我创建了一个应用程序来检查 NFC 标签的负载，当它与应用程序匹配时切换蓝牙。
不幸的是，应用程序似乎进入了一个无限循环，它要求用户允许操作蓝牙，忽略选择并再次启动(再次询问相同的问题/Activity )。 onActivityResult 似乎没有被调用。
我的控制台日志调用的输出是:
Payload: 'quicktags-togglebluetooth'
Bluetooth should now be on
如果我继续在权限 Activity 上点击"is"，那么蓝牙会无限期地切换，并且控制台日志 (logcat) 如下所示:
Payload: quicktags-togglebluetooth
Bluetooth should now be on
Bluetooth should now be off
Bluetooth should now be on
Bluetooth should now be off
Bluetooth should now be on
Bluetooth should now be off
等等。
AndroidManifest 列出了正确的权限，请看下面:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.getquicktags.qt"
android:versionCode="1"
android:versionName="1.0" android:installLocation="auto">
<uses-sdk android:minSdkVersion="14" android:targetSdkVersion="14" />
<uses-permission android:name="android.permission.NFC" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-feature android:name="android.hardware.nfc" android:required="true" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name=".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>
<activity
android:name=".CardActivity"
android:label="@string/app_name" >
<!-- Handle a collectable card NDEF record -->
<intent-filter>
<action android:name="android.nfc.action.NDEF_DISCOVERED"/>
<data android:mimeType="application/vnd.getquicktags.qt"/>
<category android:name="android.intent.category.DEFAULT"/>
</intent-filter>
</activity>
</application>
</manifest>
可以在下面找到 CardActivity.java 文件，它启动了这个蓝牙困惑:
package com.getquicktags.qt;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.Intent;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.Log;
import android.bluetooth.*;
public class CardActivity extends Activity implements OnClickListener {
private static final String TAG = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.card_activity);
// see if app was started from a tag and show game console
Intent intent = getIntent();
if(intent.getType() != null && intent.getType().equals(MimeType.NFC_DEMO)) {
Parcelable[] rawMsgs = getIntent().getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
NdefMessage msg = (NdefMessage) rawMsgs[0];
NdefRecord cardRecord = msg.getRecords()[0];
String payload = new String(cardRecord.getPayload());
Log.d(TAG, "Payload: '"+ payload +"'");
if(payload.equals("quicktags-togglebluetooth")) {
toggleBluetooth();
}
}
}
private void toggleBluetooth() {
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
// Device does not support Bluetooth
Log.d(TAG, "No Bluetooth on device");
closeApp();
}
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 1);
Log.d(TAG, "Bluetooth should now be on");
} else {
// Turn it off
mBluetoothAdapter.disable();
Log.d(TAG, "Bluetooth should now be off");
closeApp();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// Close the app
Log.d(TAG, "Close the app call");
closeApp();
}
private void closeApp() {
Log.d(TAG, "And... close it. This is inside closeApp()");
android.os.Process.killProcess(android.os.Process.myPid());
}
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}
您可以看到，根据 logcat，onActivityResults 和 closeApp 不会被调用。
我正在 Nexus 7 上进行测试。标签没问题，我已经用各种 NFC 阅读器进行了测试。
扫描标签时，logcat 出现了一些错误，但它们对我来说似乎意义不大。见下文:
01-07 00:18:41.595: E/bt-btif(5830): btif_enable_service: current services:0x100020
01-07 00:18:41.605: E/bt-btif(5830): btif_enable_service: current services:0x140020
01-07 00:18:41.605: E/bt-btif(5830): btif_enable_service: current services:0x140020
01-07 00:18:42.415: E/bt-btif(5830): Calling BTA_HhEnable
01-07 00:18:42.415: E/btif_config.c(5830): ## btif_config_get assert section && *section && key && *key && name && *name && bytes && type failed at line:186 ##
01-07 00:18:42.415: E/bt-btif(5830): btif_storage_get_adapter_property service_mask:0x140020
01-07 00:18:42.435: E/btif_config.c(5830): ## btif_config_get assert section && *section && key && *key && name && *name && bytes && type failed at line:186 ##
01-07 00:18:42.445: E/bt_h4(5830): vendor lib postload completed
01-07 00:18:42.545: E/BluetoothServiceJni(5830): SOCK FLAG = 1 ***********************
01-07 00:18:42.605: E/BluetoothServiceJni(5830): SOCK FLAG = 0 ***********************
01-07 00:18:42.715: E/BtOppRfcommListener(5830): Error accept connection java.io.IOException: read failed, socket might closed, read ret: -1
01-07 00:18:42.915: E/bt-btif(5830): BTA AG is already disabled, ignoring ...
01-07 00:18:42.935: E/bt-btif(5830): btif_disable_service: Current Services:0x140020
01-07 00:18:42.945: E/bt-btif(5830): btif_disable_service: Current Services:0x100020
01-07 00:18:42.945: E/bt-btif(5830): btif_disable_service: Current Services:0x100020
非常感谢您对此提供的任何帮助。正如您可能想象的那样，它快把我逼疯了:)
最佳答案
为什么要终止 closeApp() 中的进程？我想这是你问题的一部分。只需在 Activity 上调用 finish()，让 Android 在需要时清理您的进程。
当您杀死您的进程时，Android 认为发生了不好的事情并尝试恢复。作为此恢复的一部分，它可能会重新传递可能不是您想要的 Intent
关于java - 切换蓝牙时无限 Activity 循环，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14188268/