需求：
* 通过otg线使手机连接u盘，并获取到u盘的文件信息
-
manifest注册权限
<!--获取读取OTG和文件权限-->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.hardware.usb.host" android:required="false" />
<!--因为部分手机上是没有otg的所以需要加入特性-->
<uses-feature
android:name="android.hardware.usb.host"/>
-
mainfest 静态注册页面,在mainactivity中配置属性
<!--不指定设备-->
<intent-filter>
<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"/>
</intent-filter>
<meta-data
android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
android:resource="@xml/device_filter" />
<!--device_filter-->
<?xml version="1.0" encoding="utf-8"?>
<resources>
<usb-device
class="8"
protocol="80"
subclass="6" />
</resources>
<!--指定设备-->
<!--<intent-filter>
<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"/>
</intent-filter>
<meta-data
android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
android:resource="@xml/device_filter" />
<?xml version="1.0" encoding="utf-8"?>
<resources>
<usb-device vendor-id="1155"
product-id="22336"
/>
</resources>-->
-
onCreat中注册广播
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
registerReceiver(mUsbReceiver, filter);
discoverDevice();
广播：
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
switch (action) {
case ACTION_USB_PERMISSION://接受到自定义广播
synchronized (this) {
UsbDevice usbDevice = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) { //允许权限申请
if (usbDevice != null) {
//Do something
setupDevice();
}
} else {
Toast.makeText(context, "用户未授权，读取失败", Toast.LENGTH_SHORT).show();
}
}
break;
case UsbManager.ACTION_USB_DEVICE_ATTACHED://接收到存储设备插入广播
UsbDevice device_add = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (device_add != null) {
Toast.makeText(context, "接收到存储设备插入广播", Toast.LENGTH_SHORT).show();
discoverDevice();
}
break;
case UsbManager.ACTION_USB_DEVICE_DETACHED://接收到存储设备拔出广播
UsbDevice device_remove = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (device_remove != null) {
Toast.makeText(context, "接收到存储设备拔出广播", Toast.LENGTH_SHORT).show();
discoverDevice();
}
break;
}
}
};
-
发现设备
private void discoverDevice() {
UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
massStorageDevices = UsbMassStorageDevice.getMassStorageDevices(this);
if (massStorageDevices.length == 0) {
Log.w(TAG, "no device found!");
Toast.makeText(MainActivity.this, "没有设备",Toast.LENGTH_SHORT).show();
listView.setAdapter(null);
return;
}
currentDevice = 0;
UsbDevice usbDevice = (UsbDevice) getIntent().getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (usbDevice != null && usbManager.hasPermission(usbDevice)) {
Log.d(TAG, "received usb device via intent");
// requesting permission is not needed in this case
Toast.makeText(MainActivity.this, "接受到usb",Toast.LENGTH_SHORT).show();
setupDevice();
} else {
// first request permission from user to communicate with the
// underlying
// UsbDevice
Toast.makeText(MainActivity.this, "usbDevice==nil",Toast.LENGTH_SHORT).show();
PendingIntent permissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(
ACTION_USB_PERMISSION), 0);
usbManager.requestPermission(massStorageDevices[currentDevice].getUsbDevice(), permissionIntent);
}
}
-
读取设备信息
private void setupDevice() {
try {
massStorageDevices[currentDevice].init();
// we always use the first partition of the device
currentFs = massStorageDevices[currentDevice].getPartitions().get(0).getFileSystem();
Log.d(TAG, "Capacity: " + currentFs.getCapacity());
Log.d(TAG, "Occupied Space: " + currentFs.getOccupiedSpace());
Log.d(TAG, "Free Space: " + currentFs.getFreeSpace());
Log.d(TAG, "Chunk size: " + currentFs.getChunkSize());
Toast.makeText(MainActivity.this, "设备目录"+currentFs.getRootDirectory(),Toast.LENGTH_SHORT).show();
UsbFile root = currentFs.getRootDirectory();
adapter = new UsbFileListAdapter(this, root);
listView.setAdapter(adapter);
} catch (IOException e) {
Log.e(TAG, "error setting up device", e);
Toast.makeText(MainActivity.this, "错误",Toast.LENGTH_SHORT).show();
}
}
注意：
1、使用的开源的：compile 'com.github.mjdev:libaums:0.5.3'
2、fs的支持：compile 'com.github.magnusja:java-fs:+'
需要配置：
java classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.7.3' classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
- 由于本人是从事的iOS的开发，这个只是临时的一个小任务，所以没有深入了解，后续继续深入的话会继续写下去的！
下一节：android读取单反的数据
