簡介

QtActivity 作為 Qt 應用程序的入口點，負責啟動和配置 Qt 應用程序的信息， 后面我們繼承 QtActivity 做自定義控制，了解一下 Activity 生命周期概念， 因為 QtActivity 繼承自Android的activity，使用周期函數完成我們的任務。

步驟

1. 獲取UsbManager

參考 UsbManager（apiref.com）， 通過下面代碼獲取USB服務
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);

2. 獲取getDeviceList

UsbManager 對象接口中， 我們使用如下代碼獲取usb設備列表 HashMap<String, UsbDevice> getDeviceList()

3. UsbDevice

UsbDevice接口如下, 打印設備的PID、VID、SN等基本信息即可
接口參考文檔 USBDevice 接口說明文檔

<class name="android/hardware/usb/UsbDevice" since="12"><extends name="java/lang/Object"/><implements name="android/os/Parcelable"/><method name="getConfiguration(I)Landroid/hardware/usb/UsbConfiguration;" since="21"/><method name="getConfigurationCount()I" since="21"/><method name="getDeviceClass()I"/><method name="getDeviceId()I"/><method name="getDeviceId(Ljava/lang/String;)I"/><method name="getDeviceName()Ljava/lang/String;"/><method name="getDeviceName(I)Ljava/lang/String;"/><method name="getDeviceProtocol()I"/><method name="getDeviceSubclass()I"/><method name="getInterface(I)Landroid/hardware/usb/UsbInterface;"/><method name="getInterfaceCount()I"/><method name="getManufacturerName()Ljava/lang/String;" since="21"/><method name="getProductId()I"/><method name="getProductName()Ljava/lang/String;" since="21"/><method name="getSerialNumber()Ljava/lang/String;" since="21"/><method name="getVendorId()I"/><method name="getVersion()Ljava/lang/String;" since="23"/><field name="CREATOR"/></class>

4. 代碼

package usb;import java.util.HashMap;
import android.os.Bundle;
import android.content.Context;
import android.hardware.usb.UsbManager;
import android.hardware.usb.UsbDevice;public class USBListActivity extends org.qtproject.qt.android.bindings.QtActivity
{private UsbManager m_usbManager;public USBListActivity(){}@Overridepublic void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);m_usbManager = (UsbManager)getSystemService(Context.USB_SERVICE);getDeviceList();}public void getDeviceList(){HashMap<String, UsbDevice> deviceList = m_usbManager.getDeviceList();System.out.println("------------------------->GetDeviceList<-------------------------");deviceList.forEach((key, value) -> {System.out.println("------------------------->" + key + "<-------------------------");System.out.println(value);System.out.println("<-------------------------" + key + "------------------------->");});System.out.println("<-------------------------GetDeviceList------------------------->");}
}

5. 設置你的代碼為啟動入口

編輯 AndroidManifest.xml， 將
android:name=“org.qtproject.qt.android.bindings.QtActivity”
改為
android:name=“usb.USBListActivity”
代碼目錄如下

6. 收集設備連接

我使用OTG線連接了USB擴展線， 在擴展上接了兩個同樣型號的USB轉TTL線， 如下圖

7. 運行結果

I System.out: ------------------------->GetDeviceList<-------------------------
I System.out: ------------------------->/dev/bus/usb/001/008<-------------------------
I System.out: UsbDevice[mName=/dev/bus/usb/001/008,mVendorId=6790,mProductId=29987,mClass=255,mSubclass=0,mProtocol=0,mManufacturerName=null,mProductName=USB2.0-Serial,mVersion=2.54,mSerialNumberReader=android.hardware.usb.IUsbSerialReader$Stub$Proxy@a1e1d4b, mHasAudioPlayback=false, mHasAudioCapture=false, mHasMidi=false, mHasVideoCapture=false, mHasVideoPlayback=false, mConfigurations=[
I System.out: UsbConfiguration[mId=1,mName=null,mAttributes=128,mMaxPower=48,mInterfaces=[
I System.out: UsbInterface[mId=0,mAlternateSetting=0,mName=null,mClass=255,mSubclass=1,mProtocol=2,mEndpoints=[
I System.out: UsbEndpoint[mAddress=130,mAttributes=2,mMaxPacketSize=32,mInterval=0]
I System.out: UsbEndpoint[mAddress=2,mAttributes=2,mMaxPacketSize=32,mInterval=0]
I System.out: UsbEndpoint[mAddress=129,mAttributes=3,mMaxPacketSize=8,mInterval=1]]]]
I System.out: <-------------------------/dev/bus/usb/001/008------------------------->
I System.out: ------------------------->/dev/bus/usb/001/007<-------------------------
I System.out: UsbDevice[mName=/dev/bus/usb/001/007,mVendorId=6790,mProductId=29987,mClass=255,mSubclass=0,mProtocol=0,mManufacturerName=null,mProductName=USB2.0-Serial,mVersion=2.54,mSerialNumberReader=android.hardware.usb.IUsbSerialReader$Stub$Proxy@ec18328, mHasAudioPlayback=false, mHasAudioCapture=false, mHasMidi=false, mHasVideoCapture=false, mHasVideoPlayback=false, mConfigurations=[
I System.out: UsbConfiguration[mId=1,mName=null,mAttributes=128,mMaxPower=48,mInterfaces=[
I System.out: UsbInterface[mId=0,mAlternateSetting=0,mName=null,mClass=255,mSubclass=1,mProtocol=2,mEndpoints=[
I System.out: UsbEndpoint[mAddress=130,mAttributes=2,mMaxPacketSize=32,mInterval=0]
I System.out: UsbEndpoint[mAddress=2,mAttributes=2,mMaxPacketSize=32,mInterval=0]
I System.out: UsbEndpoint[mAddress=129,mAttributes=3,mMaxPacketSize=8,mInterval=1]]]]
I System.out: <-------------------------/dev/bus/usb/001/007------------------------->
I System.out: <-------------------------GetDeviceList------------------------->

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andoid開發文檔

UsbManager（apiref.com）

UsbManager android-doc.com

UsbManager（matools.com）

Activity 生命周期概念

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Qt for android 錯誤處理

Qt for Android 亂碼問題

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其他

Qt for android 文檔（thinkinginqt.com）

Qt for android 官方文檔(Qt6.2LTS)

Qt Project to Manifest Configuration