Android USB Host示例在Android Studio中不起作用

Question

我在http://mobilemerit.com/android-app-for-usb-host-with-source-code/#找到了以下示例。 该代码旨在列出已连接的USB设备，但无法在Android Studio中进行编译。 我想知道什么才能使其编译和运行？

activity_main.xml

 <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:orientation="vertical" tools:context=".MainActivity" > <button android:id="@+id/check" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Check USB devices"></button> <textview android:id="@+id/info" android:layout_width="match_parent" android:layout_height="wrap_content"></textview> </linearlayout> 

MainActivity.java

 package com.mobilemerit.usbhost; import java.util.HashMap; import java.util.Iterator; import android.app.Activity; import android.app.PendingIntent; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.hardware.usb.UsbDevice; import android.hardware.usb.UsbManager; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.TextView; import com.mobilemerit.usbhost.R; public class MainActivity extends Activity { PendingIntent mPermissionIntent; Button btnCheck; TextView textInfo; UsbDevice device; UsbManager manager; private static final String ACTION_USB_PERMISSION = "com.mobilemerit.usbhost.USB_PERMISSION"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btnCheck = (Button) findViewById(R.id.check); textInfo = (TextView) findViewById(R.id.info); btnCheck.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { textInfo.setText(""); checkInfo(); } }); } private void checkInfo() { manager = (UsbManager) getSystemService(Context.USB_SERVICE); /* * this block required if you need to communicate to USB devices it's * take permission to device * if you want than you can set this to which device you want to communicate */ // ------------------------------------------------------------------ mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent( ACTION_USB_PERMISSION), 0); IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION); registerReceiver(mUsbReceiver, filter); // ------------------------------------------------------------------- HashMap<string , UsbDevice> deviceList = manager.getDeviceList(); Iterator<usbdevice> deviceIterator = deviceList.values().iterator(); String i = ""; while (deviceIterator.hasNext()) { device = deviceIterator.next(); manager.requestPermission(device, mPermissionIntent); i += "\\n" + "DeviceID: " + device.getDeviceId() + "\\n" + "DeviceName: " + device.getDeviceName() + "\\n" + "DeviceClass: " + device.getDeviceClass() + " - " + "DeviceSubClass: " + device.getDeviceSubclass() + "\\n" + "VendorID: " + device.getVendorId() + "\\n" + "ProductID: " + device.getProductId() + "\\n"; } textInfo.setText(i); } 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 } } else { Log.d("ERROR", "permission denied for device " + device); } } } } }; } 

Manfest.xml

 < ?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.mobilemerit.usbhost" android:versionCode="1" android:versionName="1.0" > <uses -feature android:name="android.hardware.usb.host"></uses> <uses -sdk android:minSdkVersion="12" android:targetSdkVersion="19"></uses> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.mobilemerit.usbhost.MainActivity" android:label="@string/app_name" > <intent -filter> <action android:name="android.intent.action.MAIN"></action> <category android:name="android.intent.category.LAUNCHER"></category> </intent> </activity> </application> </manifest> 

Answer 1

在Android Studio中，您可以选择“导入项目”，然后选择放置USB示例文件的文件夹。 选择顶级文件夹。 之后，Android Studio将为您构建项目。 如果遇到错误或Android Studio需要下载文件，则应让其执行。 然后单击菜单：生成->重建项目。 全部做完！

这是已构建并可以运行的文件： AS USB示例工作该示例由mobilemerit提供。

这是该应用程序在我的Samsung上运行时Android Studio的屏幕截图。Note 3： 在Note 3上运行的USB示例图片

PS。 我绝不隶属于mobilemerit。

Answer 2

我有Android Studio版本1.3。 我更正了1.3的差异。 确保输入的应用程序名称为：

USB主机

对于公司名称，请输入：

mobilemerit.com

这将为您提供正确的软件包名称。 我的仿真器无法检测到USB设备。 因此，我使用了手机并将USB设备连接到它。

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:paddingBottom="@dimen/activity_vertical_margin"
              android:paddingLeft="@dimen/activity_horizontal_margin"
              android:paddingRight="@dimen/activity_horizontal_margin"
              android:paddingTop="@dimen/activity_vertical_margin"
              android:orientation="vertical"
              tools:context=".MainActivity" >

    <Button android:id="@+id/check"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Check USB devices" />

    <TextView android:id="@+id/info"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"/>

</LinearLayout>

MainActivity.java

package com.mobilemerit.usbhost;
import java.util.HashMap;
import java.util.Iterator;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbManager;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

import com.mobilemerit.usbhost.R;

public class MainActivity extends Activity {
    PendingIntent mPermissionIntent;
    Button btnCheck;
    TextView textInfo;
    UsbDevice device;
    UsbManager manager;
    private static final String ACTION_USB_PERMISSION = "com.mobilemerit.usbhost.USB_PERMISSION";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnCheck = (Button) findViewById(R.id.check);
        textInfo = (TextView) findViewById(R.id.info);
        btnCheck.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View arg0) {
                textInfo.setText("");
                checkInfo();
            }
        });

    }

    private void checkInfo() {
        manager = (UsbManager) getSystemService(Context.USB_SERVICE);
        /*
         * this block required if you need to communicate to USB devices it's
         * take permission to device
         * if you want than you can set this to which device you want to communicate
         */
        // ------------------------------------------------------------------
        mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(
                ACTION_USB_PERMISSION), 0);
        IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
        registerReceiver(mUsbReceiver, filter);
        // -------------------------------------------------------------------
        HashMap<String , UsbDevice> deviceList = manager.getDeviceList();
        Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
        String i = "";
        while (deviceIterator.hasNext()) {
            device = deviceIterator.next();
            manager.requestPermission(device, mPermissionIntent);
            i += "\n" + "DeviceID: " + device.getDeviceId() + "\n"
                    + "DeviceName: " + device.getDeviceName() + "\n"
                    + "DeviceClass: " + device.getDeviceClass() + " - "
                    + "DeviceSubClass: " + device.getDeviceSubclass() + "\n"
                    + "VendorID: " + device.getVendorId() + "\n"
                    + "ProductID: " + device.getProductId() + "\n";
        }

        textInfo.setText(i);
    }

    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
                        }
                    } else {
                        Log.d("ERROR", "permission denied for device " + device);
                    }
                }
            }
        }
    };
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.mobilemerit.usbhost"
          android:versionCode="1"
          android:versionName="1.0" >

<uses-feature android:name="android.hardware.usb.host"/>
<uses-sdk
    android:minSdkVersion="12"
    android:targetSdkVersion="19"/>

    <application android:allowBackup="true"
                 android:icon="@mipmap/ic_launcher"
                 android:label="@string/app_name"
                 android:theme="@style/AppTheme" >
        <activity android:name="com.mobilemerit.usbhost.MainActivity"
                  android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
    </application>
</manifest>