Android Webrtc之Kurento-one2one-call webrtc对等连接ClientA注册,ClientB注册.ClientA创建SdpOffer,成功后调用setLocalDescription()设置为本地描述.ClientA发起Call，将SdpOffer发送给信令服务器.ClientB接收到请求(incomingCall),ClientB接受后配置本地媒体数据.ClientB创建SdpOffer,成功后调用setLocalDescription()设置为本地描述.ClientB发起incomingCallResponse，将sdpOffer发送给信令服务器.ClientB接收到startCommunication,调用setRemoteDescription将SdpAnswer设置为远程描述,ClientB已经获知连接双方的配置.ClientA接收到callResponse,调用setRemoteDescription将SdpAnswer设置为远程描述,ClientA已经获知连接双方的配置.信令主要流程图引入库 implementation 'org.webrtc:google-webrtc:1.0.32006' implementation 'org.java-websocket:Java-WebSocket:1.5.3' implementation "com.google.code.gson:gson:2.+"初始化PeerConnectionFactoryPeerConnectionFactory.initialize( PeerConnectionFactory.InitializationOptions.builder( this.applicationContext ) .setFieldTrials("WebRTC-H264HighProfile/Enabled/") .setEnableInternalTracer(true) .createInitializationOptions() )创建PeerConnecitonFactoryval encoderFactory = DefaultVideoEncoderFactory(bglBase.eglBaseContext, true, true) val decoderFactory = DefaultVideoDecoderFactory(bglBase.eglBaseContext) peerConnectionFactory = PeerConnectionFactory.builder() .setVideoEncoderFactory(encoderFactory) .setVideoDecoderFactory(decoderFactory) .createPeerConnectionFactory()创建PeerConnection val peerConnectionFactory = createPeerConnectionFactory() // 配置STUN穿透服务器 转发服务器 val iceServers = ArrayList<PeerConnection.IceServer>() val iceServer: PeerConnection.IceServer = PeerConnection.IceServer.builder(Config.STUN).createIceServer() iceServers.add(iceServer) // streamList = ArrayList() val configuration = PeerConnection.RTCConfiguration(iceServers) peerConnection = peerConnectionFactory.createPeerConnection(configuration, this) }在Observer.onIceCandidate响应时，将信息发送给服务端override fun onIceCandidate(iceCandidate: IceCandidate?) { //发送IceCandidate sendIceCandidate(iceCandidate) }在OnMessage接收到iceCandidate添加到peerConnectionpeerConnection.addIceCandidate(iceCandidate)初始化WebSocketClientval webSocketClient=object :WebSocketClient(URI.create(Config.URL)){ override fun onOpen(handshakedata: ServerHandshake?) { Log.i(TAG, "WebSocket连接成功") } override fun onMessage(message: String?) { Log.e( TAG, "######## onMessage ########\n$message" ) val jsonObject = Gson().fromJson(message, JsonObject::class.java) when (jsonObject["id"].asString) { REGISTER_RESPONSE -> { // 注册回应 } INCOMING_CALL -> { //来电 } CALL_RESPONSE -> { //呼叫回应 } START_COMMUNICATION -> { //开始通迅 } STOP_COMMUNICATION->{ //停止通迅 } ICE_CANDIDATE -> { //接收到IceCandidate后调用addIceCandidate } } } override fun onClose(code: Int, reason: String?, remote: Boolean) { Log.i(TAG, "onClose code=$code reason=$reason remote=$remote") } override fun onError(ex: Exception?) { ex?.printStackTrace() } }通过PeerConnectionFactory创建数据源VideoTrack/AudioTrack准备摄像头，是否有前置摄像头，如果有就用前置摄像头：private fun createCameraCapturer(enumerator: CameraEnumerator): VideoCapturer? { val deviceNames = enumerator.deviceNames // First, try to find front facing camera Log.d(TAG, "Looking for front facing cameras.") for (deviceName in deviceNames) { if (enumerator.isFrontFacing(deviceName)) { Logging.d(TAG, "Creating front facing camera