Question

我使用动态广播可以接收UsbManager.ACTION_USB_DEVICE_ATTACHED和UsbManager.ACTION_USB_DEVICE_DETACHED事件。

但是当我的应用未运行时，USB设备已插入，动态广播无法接收到它。因此，我想在我的应用首次运行时进行检查。

我使用静态广播可以接收事件，但是我不想使用该方法，是否还有其他方法？

Answer 1

您可以使用UsbManager类并获取已连接设备的列表，请尝试使用以下方法并在onCreate中调用它

private void findSerialPortDevice() {
    // This snippet will try to open the first encountered usb device connected, excluding usb root hubs
    UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
    HashMap<String, UsbDevice> usbDevices = usbManager.getDeviceList();

    if (!usbDevices.isEmpty()) {
        boolean keep = true;
        for (Map.Entry<String, UsbDevice> entry : usbDevices.entrySet()) {
            device = entry.getValue();
            int deviceVID = device.getVendorId();
            int devicePID = device.getProductId();
            intf = device.getInterface(0);
            if(device != null && !device.equals(""))
                Utils.writeIntoFile(getBaseContext(),"device =============>"+device+"\n"+"getInterface Count =============>"+device.getInterfaceCount());
                // There is a device connected to our Android device. Try to open it as a Serial Port.
            } else {
                    connection = null;
                    device = null;
                }
            }

            if (!keep)
                break;
        }
        if (!keep) {
            // There is no USB devices connected.

        }
    } else {
        // There is no USB devices connected.
    }
}

Answer 2

如果要在连接设备后启动应用，则必须在清单中注册USB设备的VID / PID

<activity
    android:name="..."
    ...>
    <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" />
</activity>

和device_filter.xml：

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- 0x0403 / 0x6001: FTDI FT232R UART -->
    <usb-device vendor-id="1027" product-id="24577" />
...

例如如here

检查USB设备是否已插入

2 个答案: