android - Kotlin 上的 Android 手电筒

Question

您需要打开手机上的 LED。我写了一个简单的应用程序。应用程序启动时 LED 应亮起。该代码与 Stackoverflow 应用程序代码上的解决方案相匹配：

package com.example.flash

import android.hardware.Camera
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle

class MainActivity : AppCompatActivity() {

 override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     setContentView(R.layout.activity_main)
     var cam = Camera.open()
     var p = cam.parameters
     p.flashMode = Camera.Parameters.FLASH_MODE_TORCH
     cam.parameters = p
     cam.startPreview()
 }
} 

AndroidManifest.xml：

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.kgskassa">
       <uses-permission android:name="android.permission.INTERNET" />
       <uses-permission android:name="android.permission.CAMERA" />
       <uses-permission android:name="android.permission.FLASHLIGHT"/>
       <uses-feature android:name="android.hardware.camera" />
       <uses-feature android:name="android.hardware.camera.autofocus"/>

允许访问手机上的摄像头。不工作。想法？

标签： androidkotlinflashlight

Answer 1

package com.example.flash

import android.content.Context
import android.hardware.camera2.CameraAccessException
import android.hardware.camera2.CameraManager
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {
    var flashLightStatus: Boolean = false

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        openFlashLight()
    }

    private fun openFlashLight() {
        val cameraManager = getSystemService(Context.CAMERA_SERVICE) as CameraManager
        val cameraId = cameraManager.cameraIdList[0]
        if (!flashLightStatus) {
            try {
                cameraManager.setTorchMode(cameraId, true)
                flashLightStatus = true

            } catch (e: CameraAccessException) {
            }
        } else {
            try {
                cameraManager.setTorchMode(cameraId, false)
                flashLightStatus = false
            } catch (e: CameraAccessException) {
            }
        }

    }
}