capturer.") val videoCapturer: VideoCapturer? = enumerator.createCapturer(deviceName, null) if (videoCapturer != null) { return videoCapturer } } } // Front facing camera not found, try something else Log.d(TAG, "Looking for other cameras.") for (deviceName in deviceNames) { if (!enumerator.isFrontFacing(deviceName)) { Logging.d(TAG, "Creating other camera capturer.") val videoCapturer: VideoCapturer? = enumerator.createCapturer(deviceName, null) if (videoCapturer != null) { return videoCapturer } } } return null }在Android系统下有两种Camera，一种称为 Camera1，是一种比较老的采集视频数据的方式，别一种称为Camera2，是一种新的采集视频的方法。它们之间的最大区别是Camera1使用同步方式调用API，Camera2使用异步方式,所以Camera2更高效。这里如果支持Camera2就使用Camera2, 如果不支持就使用Camera1。 private fun createVideoCapturer(): VideoCapturer { return if (Camera2Enumerator.isSupported(this)) { createCameraCapturer(Camera2Enumerator(this))!! } else { createCameraCapturer(Camera1Enumerator(true))!! } }配置视频数据源VideoTrack val videoSource = peerConnectionFactory.createVideoSource(true) val surfaceTextureHelper = SurfaceTextureHelper.create( Thread.currentThread().name, eglBase().eglBaseContext ) val videoCapturer: VideoCapturer = createVideoCapturer() //将videoCapturer与videoSource绑定在一起 videoCapturer.initialize( surfaceTextureHelper, this.applicationContext, videoSource.capturerObserver ) //调用startCapture打开摄像头 videoCapturer.startCapture( Config.VIDEO_RESOLUTION_WIDTH, Config.VIDEO_RESOLUTION_HEIGHT, Config.VIDEO_FPS ) val videoTrack = peerConnectionFactory.createVideoTrack(Config.VIDEO_TRACK_ID, videoSource) videoTrack.setEnabled(true) videoTrack.addSink(localSurfaceView) 配置音频数据源AudioTrack val audioConstraints = MediaConstraints() //回声消除 audioConstraints.mandatory.add( MediaConstraints.KeyValuePair( "googEchoCancellation", "true" ) ) //自动增益 audioConstraints.mandatory.add(MediaConstraints.KeyValuePair("googAutoGainControl", "true")) //高音过滤 audioConstraints.mandatory.add(MediaConstraints.KeyValuePair("googHighpassFilter", "true")) //噪音处理 audioConstraints.mandatory.add( MediaConstraints.KeyValuePair( "googNoiseSuppression", "true" ) ) val audioSource = peerConnectionFactory.createAudioSource(audioConstraints) val audioTrack = peerConnectionFactory.createAudioTrack(Config.AUDIO_TRACK_ID, audioSource) 添加音视频到MediaStreamval medisStream = peerConnectionFactory.createLocalMediaStream("local_stream") medisStream.addTrack(audioTrack) medisStream.addTrack(videoTrack)同样在onAddTrack添加远程视频流即可，以下是两个手机的测试：

搭建Kurento服务 在Centos7上搭建Kurento官方网址：https://github.com/Kurento/kurento-media-server官网教程：https://doc-kurento.readthedocs.io/en/latest/user/installation.htmlKurento是一个WebRTC媒体服务器，同时提供了一系列的客户端API，可以简化供浏览器、移动平台使用的视频类应用程序的开发。Kurento支持:群组通信（group communications）媒体流的转码（transcoding）、录制（recording）、广播（broadcasting）、路由（routing）高级媒体处理特性，包括：机器视觉（CV）、视频索引、增强现实（AR）、语音分析Kurento的模块化架构使其与第三方媒体处理算法 —— 语音识别、人脸识别 —— 很容易集成。和大部分多媒体通信技术一样，Kurento应用的整体架构包含两个层（layer）或者叫平面（plane）信号平面（Signaling Plane）：负责通信的管理，例如媒体协商、QoS、呼叫建立、身份验证等媒体平面（Media Plane）：负责媒体传输、编解码等WebRTC让浏览器能够进行实时的点对点通信（在没有服务器的情况下）。但是要想实现群组通信、媒体流录制、媒体广播、转码等高级特性，没有媒体服务器是很难实现的。Kurento的核心是一个媒体服务器（Kurento Media Server，KMS），负责媒体的传输、处理、加载、录制，主要基于 GStreamer实现。