如何接收USB连接状态广播? [英] How to receive USB connection status broadcast?
问题描述
我正在尝试检测我的应用程序中的USB连接，即USB是否已连接到设备.
I am trying to detect USB connection in my app, that is, whether or not USB is connected to device.
正在棉花糖6.0.1(sdk23)上进行测试
It's being tested on Marshmallow 6.0.1 (sdk23)
但是我无法接收广播动作ACTION_USB_DEVICE_ATTACHED或ACTION_USB_DEVICE_DETACHED.
But I'm unable to receive the broadcast actions ACTION_USB_DEVICE_ATTACHED or ACTION_USB_DEVICE_DETACHED..
我尝试同时使用动态方式和AndroidManifest.xml方式，但均无效.
I tried using both the dynamic way and the AndroidManifest.xml way, neither worked..
这是我的代码:
AndroidManifest.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.gokulnc.blah_blah"
android:installLocation="auto"
android:versionCode="15"
android:versionName="1.5.1">
<uses-feature android:name="android.hardware.usb.host" />
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="23" />
<android:uses-permission android:name="android.permission.USB_PERMISSION" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:vmSafeMode="false">
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:theme="@style/DrawerTheme">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<receiver android:name="mUsbReceiver">
<intent-filter>
<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
</intent-filter>
<intent-filter>
<action android:name="android.hardware.usb.action.USB_DEVICE_DETACHED" />
</intent-filter>
</receiver>
</activity>
</application>
</manifest>
MainActivity.java :
public class MainActivity extends AppCompatActivity {
BroadcastReceiver mUsbReceiver;
public void onCreate(Bundle savedInstanceState) {
.....
setBroadcastReceivers();
}
void setBroadcastReceivers() {
//Reference: http://www.codepool.biz/how-to-monitor-usb-events-on-android.html
mUsbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
Log.d(LOG_TAG, "Received Broadcast: "+action);
if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action) || UsbManager.ACTION_USB_ACCESSORY_ATTACHED.equals(action)) {
updateUSBstatus();
Log.d(LOG_TAG, "USB Connected..");
} else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action) || UsbManager.ACTION_USB_ACCESSORY_DETACHED.equals(action)) {
UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (device != null) {
updateUSBstatus();
}
Log.d(LOG_TAG, "USB Disconnected..");
}
}
};
IntentFilter filter = new IntentFilter();
filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
//filter.addAction(UsbManager.ACTION_USB_ACCESSORY_ATTACHED);
//filter.addAction(UsbManager.ACTION_USB_ACCESSORY_DETACHED);
registerReceiver(mUsbReceiver , filter);
Log.d(LOG_TAG, "mUsbReceiver Registered");
}
@Override
public void onResume() {
super.onResume();
Log.d(LOG_TAG, "App Resumed..");
//Refernce: https://stackoverflow.com/questions/18015656/cant-receive-broadcast-intent-of-usbmanager-action-usb-device-attached-usbmanag
Intent intent = getIntent();
if (intent != null) {
if (intent.getAction().equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
Toast.makeText(getApplicationContext(), "Attached", Toast.LENGTH_SHORT).show();
} else if(intent.getAction().equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
Toast.makeText(getApplicationContext(), "Detached", Toast.LENGTH_SHORT).show();
}
}
}
}
我还检查了以下答案:可以没有收到UsbManager.ACTION_USB_DEVICE_ATTACHED/UsbManager.ACTION_USB_DEVICE_DETACHED的广播意图，但没有帮助..
I also checked this answer: Can't receive broadcast Intent of UsbManager.ACTION_USB_DEVICE_ATTACHED/UsbManager.ACTION_USB_DEVICE_DETACHED, but it didn't help..
有人可以指出我错了吗?
Can someone please point out where I'm wrong??
推荐答案
也许不起作用的原因是，自Android 6.0起，默认的USB模式为Charging，也许ACTION_USB_DEVICE_ATTACHED不会在启动时启动以该模式连接..
Maybe the reason it doesn't work is that since Android 6.0, the default USB mode is Charging and, maybe ACTION_USB_DEVICE_ATTACHED doesn't get fired up when connected in that mode..
相反，现在我有另一种解决方案:
String usbStateChangeAction = "android.hardware.usb.action.USB_STATE";
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
Log.d(LOG_TAG, "Received Broadcast: "+action);
if(action.equalsIgnoreCase(usbStateChangeAction)) { //Check if change in USB state
if(intent.getExtras().getBoolean("connected")) {
// USB was connected
} else {
// USB was disconnected
}
}
}
也就是说，只要USB状态发生切换，就会发送广播android.hardware.usb.action.USB_STATE.
That is, the broadcast android.hardware.usb.action.USB_STATE is sent whenever there is a toggle in the USB state.
与android.hardware.usb.action.USB_DEVICE_ATTACHED不同，android.hardware.usb.action.USB_DEVICE_ATTACHED仅在启用MTP模式之类的内容时才广播，而android.hardware.usb.action.USB_STATE每当它检测到能够连接到主机(例如计算机)的USB连接时就广播，而不考虑其当前的USB模式如充电，MTP或其他任何方式.(更精确的称为USB配置)
Unlike android.hardware.usb.action.USB_DEVICE_ATTACHED which is broadcasted only when something like a MTP mode is enable, android.hardware.usb.action.USB_STATE is broadcasted whenever it detects an USB connection that's capable of connecting to a host (say computer), irrespective of its current USB Mode like Charging, MTP or whatever.. (it's called USB config to be more precise)
这篇关于如何接收USB连接状态广播?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
