[连接到Wifi Android Q

Question

我正在尝试使用以下代码连接到wifi

 val specifier = WifiNetworkSpecifier.Builder()
        .setSsid(machineID).build()

    val networkRequest = NetworkRequest.Builder()
        .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
        .setNetworkSpecifier(specifier)
        .build()

    val connectivityManager = context.applicationContext
        .getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager?

    connectivityManager?.requestNetwork(networkRequest,object:ConnectivityManager.NetworkCallback(){
        override fun onUnavailable() {
            callback.onWifiConnected(WifiConstant.WIFI_IP_ADDRESS_INVALID)
        }

        override fun onAvailable(network: Network) {
            val wifiInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI)

            if (wifiInfo.isConnected)
                callback.onWifiConnected("${getWifiManager()?.connectionInfo?.ipAddress!!}")
            else
                callback.onWifiConnected(WifiConstant.WIFI_IP_ADDRESS_INVALID)
        }
    })

但是我总是在此行中遇到运行时错误

val specifier = WifiNetworkSpecifier.Builder()

错误如下：

2019-09-25 13:49:00.718 28556-28556/com.aloha.asiaiot E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.aloha.asiaiot, PID: 28556
java.lang.NoClassDefFoundError: Failed resolution of: Landroid/net/wifi/WifiNetworkSpecifier$Builder;
    at com.aloha.asiaiot.common.util.wifi.WifiConnectionManager.connectToWifi(WifiConnectionManager.kt:77)
    at com.aloha.asiaiot.connectivity.devicescan.data.DeviceScanNetworkRepository.connectToWifi(DeviceScanNetworkRepository.kt:48)
    at com.aloha.asiaiot.connectivity.devicescan.domain.DeviceScanRepository.connectToWifi(DeviceScanRepository.kt:18)
    at com.aloha.asiaiot.connectivity.devicescan.domain.DeviceScanUseCase.connectToWifi(DeviceScanUseCase.kt:18)
    at com.aloha.asiaiot.connectivity.devicescan.presentation.viewmodel.DeviceScanViewModel.connectToWifi(DeviceScanViewModel.kt:41)
    at com.aloha.asiaiot.connectivity.devicescan.presentation.DeviceScanFragment.connectToGateway(DeviceScanFragment.kt:139)
    at com.aloha.asiaiot.connectivity.devicescan.presentation.DeviceScanFragment.access$connectToGateway(DeviceScanFragment.kt:29)
    at com.aloha.asiaiot.connectivity.devicescan.presentation.DeviceScanFragment$onActivityCreated$3.onClick(DeviceScanFragment.kt:72)
    at android.view.View.performClick(View.java:7339)
    at android.widget.TextView.performClick(TextView.java:14221)
    at android.view.View.performClickInternal(View.java:7305)
    at android.view.View.access$3200(View.java:846)
    at android.view.View$PerformClick.run(View.java:27787)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7058)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965)
 Caused by: java.lang.ClassNotFoundException: Didn't find class "android.net.wifi.WifiNetworkSpecifier$Builder" on path: DexPathList[[zip file "/data/app/com.aloha.asiaiot-k57tcS1ybEKsaCIu13TJnw==/base.apk"],nativeLibraryDirectories=[/data/app/com.aloha.asiaiot-k57tcS1ybEKsaCIu13TJnw==/lib/arm64, /system/lib64]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:134)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
    at com.aloha.asiaiot.common.util.wifi.WifiConnectionManager.connectToWifi(WifiConnectionManager.kt:77) 
    at com.aloha.asiaiot.connectivity.devicescan.data.DeviceScanNetworkRepository.connectToWifi(DeviceScanNetworkRepository.kt:48) 
    at com.aloha.asiaiot.connectivity.devicescan.domain.DeviceScanRepository.connectToWifi(DeviceScanRepository.kt:18) 
    at com.aloha.asiaiot.connectivity.devicescan.domain.DeviceScanUseCase.connectToWifi(DeviceScanUseCase.kt:18) 
    at com.aloha.asiaiot.connectivity.devicescan.presentation.viewmodel.DeviceScanViewModel.connectToWifi(DeviceScanViewModel.kt:41) 
    at com.aloha.asiaiot.connectivity.devicescan.presentation.DeviceScanFragment.connectToGateway(DeviceScanFragment.kt:139) 
    at com.aloha.asiaiot.connectivity.devicescan.presentation.DeviceScanFragment.access$connectToGateway(DeviceScanFragment.kt:29) 
    at com.aloha.asiaiot.connectivity.devicescan.presentation.DeviceScanFragment$onActivityCreated$3.onClick(DeviceScanFragment.kt:72) 
    at android.view.View.performClick(View.java:7339) 
    at android.widget.TextView.performClick(TextView.java:14221) 
    at android.view.View.performClickInternal(View.java:7305) 
    at android.view.View.access$3200(View.java:846) 
    at android.view.View$PerformClick.run(View.java:27787) 
    at android.os.Handler.handleCallback(Handler.java:873) 
    at android.os.Handler.dispatchMessage(Handler.java:99) 
    at android.os.Looper.loop(Looper.java:214) 
    at android.app.ActivityThread.main(ActivityThread.java:7058) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965) 

2019-09-25 13：49：00.747 28556-28556 / com.aloha.asiaiot

我也尝试使用下面的代码来解决较低的SDK：

 if (Build.VERSION.SDK_INT< Build.VERSION_CODES.Q) {
        val wifiConfiguration = WifiConfiguration()
    wifiConfiguration.SSID = String.format("\"%s\"", machineID)
    wifiConfiguration.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE)
    wifiConfiguration.status = WifiConfiguration.Status.ENABLED
    wifiConfiguration.priority = 40

    val wifiManager = getWifiManager()
    val netID = wifiManager?.addNetwork(wifiConfiguration)!!

    wifiManager.disconnect()
    wifiManager.enableNetwork(netID,true)
    wifiManager.reconnect()


    if (isWifiConnected(machineID))
        callback.onWifiConnected("${wifiManager.dhcpInfo.ipAddress}")
    else
        callback.onWifiConnected(WifiConstant.WIFI_IP_ADDRESS_INVALID)
    }

并且在我的isWifiConnected下面：

private fun isWifiConnected (machineID: String) : Boolean{
    if (getWifiManager()?.isWifiEnabled!!) {
        val wifiInfo = getWifiManager()?.connectionInfo
        if (wifiInfo?.ssid==machineID)
            return true
    }

    return false
}

但是在这一部分，我总是假的：

    wifiManager.disconnect()
    wifiManager.enableNetwork(netID,true)
    wifiManager.reconnect()

据文件说明：

此方法在API级别29中已弃用。a）有关触发与Wi-Fi网络的连接的新机制，请参见WifiNetworkSpecifier.Builder＃build（）。 b）有关新的API，请参见addNetworkSuggestions（java.util.List），removeNetworkSuggestions（java.util.List），以添加Wi-Fi网络，以便在自动连接到wifi时考虑。兼容性说明：对于面向Build.VERSION_CODES.Q或更高版本的应用程序，此API始终返回false。

我正在使用OS版本9在真实设备中进行测试，但是代码在模拟器中运行良好。请告知可能的原因。谢谢您的帮助。

Answer 1

该类已在Api级别29中添加，因此，如果您在android Pie上进行测试，它将无法正常工作。您需要包装检查构建版本的代码，并将其仅在android 10+上应用。