此媒体服务器的特性包括:网络流协议处理，包括HTTP、RTP、WebRTC支持媒体混合（mixing）、路由和分发的群组通信（MCU、SFU功能）对机器视觉和增强现实过滤器的一般性支持媒体存储支持，支持对WebM、MP4进行录像操作，可以播放任何GStreamer支持的视频格式对于GStreamer支持的编码格式，可以进行任意的转码，例如VP8, H.264, H.263, AMR, OPUS, Speex, G.711安装coturnGithub：https://github.com/coturn/coturnyum install -y openssl-devel libevent-devel git #clone 源码 git clone https://github.com/coturn/coturn.git cd coturn ./configure make sudo make install # 启动turnserver nohup turnserver -L 0.0.0.0 -a -u kurento:kurento -v -f -r psvmc.cn & #然后查看相应的端口号3478是否存在进程 sudo lsof -i:3478这样就说明已经可以启动了，接下来我们先停掉turnserver，重新配置turnserver 默认加载配置文件/usr/local/etc/turnserver.conf.cp /usr/local/etc/turnserver.conf.default /usr/local/etc/turnserver.conf #生成证书 openssl req -x509 -newkey rsa:2048 -keyout /usr/local/etc/turn_server_pkey.pem -out /usr/local/etc/turn_server_cert.pem -days 99999 -nodes修改turnserver.conf:vi /usr/local/etc/turnserver.conf内容:# 设置转发的ip（局域网ip），如果不设置，他会自己选择默认的 relay-ip=****** # 转发的外网ip(本机外网ip)，用于NAT 地址映射 external-ip=****** # 转发的线程数，其实默认不设置最好 relay-threads=5 #UDP 最小端口和最大端口 min-port=40000 max-port=60000 # WebRTC 的消息里会用到 fingerprint # WebRTC 认证需要 lt-cred-mech #中继服务器的监听器IP地址 listening-ip=0.0.0.0 #静态账号 user=kurento:kurento # 统计状态信息的redis db # redis-statsdb="ip=xx.xx.xxx.xx dbname=3 password=xxxx port=6379 connect_timeout=30" # 用户登录域(例如:dev.com) realm=**** # 证书 cert=/usr/local/etc/turn_server_cert.pem pkey=/usr/local/etc/turn_server_pkey.pem # 输出log log-file=stdout mobility重新启动turnserver:nohup turnserver -c /usr/local/etc/turnserver.conf -v | ts '[%Y-%m-%d %H:%M:%S]' >> /usr/local/etc/turn.log 2>&1 &注意：这个ts命令，是openssl的一个指令，用来打印日期yum install moreutils man ts echo -e "hello world" | ts '[%Y-%m-%d %H:%M:%S]'打开服务器端口：firewall-cmd --zone=public --add-port=3478/tcp --permanent firewall-cmd --zone=public --add-port=3478/udp --permanent firewall-cmd --reload测试stunhttps://webrtc.github.io/samples/src/content/peerconnection/trickle-ice/remove掉默认的stunstun:stun.l.google.com:19302测试stun不需要账号密码,添加上stun:YOUR__IP:3478，然后点击Gather candidates只要出现Done即为成功，下面提示的fail不用在意测试turn添加turn:YOUR__IP:3478,username/password填配置文件里的kurento/kurento同样只要出现Done即为成功用docker安装kurentodocker pull kurento/kurento-media-server:latest运行docker run -d --name kms -p:8888:8888/tcp kurento/kurento-media-server:latest查看一下docker ps -aede4f883c11d kurento/kurento-media-server:latest “/entrypoint.sh” 5 seconds ago Up 4 seconds (health: starting) 0.0.0.0:8888->8888/tcp进入Dockersudo docker exec -it 704d3ed68a49 bash测试服务是否正常curl \ --include \ --header "Connection: Upgrade" \ --header "Upgrade: websocket" \ --header "Host: 127.0.0.1:8888" \ --header "Origin: 127.0.0.1" \ http://127.0.0.1:8888/kurento正常启动会显示{card-describe title="提示"}HTTP/1.1 500 Internal Server ErrorServer: WebSocket++/0.7.0{/card-describe}退出容器exit该Kurento媒体服务器的端口（KMS）过程中默认监听8888客户端WebSocket连接ws://YOUR_IP:8888/kurento配置kurento服务器进入kurento的镜像编辑kurento的配置文件：#进入镜像 docker exec -it kms /bin/bash #安装vim apt-get update apt-get install vim #进入配置文件夹 cd /etc/kurento/modules/kurento/ #编辑配置文件 vim WebRtcEndpoint.conf.ini修改stun和turn信息stunServerAddress=YOUR_IP stunServerPort=3478 turnURL=kurento:kurento@YOUR_IP:3478?transport=udp退出容器，重启kurentoexit docker restart kms测试git clone https://gitee.com/psvmc/kurento-tutorial-java.git cd kurento-tutorial-java/kurento-hello-world vi src/main/resources/static/js/index.js在函数function uiStart()里，增加一个叫iceservers的变量，格式如下:let iceservers={ "iceServers":[ { urls:"stun:YOUR_IP:3478" }, { urls:["turn:YOUR_IP:3478"], username:"kurento", credential: "kurento" } ] }修改option:const options = { localVideo: uiLocalVideo, remoteVideo: uiRemoteVideo, mediaConstraints: { audio: true, video: true }, onicecandidate: (candidate) => sendMessage({ id: 'ADD_ICE_CANDIDATE', candidate: candidate, }), configuration: iceservers //这里增加了一个configuration的key };启动项目mvn -U clean spring-boot:run -Dkms.url=ws://your_ip:8888/kurento启动完之后用浏览器打开demo页面https://your_ip:8443/

Android传感器说明 名称说明TYPE_ACCELEROMETER加速度传感器TYPE_MAGNETIC_FIELD磁场传感器TYPE_GYROSCOPE陀螺仪传感器TYPE_LIGHT光照传感器TYPE_PRESSURE气压传感器TYPE_TEMPERATURE手机内部温度传感器TYPE_PROXIMITY距离传感器TYPE_GRAVITY重力传感器TYPE_LINEAR_ACCELERATION线性加速度传感器TYPE_ROTATION_VECTOR旋转矢量传感器TYPE_RELATIVE_HUMIDITY湿度传感器TYPE_AMBIENT_TEMPERATURE手机外部温度传感器TYPE_STEP_DETECTOR累计步数传感器TYPE_STEP_COUNTER单次步数传感器TYPE_ORIENTATION方向传感器检查传感器服务//获取传感器服务 sensorManager = getSystemService(Context.SENSOR_SERVICE) as SensorManager //获取当前手机支持的感应器并打印 sensorManager.getSensorList(Sensor.TYPE_ALL).forEach { Log.e(TGA, "Sensor:${it.name} ${it.stringType}") }

Jetpack Compose 底部导航栏 注意：您需要有Android Studio Arctic Fox 及更高版本才能在您的项目中使用Jetpack Compose。添加库转到您的项目级gradle.build文件，并添加以下扩展名：buildscript { ext { compose_version = '1.0.2' } // ... }现在转到应用级gradle.build文件，并添加以下内容：android { // ... kotlinOptions { jvmTarget = '1.8' useIR = true } buildFeatures { // ... compose true } composeOptions { kotlinCompilerExtensionVersion compose_version } } dependencies { // ... implementation "androidx.compose.ui:ui:$compose_version" implementation "androidx.compose.material:material:$compose_version" implementation "androidx.compose.ui:ui-tooling:$compose_version" implementation "androidx.navigation:navigation-compose:2.4.0-alpha08" implementation "androidx.activity:activity-compose:1.3.1" // ... }创建顶部栏打开activity（例如MainActivity.kt），并在类之外添加以下可组合函数以创建topbar@Composable fun TopBar() { TopAppBar( title = { Text(text = stringResource(R.string.app_name), fontSize = 18.sp) }, backgroundColor = colorResource(id = R.color.colorPrimary), contentColor = Color.White ) } @Preview(showBackground = true) @Composable fun TopBarPreview() { TopBar() }创建底部导航栏在创建底部导航栏之前，我们必须准备Item；创建一个Sealed Class并指定NavigationItem作为名称。并使用参数为每个条形项目创建一个模型：route：必须是unique。用来从底部导航栏导航到视图icon : 栏项的图标title : 栏项的名称sealed class NavigationItem(var route: String, var icon: Int, var title: String) { object Home : NavigationItem("home", R.mipmap.ic_home, "首页") object Recommend : NavigationItem("recommend", R.mipmap.ic_recommend, "关注") object Books : NavigationItem("books", R.mipmap.ic_book, "书城") object Profile : NavigationItem("profile", R.mipmap.ic_profile, "我的") }同样，在MainActivity.kt 中，添加以下可组合函数：@Composable fun BottomNavigationBar() { val items = listOf( NavigationItem.Home, NavigationItem.Recommend, NavigationItem.Books, NavigationItem.Profile ) BottomNavigation( backgroundColor = colorResource(id = R.color.colorPrimary), contentColor = Color.White ) { items.forEach { item -> BottomNavigationItem( icon = { Icon(painterResource(id = item.icon), contentDescription = item.title) }, label = { Text(text = item.title) }, selectedContentColor = Color.White, unselectedContentColor = Color.White.copy(0.4f), alwaysShowLabel = true, selected = false, onClick = { /* Add code later */ } ) } } } @Preview(showBackground = true) @Composable fun BottomNavigationBarPreview() { BottomNavigationBar() }创建包含顶部栏和底部导航栏的视图这里我将使用Scaffold，创建一个名为MainScreen()的新组合函数，里面有一个Scaffold布局，并添加我们之前创建的TopBar()和BottomNavigationBar()class MainActivity : ComponentActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContent { MainScreen() } } } @Composable fun MainScreen() { Scaffold( topBar = { TopBar() }, bottomBar = { BottomNavigationBar() } ) { /* Add code later */ } } @Preview(showBackground = true) @Composable fun MainScreenPreview() { MainScreen() }将导航栏与视图连接起来（导航）连接之前，需要先创建Views,我创建了4个名为*Screen的 Kotlin 文件HomeScreen.kt@Composable fun HomeScreen() { Column( modifier = Modifier .fillMaxSize() .background(colorResource(id = R.color.colorPrimaryDark)) .wrapContentSize(Alignment.Center) ) { Text( text = "Home View", fontWeight = FontWeight.Bold, color = Color.White, modifier = Modifier.align(Alignment.CenterHorizontally), textAlign = TextAlign.Center, fontSize = 25.sp ) } } @Preview(showBackground = true) @Composable fun HomeScreenPreview() { HomeScreen() }RecommendScreen.kt@Composable fun RecommendScreen() { Column( modifier = Modifier .fillMaxSize() .background(colorResource(id = R.color.colorPrimaryDark)) .wrapContentSize(Alignment.Center) ) { Text( text = "Recommend View", fontWeight = FontWeight.Bold, color = Color.White, modifier = Modifier.align(Alignment.CenterHorizontally), textAlign = TextAlign.Center, fontSize = 25.sp ) } } @Preview(showBackground = true) @Composable fun RecommendScreenPreview() { RecommendScreen() }BooksScreen.kt@Composable fun BooksScreen() { Column( modifier = Modifier .fillMaxSize() .background(colorResource(id = R.color.colorPrimaryDark)) .wrapContentSize(Alignment.Center) ) { Text( text = "Books View", fontWeight = FontWeight.Bold, color = Color.White, modifier = Modifier.align(Alignment.CenterHorizontally), textAlign = TextAlign.Center, fontSize = 25.sp ) } } @Preview(showBackground = true) @Composable fun BooksScreenPreview() { BooksScreen() }ProfileScreen.kt@Composable fun ProfileScreen() { Column( modifier = Modifier .fillMaxSize() .background(colorResource(id = R.color.colorPrimaryDark)) .wrapContentSize(Alignment.Center) ) { Text( text = "Profile View", fontWeight = FontWeight.Bold, color = Color.White, modifier = Modifier.align(Alignment.CenterHorizontally), textAlign = TextAlign.Center, fontSize = 25.sp ) } } @Preview(showBackground = true) @Composable fun ProfileScreenPreview() { ProfileScreen() }接下来在BottomNavigationBar中，添加参数navController，并创建navBackStackEntry和currentRoute。