Android开发 USB开发

版权声明

本文来自博客园，作者：观心静 ，转载请注明原文链接：https://www.cnblogs.com/guanxinjing/p/16258670.html

本文版权归作者和博客园共有，欢迎转载，但必须给出原文链接，并保留此段声明，否则保留追究法律责任的权利。

前言

 　　此博客讲解Usb插入的设备信息获取与注意事项

注意事项

Usb设备的插拔会导致Activity重建，这是正常的。Android在外接一些设备后默认认为页面的状态是需要更新的，比如操作方式，多屏状态等等。我们可以在AndroidManifest.xml设置我们希望重建与不希望重建的配置。如下：

        <activity
            android:name=".ui.aging.autoaging.AutoAgingActivity"
            android:exported="false"
            android:configChanges="keyboard|keyboardHidden">
        </activity>

configChanges这个属性控制着,我们activity在某些情况下是不需要重新创建activity的,这里的不重新创建意味着activity的生命周期将保持不变,不会重新走任何一个生命周期包括onResume.这里设置方向keyboard和尺寸keyboardHidden,就会让插拔Usb键盘鼠标的时候部重建Activity

USB线

    private fun initUsbReceiver() {
        val filter = IntentFilter()
        filter.addAction("android.hardware.usb.action.USB_STATE")
        mUsbBroadcastReceiver = object : BroadcastReceiver() {
            override fun onReceive(context: Context, intent: Intent) {
                val action = intent.action
                if (action == "android.hardware.usb.action.USB_STATE") {
                    val connected = intent.extras.getBoolean("connected")
                    if (connected) {
                        Toast.makeText(this@UsbActivity, "USB已连接", Toast.LENGTH_SHORT).show()
                    } else {
                        Toast.makeText(this@UsbActivity, "USB已断开", Toast.LENGTH_SHORT).show()
                    }
                }
            }
        }
        registerReceiver(mUsbBroadcastReceiver, filter)
    }

    private fun unregisterUsbReceiver() {
        unregisterReceiver(mUsbBroadcastReceiver)
    }

普通USB设备（U盘）

    private fun initUsbDeviceReceiver() {
        val filter = IntentFilter()
        filter.addAction("android.hardware.usb.action.USB_DEVICE_ATTACHED")
        filter.addAction("android.hardware.usb.action.USB_DEVICE_DETACHED")
        mUsbBroadcastReceiver = object : BroadcastReceiver() {
            override fun onReceive(context: Context, intent: Intent) {
                val action = intent.action
                if (action == "android.hardware.usb.action.USB_DEVICE_ATTACHED") {
                    val usbManager: UsbManager = getSystemService(Context.USB_SERVICE) as UsbManager
                    val deviceList = usbManager.deviceList
                    Log.e("zh", "设备连接 设备数目：${deviceList.size}")
                    deviceList.forEach { Log.e("zh", " 设备：${it}") }
                }
                if (action == "android.hardware.usb.action.USB_DEVICE_DETACHED") {
                    val usbManager: UsbManager = getSystemService(Context.USB_SERVICE) as UsbManager
                    val deviceList = usbManager.deviceList
                    Log.e("zh", "设备断开 设备数目：${deviceList.size}")
                    deviceList.forEach { Log.e("zh", " 设备：${it}") }
                }
            }
        }
        registerReceiver(mUsbBroadcastReceiver, filter)
    }

    private fun unregisterUsbDeviceReceiver() {
        unregisterReceiver(mUsbBroadcastReceiver)
    }

输入型USB设备（鼠标，键盘）

    private val mInputManager by lazy { getSystemService(Context.INPUT_SERVICE) as InputManager }private fun initEnterUsbDeviceReceiver() {
        mInputDeviceListener = object : InputManager.InputDeviceListener {
            override fun onInputDeviceAdded(deviceId: Int) {
                val device = mInputManager.getInputDevice(deviceId)
                Log.e("zh", "onInputDeviceAdded: ${device.name}")

            }

            override fun onInputDeviceRemoved(deviceId: Int) {

            }

            override fun onInputDeviceChanged(deviceId: Int) {

            }

        }
        mInputManager.registerInputDeviceListener(mInputDeviceListener, null)

    }

    private fun unregisterEnterUsbDeviceReceiver() {
        mInputManager.unregisterInputDeviceListener(mInputDeviceListener)
    }

U盘文件操作

推荐使用，下面这个第三方框架 

implementation 'com.github.mjdev:libaums:0.5.5'

参考代码

private fun getMassStorageDevices(){
    val devices = UsbMassStorageDevice.getMassStorageDevices(this)
    for (itemDevice in devices){
        itemDevice.init()
        if (itemDevice == null || itemDevice.getPartitions() == null ||
            itemDevice.getPartitions().get(0) == null ||
            itemDevice.getPartitions().get(0).getFileSystem() == null) {
            return
        }
        //getPartitions为得到分区
        //get(0)是挂载的USB设备数量
        val fileSystem = itemDevice.getPartitions().get(0).getFileSystem()
        //根目录
        val root = fileSystem.rootDirectory
        //获取当前目录文件列表
        val fileArray = root.listFiles()
        for (file in fileArray){
            Log.e("zh", "文件名称 = ${file.name}")
            Log.e("zh", "是否是根目录 = ${file.isRoot}")
            Log.e("zh", "是否是目录 = ${file.isDirectory}")
            Log.e("zh", "上一级目录 = ${file.parent}")
            Log.e("zh", "文件长度 = ${file.length}")

            //val in = UsbFileInputStream(file);  输入流
            //val ou = UsbFileOutputStream(file) 输出流
            //file.createFile() 创建文件
            //file.createDirectory() 创建目录
            //file.delete()  删除文件
        }
    }
}

 

 

 

 

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