android usb host 模式下监听usb的拔插

成长来源于坚持不懈的努力。每天都在进步，不在乎进步的多少，量变最终形成质变！

usb host模式的书面叙述我就不多说了，我就谈谈我的理解，其实usb host模式其实就是电脑的usb口模式，这情况你可以改变硬件外接电脑的usb口，也可以是原来的usb口外接转换口，如OTG。这时候用SD的拔插广播

Intent.ACTION_MEDIA_MOUNTED   //sd卡挂载

Intent.ACTION_MEDIA_EJECT   //sd 卡移除

是监听不到usb host的鼠标，u盘等拔插的。

这时候就要用到

android.hardware.usb.action.USB_DEVICE_ATTACHED  
android.hardware.usb.action.USB_DEVICE_DETACHED

网上对于这两个广播的描述都是千篇一律，其实也两个广播可以静态监听，也可以动态监听，还可以实行设备过滤。

静态监听

和其他广播一样，只需要在AndroidManifest.xml里面注册这两个广播就可以了

最主要的是加上权限

然后在activity里面进行处理

public class braost extends BroadcastReceiver {
    @Override
    public void onReceive(final Context context, Intent intent) {
        String action = intent.getAction();

        if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {

            Log.e("pangsheng", "静态广播接收器设备插入");

        } else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
            Log.e("pangsheng", "静态广播接收器设备拔出");

        }
    }
}

动态注册

      IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
        intentFilter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
        intentFilter.addDataScheme("file");
        registerReceiver(broadcastRec, intentFilter);

 private final BroadcastReceiver broadcastRec = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

            String action = intent.getAction();      
            if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
                Log.e("pangsheng", "usb attached");
            }
            if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
                Log.e("pangsheng", "usb unattached ");
            }
        }
    };

设备过滤

这个其实就是静态注册，只不过是可以自定义打开自己的activity，多用于游戏设备，还可以实现弹窗让用户选择

在AndroidManifest.xml对应的activity加上

  
            
                
                        
    
  
 
  记得权限很重要 
  
    
    
    
 
  
 
  

 
  
然后在xml文件夹建立
 
  
device_filter.xml
 
  
 
  
 
  
     
  
  
                                 
 
  
 
  
 
  
 
  
 
  
 
  
activity
 
  
 
  
    private static final String ACTION_USB_DEVICE_PERMISSION =
            "com.android.accessorydisplay.sink.ACTION_USB_DEVICE_PERMISSION";//用户确认时候打开
 
  
 
  
      IntentFilter filter = new IntentFilter();
        filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
        filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
        filter.addAction(ACTION_USB_DEVICE_PERMISSION);
        mReceiver = new DeviceReceiver();
        registerReceiver(mReceiver, filter);
 
  
 
  
class DeviceReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            UsbDevice device = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
            if (device != null) {
                String action = intent.getAction();
                if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
                    Log.e("pangsheng", "");
                } else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
                    Log.e("pangsheng", "");
                }   else if (action.equals(UsbManager.ACTION_USB_DEVICE_PERMISSION)) {
                    Log.e("pangsheng", "权限，用户确认");
                } 
 } } }