使用currentRoute，我们检查是否必须突出显示栏项目，然后使用navigate()方法导航到视图@Composable fun BottomNavigationBar(navController: NavController) { val items = listOf( NavigationItem.Home, NavigationItem.Recommend, NavigationItem.Books, NavigationItem.Profile ) BottomNavigation( backgroundColor = colorResource(id = R.color.colorPrimary), contentColor = Color.White ) { val navBackStackEntry by navController.currentBackStackEntryAsState() val currentRoute = navBackStackEntry?.destination?.route items.forEach { item -> BottomNavigationItem( icon = { Icon(painterResource(id = item.icon), contentDescription = item.title) }, label = { Text(text = item.title) }, selectedContentColor = Color.White, unselectedContentColor = Color.White.copy(0.4f), alwaysShowLabel = true, selected = currentRoute == item.route, onClick = { navController.navigate(item.route) { navController.graph.startDestinationRoute?.let { route -> popUpTo(route) { saveState = true } } launchSingleTop = true // 重新选择同一项目时避免同一目的地的多个副本 restoreState = true } } ) } } } @Preview(showBackground = true) @Composable fun BottomNavigationBarPreview() { // BottomNavigationBar() }创建一个新的可组合函数并将其命名为Navigation()，参数为NavHostController类型的参数navController。在这里，我们创建了一个NavHost，我们将Home视图设置为startDestination，我们将每个View的路由设置为可组合的。@Composable fun Navigation(navController: NavHostController) { NavHost(navController, startDestination = NavigationItem.Home.route) { composable(NavigationItem.Home.route) { HomeScreen() } composable(NavigationItem.Recommend.route) { RecommendScreen() } composable(NavigationItem.Books.route) { BooksScreen() } composable(NavigationItem.Profile.route) { ProfileScreen() } } }在MainScreen()中创建NavigationController，并将其传递给BottomNavigationBar和Navigation@Composable fun MainScreen() { val navController = rememberNavController() Scaffold( topBar = { TopBar() }, bottomBar = { BottomNavigationBar(navController) } ) { Navigation(navController) } }

adb shell input keyevent 通过adb shell input keyevent，event_code发送到设备usage: input [text|keyevent] input text <string> input keyevent <event_code>event_code:0 --> "KEYCODE_UNKNOWN" 1 --> "KEYCODE_MENU" 2 --> "KEYCODE_SOFT_RIGHT" 3 --> "KEYCODE_HOME" 4 --> "KEYCODE_BACK" 5 --> "KEYCODE_CALL" 6 --> "KEYCODE_ENDCALL" 7 --> "KEYCODE_0" 8 --> "KEYCODE_1" 9 --> "KEYCODE_2" 10 --> "KEYCODE_3" 11 --> "KEYCODE_4" 12 --> "KEYCODE_5" 13 --> "KEYCODE_6" 14 --> "KEYCODE_7" 15 --> "KEYCODE_8" 16 --> "KEYCODE_9" 17 --> "KEYCODE_STAR" 18 --> "KEYCODE_POUND" 19 --> "KEYCODE_DPAD_UP" 20 --> "KEYCODE_DPAD_DOWN" 21 --> "KEYCODE_DPAD_LEFT" 22 --> "KEYCODE_DPAD_RIGHT" 23 --> "KEYCODE_DPAD_CENTER" 24 --> "KEYCODE_VOLUME_UP" 25 --> "KEYCODE_VOLUME_DOWN" 26 --> "KEYCODE_POWER" 27 --> "KEYCODE_CAMERA" 28 --> "KEYCODE_CLEAR" 29 --> "KEYCODE_A" 30 --> "KEYCODE_B" 31 --> "KEYCODE_C" 32 --> "KEYCODE_D" 33 --> "KEYCODE_E" 34 --> "KEYCODE_F" 35 --> "KEYCODE_G" 36 --> "KEYCODE_H" 37 --> "KEYCODE_I" 38 --> "KEYCODE_J" 39 --> "KEYCODE_K" 40 --> "KEYCODE_L" 41 --> "KEYCODE_M" 42 --> "KEYCODE_N" 43 --> "KEYCODE_O" 44 --> "KEYCODE_P" 45 --> "KEYCODE_Q" 46 --> "KEYCODE_R" 47 --> "KEYCODE_S" 48 --> "KEYCODE_T" 49 --> "KEYCODE_U" 50 --> "KEYCODE_V" 51 --> "KEYCODE_W" 52 --> "KEYCODE_X" 53 --> "KEYCODE_Y" 54 --> "KEYCODE_Z" 55 --> "KEYCODE_COMMA" 56 --> "KEYCODE_PERIOD" 57 --> "KEYCODE_ALT_LEFT" 58 --> "KEYCODE_ALT_RIGHT" 59 --> "KEYCODE_SHIFT_LEFT" 60 --> "KEYCODE_SHIFT_RIGHT" 61 --> "KEYCODE_TAB" 62 --> "KEYCODE_SPACE" 63 --> "KEYCODE_SYM" 64 --> "KEYCODE_EXPLORER" 65 --> "KEYCODE_ENVELOPE" 66 --> "KEYCODE_ENTER" 67 --> "KEYCODE_DEL" 68 --> "KEYCODE_GRAVE" 69 --> "KEYCODE_MINUS" 70 --> "KEYCODE_EQUALS" 71 --> "KEYCODE_LEFT_BRACKET" 72 --> "KEYCODE_RIGHT_BRACKET" 73 --> "KEYCODE_BACKSLASH" 74 --> "KEYCODE_SEMICOLON" 75 --> "KEYCODE_APOSTROPHE" 76 --> "KEYCODE_SLASH" 77 --> "KEYCODE_AT" 78 --> "KEYCODE_NUM" 79 --> "KEYCODE_HEADSETHOOK" 80 --> "KEYCODE_FOCUS" 81 --> "KEYCODE_PLUS" 82 --> "KEYCODE_MENU" 83 --> "KEYCODE_NOTIFICATION" 84 --> "KEYCODE_SEARCH" 85 --> "TAG_LAST_KEYCODE"

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kotlin-android-extensions 已被弃用，如何使用 @Parcelize？ 第 1 步。更新到最新的 kotlin 版本 -1.4.20并替换apply plugin: 'kotlin-android-extensions'toapply plugin: 'kotlin-parcelize'或者plugins { .. id 'kotlin-parcelize' }第 2 步。从 android {} 中删除以下代码androidExtensions { experimental = true }第 3 步。最后，替换旧的 import ->import kotlinx.android.parcel.Parcelizetoimport kotlinx.parcelize.Parcelize新插件：https : //plugins.gradle.org/plugin/org.jetbrains.kotlin.plugin.parcelize

迁移已弃用的 Kotlin Android Extension 使用ViewBinding 最近出现在了一个这样的警告：The 'kotlin-android-extensions' Gradle plugin is deprecated. Please use this migration guide (https://goo.gle/kotlin-android-extensions-deprecation) to start working with View Binding (https://developer.android.com/topic/libraries/view-binding) and the 'kotlin-parcelize' plugin.kotlinx.android.synthetic 不再是推荐的做法,删除支持显式findViewById，用ViewBinding替代ViewBinding与 Kotlin Extensions相比，它增加了视图查找和类型安全的编译时检查。但视图绑定后，可让您更轻松地编写与视图交互的代码。启用视图绑定后，它会为该模块中存在的每个 XML 布局文件生成一个绑定类。如何启用视图ViewBinding？在build.gradle中添加：android { .. buildFeatures { viewBinding true } }如何使用ViewBinding？如果为模块启用了视图绑定，则会为模块包含的每个 XML 布局文件生成一个绑定类。每个绑定类都包含对根视图和所有具有 ID 的视图的引用。绑定类的名称是通过将 XML 文件的名称转换为 Pascal 大小写并Binding在末尾添加单词来生成的。在Activity中使用ViewBindingprivate lateinit var binding: ActivityMainBinding override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) binding = ActivityMainBinding.inflate(layoutInflater) setContentView(binding.root) }使用binding对象访问Viewbinding.name.text = "this is ViewBinding"在Fragment中使用ViewBinding在Fragment中使用ViewBinding需要注意，因为ViewBinding不能很好地与Fragment一起使用，如果不在OnDestroy清除，则它不会从内存中清除，导致内存泄漏。private var _binding: FragmentMainBinding? = null private val binding get() = _binding!! override fun onCreateView( inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle? ): View? { _binding = FragmentMainBinding.inflate(inflater, container, false) return binding.root } override fun onDestroyView() { super.onDestroyView() _binding = null }像在activity中一样使用对象访问视图binding.name.text = "this is ViewBinding"备注ViewBinding将为模块中的每个XML布局生成一个绑定对象，例如：activity_main.xml<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout>ViewBinding将生成 ActivityMainBinding.javapublic final class ActivityMainBinding implements ViewBinding { @NonNull private final ConstraintLayout rootView; @NonNull public final TextView textView; ... }ViewBinding将为每个具有指定id. 在ActivityMainBinding.java中，ViewBinding生成一个公共inflate方法。它调用bind将绑定属性的位置，并进行一些错误检查。

