java代码
packagecom.sdt.app;/* 手机编程王APP & AIDE编译器联合出品 官方微信2133688724 微信公众号：手机编程APP 官网：www.shoujibiancheng.com */importandroid.Manifest;importandroid.content.pm.PackageManager;importandroid.hardware.camera2.CameraAccessException;importandroid.hardware.camera2.CameraManager;importandroid.os.Build;importandroid.os.Bundle;importandroid.view.View;importandroid.widget.Button;importandroidx.appcompat.app.AppCompatActivity;importandroidx.core.app.ActivityCompat;publicclassMainActivityextendsAppCompatActivity{privateButtonbtnToggle;privatebooleanisFlashOn=false;privateCameraManagercameraManager;privateStringcameraId;@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);btnToggle=findViewById(R.id.btnToggle);// 初始化相机管理器（安卓5.0+ API）cameraManager=(CameraManager)getSystemService(CAMERA_SERVICE);try{// 获取后置摄像头ID（通常是闪光灯所在位置）cameraId=cameraManager.getCameraIdList()[0];}catch(CameraAccessExceptione){e.printStackTrace();}// 按钮点击事件btnToggle.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.M){// 动态申请相机权限（安卓6.0+必须）if(ActivityCompat.checkSelfPermission(MainActivity.this,Manifest.permission.CAMERA)!=PackageManager.PERMISSION_GRANTED){ActivityCompat.requestPermissions(MainActivity.this,newString[]{Manifest.permission.CAMERA},101);return;}toggleFlash();}}});}// 开关闪光灯核心方法privatevoidtoggleFlash(){try{if(isFlashOn){// 关闭闪光灯cameraManager.setTorchMode(cameraId,false);btnToggle.setText("打开手电筒");isFlashOn=false;}else{// 打开闪光灯cameraManager.setTorchMode(cameraId,true);btnToggle.setText("关闭手电筒");isFlashOn=true;}}catch(CameraAccessExceptione){e.printStackTrace();}}// 权限申请回调@OverridepublicvoidonRequestPermissionsResult(intrequestCode,String[]permissions,int[]grantResults){super.onRequestPermissionsResult(requestCode,permissions,grantResults);if(requestCode==101){if(grantResults.length>0&&grantResults[0]==PackageManager.PERMISSION_GRANTED){toggleFlash();}}}// 退出时关闭闪光灯@OverrideprotectedvoidonDestroy(){super.onDestroy();if(isFlashOn){try{cameraManager.setTorchMode(cameraId,false);}catch(CameraAccessExceptione){e.printStackTrace();}}}}activity_main.xml代码<?xml version="1.0"encoding="utf-8"?><LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:gravity="center"android:orientation="vertical"><Buttonandroid:id="@+id/btnToggle"android:layout_width="200dp"android:layout_height="80dp"android:text="打开手电筒"android:textSize="20sp"/></LinearLayout>AndroidManifest.xml代码<?xml version="1.0"encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"package="com.sdt.app"android:versionCode="1"android:versionName="1.0"><uses-sdk android:minSdkVersion="29"android:targetSdkVersion="31"/><uses-permission android:name="android.permission.CAMERA"/><uses-permission android:name="android.permission.FLASHLIGHT"/><uses-feature android:name="android.hardware.camera.flash"android:required="true"/><application android:allowBackup="true"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"android:roundIcon="@mipmap/ic_launcher_round"android:supportsRtl="true"android:theme="@style/Theme.MyApplication"><activity android:name=".MainActivity"android:exported="true"><intent-filter><action android:name="android.intent.action.MAIN"/><category android:name="android.intent.category.LAUNCHER"/></intent-filter></activity></application></manifest>
