MainUsbActivity.java

/** * MainUsbActivity is a GameActivity that monitors a USB Accessory * device and uses the input from that device to control the game. */package com.examples.accessory.controller;import android.app.PendingIntent;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.hardware.usb.UsbAccessory;import android.hardware.usb.UsbManager;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.os.ParcelFileDescriptor;import android.util.Log;import java.io.FileDescriptor;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;public class MainUsbActivity extends GameActivity implements Runnable {private static final String ACTION_USB_PERMISSION = "com.examples.accessory.controller.action.USB_PERMISSION";private UsbManager mUsbManager;private PendingIntent mPermissionIntent;private boolean mPermissionRequestPending;UsbAccessory mAccessory;ParcelFileDescriptor mFileDescriptor;FileInputStream mInputStream;FileOutputStream mOutputStream;private static final int MESSAGE_SWITCH = 1;private static final int MESSAGE_JOY = 4;    private static final int MESSAGE_VIBE = 5;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);mUsbManager = (UsbManager)getSystemService(Context.USB_SERVICE);mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);filter.addAction(UsbManager.ACTION_USB_ACCESSORY_DETACHED);registerReceiver(mUsbReceiver, filter);setContentView(R.layout.main);enableControls(false);}@Overridepublic void onResume() {super.onResume();Intent intent = getIntent();if (mInputStream != null && mOutputStream != null) {return;}UsbAccessory[] accessories = mUsbManager.getAccessoryList();UsbAccessory accessory = (accessories == null ? null : accessories[0]);if (accessory != null) {if (mUsbManager.hasPermission(accessory)) {openAccessory(accessory);} else {synchronized (mUsbReceiver) {if (!mPermissionRequestPending) {mUsbManager.requestPermission(accessory,                                mPermissionIntent);mPermissionRequestPending = true;}}}} else {Log.d(TAG, "mAccessory is null");}}@Overridepublic void onPause() {super.onPause();closeAccessory();}@Overridepublic void onDestroy() {unregisterReceiver(mUsbReceiver);super.onDestroy();}@Overrideprotected boolean isControllerConnected() {    return (mAccessory != null);}@Overrideprotected void hideControls() {    setContentView(R.layout.no_device);    super.hideControls();}    @Override    protected void sendVibeControl(boolean longDuration) {        byte[] command = {0x02,                longDuration ? (byte)0x64 : (byte)0x32,                0x00};        Message msg = Message.obtain(null, MESSAGE_VIBE, command);        mHandler.sendMessage(msg);    }    private void openAccessory(UsbAccessory accessory) {mFileDescriptor = mUsbManager.openAccessory(accessory);if (mFileDescriptor != null) {mAccessory = accessory;FileDescriptor fd = mFileDescriptor.getFileDescriptor();mInputStream = new FileInputStream(fd);mOutputStream = new FileOutputStream(fd);Thread thread = new Thread(null, this, "AccessoryController");thread.start();Log.d(TAG, "accessory opened");enableControls(true);} else {Log.d(TAG, "accessory open fail");}}private void closeAccessory() {enableControls(false);try {if (mFileDescriptor != null) {mFileDescriptor.close();}} catch (IOException e) {} finally {mFileDescriptor = null;mAccessory = null;}}/* * This receiver monitors for the event of a user granting permission to use * the attached accessory.  If the user has checked to always allow, this will * be generated following attachment without further user interaction. */    private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {        @Override        public void onReceive(Context context, Intent intent) {            String action = intent.getAction();            if (ACTION_USB_PERMISSION.equals(action)) {                synchronized (this) {                    UsbAccessory accessory = (UsbAccessory) intent.getParcelableExtra(UsbManager.EXTRA_ACCESSORY);                    if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {                        openAccessory(accessory);                    } else {                        Log.d(TAG, "permission denied for accessory "+ accessory);                    }                    mPermissionRequestPending = false;                }            } else if (UsbManager.ACTION_USB_ACCESSORY_DETACHED.equals(action)) {                UsbAccessory accessory = (UsbAccessory) intent.getParcelableExtra(UsbManager.EXTRA_ACCESSORY);                if (accessory != null && accessory.equals(mAccessory)) {                    closeAccessory();                }            }        }    };/* * Runnable block that will poll the accessory data stream * for regular updates, posting each message it finds to a * Handler.  This is run on a spawned background thread. */public void run() {int ret = 0;byte[] buffer = new byte[16384];int i;while (ret >= 0) {try {ret = mInputStream.read(buffer);} catch (IOException e) {break;}i = 0;while (i < ret) {int len = ret - i;switch (buffer[i]) {case 0x1:if (len >= 3) {Message m = Message.obtain(mHandler, MESSAGE_SWITCH);m.obj = new SwitchMsg(buffer[i + 1], buffer[i + 2]);mHandler.sendMessage(m);}i += 3;break;case 0x6:if (len >= 3) {Message m = Message.obtain(mHandler, MESSAGE_JOY);m.obj = new JoyMsg(buffer[i + 1], buffer[i + 2]);mHandler.sendMessage(m);}i += 3;break;default:Log.d(TAG, "unknown msg: " + buffer[i]);i = len;break;}}}}/* * This Handler receives messages from the polling thread and * injects them into the GameActivity methods on the main thread. */    Handler mHandler = new Handler() {        @Override        public void handleMessage(Message msg) {            switch (msg.what) {                case MESSAGE_SWITCH:                    SwitchMsg o = (SwitchMsg) msg.obj;                    handleSwitchMessage(o);                    break;                case MESSAGE_JOY:                    JoyMsg j = (JoyMsg) msg.obj;                    handleJoyMessage(j);                    break;                case MESSAGE_VIBE:                    try {                        byte[] v = (byte[]) msg.obj;                        mOutputStream.write(v);                        mOutputStream.flush();                    } catch (IOException e) {                        Log.w("AccessoryController", "Error writing vibe output");                    }                    break;            }        }    };}

转自：https://github.com/devunwired/accessory-samples/blob/master/AccessoryController/src/com/examples/accessory/controller/MainUsbActivity.java