Room数据库Schema export Error 在使用Android Room数据库的时候报错了：Schema export directory is not provided to the annotation processor so we cannot export the schema. You can either provide `room.schemaLocation` annotation processor argument OR set exportSchema to false.如果您不需要检查架构并且想要摆脱警告，只需将exportSchema = false添加到RoomDatabase中，如下所示:@Database(entities = { YourEntity.class }, version = 1, exportSchema = false) public abstract class AppDatabase extends RoomDatabase { //... }另一种方法是在应用模块的build.gradle文件中，将此文件添加到defaultConfig部分(在android部分下面)。这会将架构写到项目文件夹的schemas子文件夹中。android { // ... (compileSdkVersion, buildToolsVersion, etc) defaultConfig { // ... (applicationId, miSdkVersion, etc) kapt { arguments { arg("room.schemaLocation","$projectDir/schemas".toString()) } } } buildTypes { // ... (buildTypes, compileOptions, etc) } } //...以上是Kotlin,如果是Java：android { // ... (compileSdkVersion, buildToolsVersion, etc) defaultConfig { // ... (applicationId, miSdkVersion, etc) javaCompileOptions { annotationProcessorOptions { arguments = ["room.schemaLocation":"$projectDir/schemas".toString()] } } } // ... (buildTypes, compileOptions, etc) }当执行项目后，在Android Studio 的Project视图下，查看项目，会发现Module生成了一个schemas的文件夹，打开.json文件看起来像这样：{ "formatVersion": 1, "database": { "version": 1, "identityHash":"6240057b6178b803a0bf9915edf969e3", "entities": [ { "tableName":"sms_table", "createSql":"CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `message` TEXT, `date` INTEGER, `client_id` INTEGER)", "fields": [ { "fieldPath":"id", "columnName":"id", "affinity":"INTEGER" }, { "fieldPath":"message", "columnName":"message", "affinity":"TEXT" }, { "fieldPath":"date", "columnName":"date", "affinity":"INTEGER" }, { "fieldPath":"clientId", "columnName":"client_id", "affinity":"INTEGER" } ], "primaryKey": { "columnNames": [ "id" ], "autoGenerate": true }, "indices": [], "foreignKeys": [] } ], "setupQueries": [ "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)", "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, "6240057b6178b803a0bf9915edf969e3")" ] } }

Android改变状态栏文本颜色(WHITE/BLACK) API> = 23从API v23及更高版本开始，可以将以下内容添加到AppTheme styles.xml中：解决方案1// View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR: 将状态栏的文字设置为黑色 window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR解决方案1<item name="android:statusBarColor">@color/colorPrimaryDark</item> <item name="android:windowLightStatusBar">true</item>当android:windowLightStatusBar设置为true，状态栏文字颜色将能够可以看出，当状态栏的颜色是白色的，而当android:windowLightStatusBar设置为false，状态栏文字颜色将被设计在状态栏的颜色是可以看到暗。API <23在Android中无法更改状态栏的颜色。可以在应用程序中设置状态栏的背景色val window: Window = activity.getWindow() // clear FLAG_TRANSLUCENT_STATUS flag: window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS) // add FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS flag to the window window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS) // finally change the color window.setStatusBarColor(ContextCompat.getColor(activity,R.color.my_statusbar_color))https://developer.android.google.cn/reference/android/view/Window.html#setStatusBarColor(int)