我想创建一个应用程序，通过USB从Android-app向PC发送数据。我的代码如下：
package com.sample.dummy.app.senddatathoughserialport;
import java.io.UnsupportedEncodingException;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.hardware.usb.UsbConstants;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import android.hardware.usb.UsbDevice;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity
{
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView tv = (TextView)findViewById(R.id.multiAutoCompleteTextView1);
Button sButton = (Button) findViewById(R.id.button1);
final UsbManager manager = (UsbManager) this.getSystemService(Context.USB_SERVICE);
Toaster(""+manager);
// -- register click event with first button ---
sButton.setOnClickListener(new View.OnClickListener()
{
@SuppressWarnings({ "unused" })
public void onClick(View v)
{
try
{
Intent intent = new Intent("android.hardware.usb.action.USB_DEVICE_ATTACHED");
UsbDevice mDevice = (UsbDevice) intent.getParcelableExtra(UsbManager.ACTION_USB_DEVICE_ATTACHED);
Toaster(""+mDevice);
final UsbDeviceConnection connection = manager.openDevice(mDevice);
UsbInterface usbIf = null;
Toaster("Its ok here 1");
int count = mDevice.getInterfaceCount();
Toaster("Its ok here 1");
for(int i=0; i< count; i++)
{
usbIf = mDevice.getInterface(i);
}
UsbEndpoint epIN = null;
UsbEndpoint epOUT = null;
Toaster("It's ok here 2");
for (int i = 0; i < usbIf.getEndpointCount(); i++)
{
if (usbIf.getEndpoint(i).getType() == UsbConstants.USB_ENDPOINT_XFER_BULK)
{
if (usbIf.getEndpoint(i).getDirection() == UsbConstants.USB_DIR_IN)
epIN = usbIf.getEndpoint(i);
else
epOUT = usbIf.getEndpoint(i);
}
else
{
Log.d("USB","Not Bulk");
Toaster("Thedaa log daggara");
}
}
String get = tv.getText().toString();
try
{
byte[] str = get.getBytes(get);
connection.bulkTransfer(epOUT, str, str.length, 500);
}
catch (UnsupportedEncodingException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
Toaster("Data sending failed!");
}
finally
{
Toaster("Data sent through USB !");
}
}
catch(Exception e)
{
Log.d("Failed", e.toString());
Toaster("Attempt Failed !!");
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void Toaster(String string)
{
Toast.makeText(this, string,Toast.LENGTH_LONG).show();
}}
我的Android Manifest Xml文件如下：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.sample.dummy.app.senddatathoughserialport"
android:versionCode="1"
android:versionName="1.0" >
<uses-feature android:name="android.hardware.usb.host" />
<uses-sdk android:minSdkVersion="12" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.sample.dummy.app.senddatathoughserialport.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
<action android:name="android.hardware.usb.action.USB_DEVICE_DETACHED" />
</intent-filter>
<meta-data
android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
android:resource="@xml/device_filter" />
<meta-data
android:name="android.hardware.usb.action.USB_DEVICE_DETACHED"
android:resource="@xml/device_filter" />
</activity>
</application></manifest>
我遇到的问题UsbDevice mDevice;始终显示null的值
请给我助手让它成为一个成功的应用程序。
答案 0 :(得分：7)
在我们公司，我们使用以下代码打开具有特定ID的设备。它也只适用于OTG兼容设备。在你的Manifest中你不需要USB_DETACHED，因为manifest中的intent-filters意味着打开/启动你的app，除非你想在usb分离时打开你的apk。只需点击即可调用ConnectUSB;
UsbInterface usbInterface;
UsbEndpoint usbEndpointIN, usbEndpointOUT;
UsbDeviceConnection usbDeviceConnection;
UsbDevice deviceFound = null;
USB USB;
ArrayList<String> listInterface;
ArrayList<UsbInterface> listUsbInterface;
ArrayList<String> listEndPoint;
ArrayList<UsbEndpoint> listUsbEndpoint;
private static final int targetVendorID = 8260;
private static final int ProductID = 1000;
private boolean connectUsb() {
boolean result = false;
switch(checkDeviceInfo())
{
case ProductID:
result = StartUSB();
break;
}
return result;
}
private int checkDeviceInfo() {
deviceFound = null;
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> deviceList = manager.getDeviceList();
Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
while (deviceIterator.hasNext()) {
UsbDevice device = deviceIterator.next();
if(device.getVendorId()==targetVendorID) {
deviceFound = device;
switch(device.getProductId()) {
case ProductID:
GetInterface(deviceFound);
GetEndpoint(deviceFound);
return ProductID;
default:
Toast.makeText(this, getString(R.string.err_unknow_device), Toast.LENGTH_LONG).show();
break;
}
return -1;
}
}
return -1;
}
private void GetInterface(UsbDevice d) {
listInterface = new ArrayList<String>();
listUsbInterface = new ArrayList<UsbInterface>();
for(int i=0; i<d.getInterfaceCount(); i++){
UsbInterface usbif = d.getInterface(i);
listInterface.add(usbif.toString());
listUsbInterface.add(usbif);
}
if(d.getInterfaceCount() > 0)
{
usbInterface = listUsbInterface.get(1);
}
else usbInterface = null;
}
private void GetEndpoint(UsbDevice d) {
int EndpointCount = usbInterface.getEndpointCount();
listEndPoint = new ArrayList<String>();
listUsbEndpoint = new ArrayList<UsbEndpoint>();
for(int i=0; i<usbInterface.getEndpointCount(); i++) {
UsbEndpoint usbEP = usbInterface.getEndpoint(i);
listEndPoint.add(usbEP.toString());
listUsbEndpoint.add(usbEP);
}
// deixar fixo para TxBlock USB
if(EndpointCount > 0) {
usbEndpointIN = usbInterface.getEndpoint(0);
usbEndpointOUT = usbInterface.getEndpoint(1);
}
else {
usbEndpointIN = null;
usbEndpointOUT = null;
}
}
private boolean StartUSB() {
boolean result = false;
UsbDevice deviceToRead = deviceFound;
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
Boolean permitToRead = manager.hasPermission(deviceToRead);
if(permitToRead) {
result = OpenDevice(deviceToRead);
}else {
Toast.makeText(this,
getString(R.string.err_no_permission) + permitToRead,
Toast.LENGTH_LONG).show();
}
return result;
}
private boolean OpenDevice(UsbDevice device){
boolean forceClaim = true;
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
usbDeviceConnection = manager.openDevice(device);
if(usbDeviceConnection != null){
usbDeviceConnection.claimInterface(usbInterface, forceClaim);
return true;
}else{
Toast.makeText(this,
getString(R.string.err_no_open_device),
Toast.LENGTH_LONG).show();
}
return false;
}