...

app/src/main/java/com/base/browserwhite/ui/activity/scanqrc/ScanQRCActivity.kt

 package com.base.browserwhite.ui.activity.scanqrc
 
 import android.Manifest
+import android.content.pm.PackageManager
 import android.graphics.Color
+import android.hardware.camera2.CameraAccessException
+import android.hardware.camera2.CameraCharacteristics
+import android.hardware.camera2.CameraManager
 import androidx.activity.addCallback
 import androidx.camera.core.AspectRatio
 import androidx.camera.core.Camera
@@ -9,11 +13,13 @@ import androidx.camera.core.CameraSelector
 import androidx.camera.core.Preview
 import androidx.camera.lifecycle.ProcessCameraProvider
 import androidx.core.content.ContextCompat
+import androidx.core.view.isVisible
 import androidx.core.view.updatePadding
 import com.base.browserwhite.databinding.ActivityScanQrcBinding
 import com.base.browserwhite.ui.activity.BaseActivity
 import com.base.browserwhite.ui.views.DialogViews.showGerPermission
 import com.base.browserwhite.utils.BarUtils
+import com.base.browserwhite.utils.LogEx
 import com.base.browserwhite.utils.PermissionHelp.checkCameraPermission
 import java.util.concurrent.ExecutorService
 import java.util.concurrent.Executors
@@ -21,12 +27,16 @@ import kotlin.math.abs
 import kotlin.math.max
 import kotlin.math.min
 
+
 class ScanQRCActivity : BaseActivity<ActivityScanQrcBinding>() {
 
+    private val TAG = "ScanQRCActivity"
+
     override val binding: ActivityScanQrcBinding by lazy {
         ActivityScanQrcBinding.inflate(layoutInflater)
     }
 
+
     //相机
     private var camera: Camera? = null
     private var preview: Preview? = null
@@ -40,6 +50,12 @@ class ScanQRCActivity : BaseActivity<ActivityScanQrcBinding>() {
         BarUtils.setStatusBarColor(this, Color.TRANSPARENT)
         binding.root.updatePadding(top = BarUtils.getStatusBarHeight())
 
+        val hasFlash = this.packageManager.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)
+        binding.ivShoudian.isVisible = hasFlash
+        if (hasFlash) {
+            binding.ivShoudian.isSelected = false
+        }
+
         if (checkCameraPermission()) {
             initCamera()
         } else {
@@ -65,11 +81,24 @@ class ScanQRCActivity : BaseActivity<ActivityScanQrcBinding>() {
             onBackPressedDispatcher.onBackPressed()
         }
 
-        binding.ivShoudian.setOnClickListener { }
+        binding.ivShoudian.setOnClickListener {
+            try {
+                if (binding.ivShoudian.isSelected) {
+                    closeFlash()
+                } else {
+                    openFlash()
+                }
+            } catch (e: Exception) {
+                LogEx.logDebug(TAG, "flash $e")
+                return@setOnClickListener
+            }
+            binding.ivShoudian.isSelected = !binding.ivShoudian.isSelected
+        }
         binding.ivPhoto.setOnClickListener { }
     }
 
     private fun initCamera() {
+
         cameraExecutor = Executors.newSingleThreadExecutor()
 
         val cameraProviderFuture = ProcessCameraProvider.getInstance(this)
@@ -153,4 +182,33 @@ class ScanQRCActivity : BaseActivity<ActivityScanQrcBinding>() {
         private const val RATIO_4_3_VALUE = 4.0 / 3.0
         private const val RATIO_16_9_VALUE = 16.0 / 9.0
     }
+
+
+    private fun openFlash() {
+        val cameraManager = getSystemService(CAMERA_SERVICE) as CameraManager
+        cameraManager.setTorchMode(getBackCameraId(), true)
+    }
+
+    private fun closeFlash() {
+        val cameraManager = getSystemService(CAMERA_SERVICE) as CameraManager
+        cameraManager.setTorchMode(getBackCameraId(), false)
+    }
+
+    private fun getBackCameraId(): String {
+        var cameraId: String? = null
+        try {
+            val cameraManager = getSystemService(CAMERA_SERVICE) as CameraManager
+            for (id in cameraManager.cameraIdList) {
+                val characteristics: CameraCharacteristics = cameraManager.getCameraCharacteristics(id)
+                if (characteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_BACK) {
+                    cameraId = id
+                    break
+                }
+            }
+        } catch (e: CameraAccessException) {
+            e.printStackTrace()
+        }
+        return cameraId ?: ""
+    }
+
 }
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