我的代码是：
public class DeviceScanActivity extends AppCompatActivity/*ListActivity*/ {
//private LeDeviceListAdapter mLeDeviceListAdapter;
private BluetoothAdapter mBluetoothAdapter;
private boolean mScanning;
private Handler mHandler;
ArrayList<String> mylist = new ArrayList<String>();
private static final int REQUEST_ENABLE_BT = 1;
// Stops scanning after 10 seconds.
private static final long SCAN_PERIOD = 10000;
UsersAdapter adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//getActionBar().setTitle("abc");
mHandler = new Handler();
// Use this check to determine whether BLE is supported on the device. Then you can
// selectively disable BLE-related features.
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT).show();
finish();
}
// Initializes a Bluetooth adapter. For API level 18 and above, get a reference to
// BluetoothAdapter through BluetoothManager.
final BluetoothManager bluetoothManager =
(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = bluetoothManager.getAdapter();
// Checks if Bluetooth is supported on the device.
if (mBluetoothAdapter == null) {
Toast.makeText(this, R.string.error_bluetooth_not_supported, Toast.LENGTH_SHORT).show();
finish();
return;
}
// Construct the data source
ArrayList<ViewHolder> arrayOfUsers = new ArrayList<ViewHolder>();
// Create the adapter to convert the array to views
adapter = new UsersAdapter(this, arrayOfUsers);
ListView listView = (ListView) findViewById(R.id.mobile_list);
listView.setAdapter(adapter);
scanLeDevice(true);
ViewHolder newUser2 = new ViewHolder("adtv2","vvg2");
adapter.add(newUser2);
}
private void scanLeDevice(final boolean enable) {
if (enable) {
// Stops scanning after a pre-defined scan period.
ViewHolder newUser2 = new ViewHolder("adtv2","vvg2");
adapter.add(newUser2);
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
//invalidateOptionsMenu();
}
}, SCAN_PERIOD);
mScanning = true;
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
}
//invalidateOptionsMenu();
}
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
//mLeDeviceListAdapter.addDevice(device);
//mLeDeviceListAdapter.notifyDataSetChanged();
//ViewHolder newUser = new ViewHolder("Nathan", "San Diego");
String deviceName=null, deviceAddress=null;
if(device!=null)
deviceName= device.getName();
if (!(deviceName != null && deviceName.length() > 0))
deviceName = "unknown device";
if(device!=null)
deviceAddress= device.getAddress();
ViewHolder newUser = new ViewHolder(deviceName, deviceAddress);
ViewHolder newUser2 = new ViewHolder("adtv","vvg");
adapter.add(newUser2);
}
});
}
};
public class UsersAdapter extends ArrayAdapter<ViewHolder> {
public UsersAdapter(Context context, ArrayList<ViewHolder> users) {
super(context, 0, users);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
ViewHolder user = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
if (convertView == null) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.bt_details, parent, false);
}
// Lookup view for data population
TextView tvName = (TextView) convertView.findViewById(R.id.DeviceName);
TextView tvHome = (TextView) convertView.findViewById(R.id.DeviceAddress);
// Populate the data into the template view using the data object
tvName.setText(user.deviceName);
tvHome.setText(user.deviceAddress);
// Return the completed view to render on screen
return convertView;
}
}
public class ViewHolder {
String deviceName;
String deviceAddress;
public ViewHolder(String device, String __address) {
this.deviceName =device;
this.deviceAddress= __address;
}
}
}
**I am trying to list the available Bluetooth devices after scan.
我想这个方法没有被调用，因为listview只打印2条消息。它应该print3才能正常工作 LeScanCallback中的代码无法打印，所以我猜这个代码没有被调用。因此，蓝牙功能不起作用。**
bt_details.xml->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/DeviceName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Name" />
<TextView
android:id="@+id/DeviceAddress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Address" />
</LinearLayout>
listitem_device.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<!-- <TextView android:id="@+id/device_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="24dp"/>
<TextView android:id="@+id/device_address"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="12dp"/>-->
<ListView
android:id="@android:id/list"
android:layout_height="wrap_content"
android:layout_width="match_parent">
</ListView>
</LinearLayout>
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:orientation="vertical">
<!--tools:context=".ListActivity" -->
<ListView
android:id="@+id/mobile_list"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
listitem.xml
<?xml version="1.0" encoding="utf-8"?>
<!-- Single List Item Design -->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/label"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dip"
android:textSize="16dip"
android:textStyle="bold" >
</TextView>
我猜是BLUETOOTH发现的问题。我已经粘贴了代码和布局xml文件
答案 0 :(得分：1)
您在ListActivity上使用了错误的布局，似乎您复制了一个在线示例，并试图对其进行修改以执行本来不是针对（动态数据）的操作
我建议您更改
public class DeviceScanActivity extends ListActivity
收件人
public class DeviceScanActivity extends AppCompatActivity
并删除setListAdapter方法。
然后使用您的主要布局
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main); // here
然后，这些数据将正常工作
String[] mobileArray = {"Android","IPhone","WindowsMobile","Blackberry",
"WebOS","Ubuntu","Windows7","Max OS X"};
ArrayAdapter adapter = new ArrayAdapter<String>(this,
R.layout.listitem, mobileArray);
ListView listView = (ListView) findViewById(R.id.mobile_list);
listView.setAdapter(adapter);
但是，您想添加蓝牙设备，因此删除所有内容（或者至少确保首先运行），然后换个适配器，可能是一个自定义-start here，然后通过“使用自定义ArrayAdapter”部分进行阅读。
例如public class LeDeviceListAdapter extends ArrayAdapter< BluetoothDevice>
如果那是您的活动领域的适配器
public class DeviceScanActivity extends AppCompatActivity {
private LeDeviceListAdapter mLeDeviceListAdapter; // This here
然后，此代码应该有效
// in onCreate
mLeDeviceListAdapter = new LeDeviceListAdapter();
然后将您的监听器设置为仅使用内置的add方法
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
mLeDeviceListAdapter.add(device);
}
});
}
};
答案 1 :(得分：0)
我添加了
requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION);
private static final int PERMISSION_REQUEST_COARSE_LOCATION = 456;
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
switch (requestCode) {
case PERMISSION_REQUEST_COARSE_LOCATION: {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission granted, yay! Start the Bluetooth device scan.
scanLeDevice(true);
} else {
// Alert the user that this application requires the location permission to perform the scan.
}
}
}
}
将build.gradle中的minSdkVersion更改为23 现在BLE扫描效果很好