils = Holder.instance
}
private object Holder {
val instance = FlashUtils()
}
private var isFlashOn = false
fun toggle(context: Context) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
val camManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
val cameraId = camManager.cameraIdList[0]
camManager.setTorchMode(cameraId, !isFlashOn)
isFlashOn = !isFlashOn
} else {
var camera = Camera.open()
var parameters = camera.parameters
if (isFlashOn) {
parameters.flashMode = Camera.Parameters.FLASH_MODE_OFF
} else {
parameters.flashMode = Camera.Parameters.FLASH_MODE_TORCH
}
isFlashOn = !isFlashOn
camera.parameters = parameters
}
}
}
需要 2 个权限：
<uses-permission android:name="android.permission.CAMERA"></uses-permission>
<uses-permission android:name="android.permission.FLASHLIGHT" />
