声明：主要参照文档:
Android开发之USB数据通信
安卓USB通信之权限管理
第一：请求权限和请求权限回调（通过广播回调）
注册一个广播接收器用于接收USB权限被同意或拒绝后发出的广播
//注册USB设备权限管理广播
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION); //ACTION_USB_PERMISSION为自定义的字符串
context.registerReceiver(usbReceiver, filter);
其中usbReceiver的实现是：
private BroadcastReceiver usbReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if(action.equals(ACTION_USB_PERMISSION)){//ACTION_USB_PERMISSION是前面我们自己自定义的字符串
UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if (device != null) {
LogUtils.i("已获取USB权限");
}
} else {
LogUtils.i("USB权限被拒绝");
}
};
请求权限：
PendingIntent mPermissionIntent = PendingIntent.getBroadcast(context, 0, new Intent(ACTION_USB_PERMISSION), 0);//关于这个mPermissionIntent ，具体的作用我还没弄明白，明白以后补充
manager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
manager.requestPermission(device,mPermissionIntent);//device是具体某个usb设备
执行完这个后，界面会弹出对话框询问用户是否授予权限，然后会发送权限广播，所以上面我们注册一个广播接收器来判断权限状态
第二：注册USB设备插拔广播
USB设备被插/拔后同样会发送一个广播，因此我们需要注册一个接收器来接收这个广播
IntentFilter stateFilter = new IntentFilter();
stateFilter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
stateFilter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
context.registerReceiver(usbStateReceiver, stateFilter);
其中.usbStateReceiver的实现如下：
private BroadcastReceiver usbStateReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
//USB连接上手机时会发送广播android.hardware.usb.action.USB_STATE"及UsbManager.ACTION_USB_DEVICE_ATTACHED
if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
LogUtils.i("有USB设备连接");
} else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {//USB被拔出
LogUtils.i("USB连接断开，程序退出！");
}
}
};
详细介绍以上两种，另附一个自己写的USBUtil，里面的思路是，初始化话时传入要连接设备的VendorId和ProductId，然后自动进行搜索，连接，授权等。只暴露读/写，开/关给外界，其他的全部自己处理
未经测试，请勿直接使用，仅供参考！！！！
package com.police.policefaceproject.utils;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.usb.UsbConstants;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import java.util.Iterator;
import java.util.Map;
/**
* Created by Administrator on 2018/4/18.
*/
public class USBUtils {
private Activity activity;
private final String ACTION_USB_PERMISSION = "com.gudi.usb.permission";
private UsbManager manager;
private PendingIntent mPermissionIntent;
private BroadcastReceiver usbReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if(action.equals(ACTION_USB_PERMISSION)){
UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if (device != null) {
USBCtrl(context);
}
} else {
LogUtils.i("USB权限被拒绝");
if(activity!=null && !activity.isDestroyed()){
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
UiUtils.Alert(activity, "权限错误", "请重新插拔设备后，授予应用访问USB权限","确定", new UiUtils.AlertCallBackOne() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
});
;
}
});
}
}
}
}
};
private UsbDeviceConnection usbConnection;
private UsbEndpoint uepIn;
private UsbEndpoint uepOut;
private int mProductId,mVendorId;
private BroadcastReceiver usbStateReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
//USB连接上手机时会发送广播android.hardware.usb.action.USB_STATE"及UsbManager.ACTION_USB_DEVICE_ATTACHED
if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {//判断其中一个就可以了
LogUtils.i("有USB设备连接");
showMsg("有USB设备连接");
USBCtrl(context);
} else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {//USB被拔出
LogUtils.i("USB连接断开，程序退出！");
showMsg("USB连接断开，请重试");
closeConn();
}
}
};
public void init(Activity context,int productId,int vendorId){
activity = context;
mProductId = productId;
mVendorId = vendorId;
manager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
mPermissionIntent = PendingIntent.getBroadcast(context, 0, new Intent(ACTION_USB_PERMISSION), 0);
//注册USB设备权限管理广播
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
context.registerReceiver(usbReceiver, filter);
//注册USB设备插拔广播
IntentFilter stateFilter = new IntentFilter();
stateFilter.addAction(UsbManager.ACTION_USB_ACCESSORY_ATTACHED);
stateFilter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
stateFilter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
context.registerReceiver(usbStateReceiver, stateFilter);
}
private Map<String,UsbDevice> getDevices(){
if(manager != null){
Map<String,UsbDevice> deviceMap = manager.getDeviceList();
return deviceMap;
}
return null;
}
private UsbDeviceConnection openDevice(Context context,UsbDevice device){
if(manager.hasPermission(device)){
UsbDeviceConnection DeviceConnection = manager.openDevice(device);
return DeviceConnection;
}else{
LogUtils.i("请求USB权限");
manager.requestPermission(device,mPermissionIntent);
return null;
}
}
private void USBCtrl(Context context){
//获取设备列表
Map<String,UsbDevice> devicesList= getDevices();
if(devicesList == null || devicesList.size() <=0){
LogUtils.e("未查找到USB设备");
showMsg("未查找到设备，请重新插拔设备");
}else{
//遍历寻找指定设备
Iterator<UsbDevice> deviceIterator = devicesList.values().iterator();
while(deviceIterator.hasNext()){
UsbDevice usb= deviceIterator.next();
if(usb.getVendorId() == mVendorId && usb.getProductId() == mProductId){
//查找到指定设备
connDevice(context,usb);
break;
}
}
}
}
private void connDevice(Context context,UsbDevice device){
UsbEndpoint uep;
//获得设备接口
UsbInterface usbInterface = device.getInterface(0);
//查找输入，输出端
for(int i =0;i<usbInterface.getEndpointCount();i++){
uep=usbInterface.getEndpoint(i);
if(uep.getType() == UsbConstants.USB_ENDPOINT_XFER_BULK){
if(uep.getDirection() == UsbConstants.USB_DIR_IN){
uepIn = uep;
}else if(uep.getDirection() == UsbConstants.USB_DIR_OUT){
uepOut = uep;
}
}
}
usbConnection = openDevice(context,device);
if(usbConnection == null){
LogUtils.e("连接设备失败");
showMsg("连接设备失败，请赋予权限");
return ;
}
if(usbConnection.claimInterface(usbInterface,true)){//声明独占此接口，在发送或接收数据前完成
//锁定成功
}else{
//锁定失败
usbConnection.close();
usbConnection = null;
LogUtils.e("锁定接口失败");
showMsg("锁定接口失败，请插拔设备重试");
}
}
public int write(byte[] data){
if(usbConnection != null){
int len= usbConnection.bulkTransfer(uepOut, data, data.length, 3000);
LogUtils.i("通过USB接口发送"+data.length+"数据");
return len;
}else{
LogUtils.i("usbConnection为null");
return -1;
}
}
public byte[] read(byte[] data){
if(usbConnection != null){
int len= usbConnection.bulkTransfer(uepOut, data, data.length, 3000);
LogUtils.i("通过USB接口接收"+data.length+"数据");
return data;
}else{
LogUtils.i("接收数据，usbConnection为null");
return null;
}
}
public void closeConn(){
if(usbConnection != null){
usbConnection.close();
usbConnection=null;
}
}
private void showMsg(final String msg){
if(activity!=null ){
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
UiUtils.toast(activity.getApplicationContext(),msg);
}
});
}
}
}
