如何检测可用于存储的已安装设备(如Pen-Drive)？如何找到安装的存储设备的路径，以便我可以从中读取文件？USBdevice识别为存储设备并找到路径
我用下面取权限访问安装器件广播接收机：
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_USB_PERMISSION.equals(action)) {
synchronized (this) {
UsbDevice device = (UsbDevice) intent
.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(
UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if (device != null) {
// call method to set up device communication
Log.d(TAG, "onReceive: "+intent.getExtras().toString());
Log.d(TAG, "onReceive: "+intent.getData());
LinearLayout layoutUsbList = (LinearLayout)findViewById(R.id.layout_usb_list);
Button btn = new Button(MainActivity.this);
btn.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
layoutUsbList.addView(btn);
btn.setText(device.getDeviceId()+"\t"+device.getDeviceName());
Log.d(TAG, "onReceive: "+intent.getExtras().toString());
final String path = intent.getData().getPath();
Log.e(TAG, "onReceive: path of device received from intent: "+ path);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
File file = new File(path);
Toast.makeText(MainActivity.this, "file exists --> "+file.exists()+"", Toast.LENGTH_SHORT).show();
Toast.makeText(MainActivity.this, "file is directory --> "+file.isDirectory()+"", Toast.LENGTH_SHORT).show();
Log.d(TAG, "onClick: file is directory --> "+file.isDirectory()+"");
try{
Toast.makeText(MainActivity.this, file.listFiles().length+"", Toast.LENGTH_LONG).show();
}catch(Exception e){
Toast.makeText(MainActivity.this, "error while showing total items", Toast.LENGTH_SHORT).show();
}
}
});
}
} else {
Log.d("ERROR", "permission denied for device " + device);
}
}
}
}
};
清单文件：
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme">
android:name=".MainActivity"
android:configChanges="keyboard|orientation"
android:label="@string/app_name">
android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
android:resource="@xml/device_filter"/>
-01-27
A_rmas
